How many panels ? ( to run 230 volt sprinkler pump 30 minutes a day?)
Eeyore
I'm dying to hear the answer ! With or without battery storage and how
the 2 methods compare in cost.
Graham
Ron Rosenfeld
Without some kind of storage, daily pumping won't be possible. But the
recommendations made for number of panels, of the type specified by the OP,
and (at least in my case) optimally sited and positioned (fixed-tilt and
azimuth) are:
RR: 10 panels
GG: (1st try) 154 panels
GG: (2nd try) 17- 50W Panels
GG: (3rd try) (C5 / C12) = 10.3 (11)
The OP has not posted back with any clarifying information, so it's hard to
speculate regarding storage. If he were grid-connected, though, then
storage would be unnecessary and the number of panels could be sized based
on average annual insolation instead of worst month insolation, depending
on the economics of grid-tie in his location.
--ron
jp838
wrote:
The guy who opened the thread never replied to anyone :)
It's just about wanabe scientists oversized egos!
BTW, watering - as air-conditioning, water desalination, ... - is a
very good job for solar energy: the less the sun shine, the less you
have to water; coupled with a windmill, it would be perfect - wind can
dries - so here too, the less wind the less you have to water.
Sholl
bea...@gmail.com
wrote:
It looks like this:
A2 Daily load = 1250Wh
A4 Inverter Efficiency = 85%
A5 Account for inverter inefficiency - Load (A2/A4) = 1470.5
A7 System Voltage = 12
A8 Total A-hr demand per day (A5 / A7) = 122.55
B1 Number of days of autonomy = 1
B2 Maximum allowable depth of discharge = 70%
B3 Battery capacity (A8 x B1 / B2) = 175Ah
B4 Lowest 24 hour average temperature =15c
B5 Temperature correction factor =.97
B6 Adjusted battery capacity (B3 / B5) = 180.5
B7 Selected Battery
B8 Selected battery discharge rate 100
B9 A-hr capacity of selected battery = 180Ah
B10 Number of batteries in parallel (B6 / B9, rounded off) = 1
B11 Number of batteries in series (A7 / battery voltage) =1
B12 Check Capacity of selected battery at l00 Hr rate = 180
B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 180
B14 Daily depth of discharge (100 x A8 / B13) = 68%
C1 Design tilt
C2 Design month
C3 Total energy demand per day (A8) =122.55Ah
C4 Battery efficiency = 90%
C5 Array output required per day (C3 / C4) = 136.2
C6 Peak sun hours at design tilt for design month = 5
C7 Selected module
C8 Selected module I at 14 volts at NOCT 2.94A
C9 Selected module nominal operating voltage. = 12V
C10 Guaranteed current (C8 x 0.9) = 2.65A
C11 Number of modules in series (A7 / C9) = 1
C12 Output per module (C10 x C6) = 13.2Ah
C13 Number of parallel strings of modules (C5 / C12) = 10.3
With batteries and a silly 20% added to daily load at “A8” for system
losses. And while Ron whines about it, have a look at his post because
this is where he added the 20%, right after accounting for the
inverter inefficiency.
A2 Daily load = 1250Wh
A4 Inverter Efficiency = 85%
A5 Account for inverter inefficiency - Load (A2/A4) = 1470.59
A7 System Voltage = 12
A8 Total A-hr demand per day (A5 / A7) = 144.17 (rons 20% added)
B1 Number of days of autonomy = 1
B2 Maximum allowable depth of discharge = 70%
B3 Battery capacity (A8 x B1 / B2) = 206Ah
B4 Lowest 24 hour average temperature = 15c
B5 Temperature correction factor =.97
B6 Adjusted battery capacity (B3 / B5) = 212.Ah
B7 Selected Battery
B8 Selected battery discharge rate 100
B9 A-hr capacity of selected battery = 212Ah
B10 Number of batteries in parallel (B6 / B9, rounded off) = 1
B11 Number of batteries in series (A7 / battery voltage) =1
B12 Check Capacity of selected battery at l00 Hr rate = 212
B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 212
B14 Daily depth of discharge (100 x A8 / B13) = 68%
C1 Design tilt
C2 Design month
C3 Total energy demand per day (A8) =144.17Ah
C4 Battery efficiency = 90% (Ron likes 80% here. If you use 80%
the
required panels come to 13.62)
C5 Array output required per day (C3 / C4) = 160.19
C6 Peak sun hours at design tilt for design month = 5
C7 Selected module
C8 Selected module I at 14 volts at NOCT 2.94A
C9 Selected module nominal operating voltage. = 12V
C10 Guaranteed current (C8 x 0.9) = 2.65A
C11 Number of modules in series (A7 / C9) = 1
C12 Output per module (C10 x C6) = 13.23Ah
C13 Number of parallel strings of modules (C5 / C12) = 12.11
These sizings take into account the all "losses" within system sizing:
INVERTER
1) Inverter efficiency
BATTERIES
1) Maximum allowable Depth Of Discharge
2) Temperature correction
PANELS
1) Panels guaranteed current
2) Battery efficiency
Just adding 20% at any point is not good design practice. Every part
of system design depends on all the numbers in the right places.
Ron says you should take his word for it.
George says here is the formula, have fun, take nobodies word for it,
work it out for yourself.
wmbjk...@citlink.net
>Ron says you should take his word for it.
Ron wrote the single best post in this thread, answering the OP's
question directly and properly mentioned better solutions. If you
could learn to think and write half as well then you might not be the
butt of so many jokes.
>George says here is the formula, have fun, take nobodies word for it,
>work it out for yourself.
George has said a *lot*, beginning with a display of his confusion
about the difference between watts and amps, and his resultant
ludicrous recommendation of 154 panels. Only after everybody made fun
of him did he eventually settle on 10.3 panels, almost matching Ron's
estimate... many days and dozens of posts later. If George were
selling deeezines, he'd need to post his calculations on Usenet every
time to see if they were correct, or even in the ballpark.
Fortunately, nobody with an Internet connection would be dumb enough
to hire him.
Wayne
bea...@gmail.com
Still no numbers to support his claims. Talking the talk is not the
same as walking the walk.
wayne is a talker.
bea...@gmail.com
> On Thu, 03 Jul 2008 05:10:11 +0100, Eeyore
>
This is the indication of rons true (in)ability
"so it's hard to speculate regarding storage"
There is no speculation involved. If you know the daily load, which we
do (122.55Ah), the battery is sized to meet this load.
The daily load (122.55Ah) is a given. That is the pump as specified by
the OP.
The other given is the panels 50W (2.94A) also specified by the OP.
Every thing in between is a straight forward calculation.
Here is a bit of silliness to ponder;
Panels - inverter - no batteries:
Load 2500W
Inverter 85% efficient
Panels 2.6 A each(adjusted for real output)
The load of 2500W at 12V(Panel voltage) = 208 Amps
Adjusted for inverter inefficiency = 244.7Amps
244.7 / 2.6 = 94.12 panels
Problem - Not enough to start pump. Pump requires ~ 5 times 2500 Watts
to start = 12500W
Adjusted for inverter inefficiency = 14706 Watts (1225.5A)
1225.5A / 2.6A =
471.3 panels required.
Go on, add it up yourself.
It's as silly as a bent wheel, sure, but what a hoot. And it requires
only half an hours full sun a day.
wmbjk...@citlink.net
>The daily load (122.55Ah) is a given. That is the pump as specified by
>the OP.
>
>The other given is the panels 50W (2.94A) also specified by the OP.
>
>Every thing in between is a straight forward calculation.
...only for those who don't have the experience to know about readily
available alternatives. For example, I'll be installing a 10gpm setup
for a friend soon. Array will be ~350W (depends on what modules are
available at best price) See curves for 11SQF-2 here
http://lib.store.yahoo.net/lib/wind-sun/SQFlex.pdf. Daily output will
be in the 3000 to 4500 gallon range (some 15 times the OP's volume
needs). So while you're busying yourself hilariously trying to fit
every application into your GIGO spreadsheet no matter how
inappropriately, normal people choose the best and most cost-effective
hardware to suit their application.
>The load of 2500W at 12V(Panel voltage) = 208 Amps
Only a true ghinius could start off with such a mind-bogglingly
moronic assumption. The rest of your calculations are equally idiotic.
>471.3 panels required.
Oh I see, this exercise was a transparent attempt to excuse your
original 154 panel recommendation. Lame. I hope you wasted lots of
time on it.
Your first and only response to embarrassment is always to try to
distract attention from your mistakes by writing ever more ridiculous
BS. Since your preference is to pretend that you're something you're
not, why not pretend to be a normal person, and simply own up to your
blunders?
"The first rule of holes: When you're in one, stop digging."
Wayne
bea...@gmail.com
> On Thu, 3 Jul 2008 17:33:58 -0700 (PDT), beal...@gmail.com wrote:
> >The daily load (122.55Ah) is a given. That is the pump as specified by
> >the OP.
>
> >The other given is the panels 50W (2.94A) also specified by the OP.
>
> >Every thing in between is a straight forward calculation.
>
> ...only for those who don't have the experience to know about readily
> available alternatives.
Sorry wayne, it remains a straight forward calculation. Only the
numbers change.
> For example, I'll be installing a 10gpm setup
> for a friend soon.
God help him.
> Array will be ~350W (depends on what modules are
> available at best price)
Ah, the famous guess "Principle" Less than 350 Watts. What does the
pump actually use?
> See curves for 11SQF-2 herehttp://lib.store.yahoo.net/lib/wind-sun/SQFlex.pdf.
Page Not Found
The page you are trying to locate could not be found. Please try again
later. We apologize for the inconvenience.
> Daily output will
> be in the 3000 to 4500 gallon range (some 15 times the OP's volume
> needs).
How many watts does the pump draw?
> So while you're busying yourself hilariously trying to fit
> every application into your GIGO spreadsheet no matter how
> inappropriately, normal people choose the best and most cost-effective
> hardware to suit their application.
The question was answered based on data provided.
>
> >The load of 2500W at 12V(Panel voltage) = 208 Amps
>
> Only a true ghinius could start off with such a mind-bogglingly
> moronic assumption. The rest of your calculations are equally idiotic.
2500(W)/12(V) = 208.33(A) rounded off to 208. No assumption involved.
>
> >471.3 panels required.
>
> Oh I see, this exercise was a transparent attempt to excuse your
> original 154 panel recommendation. Lame. I hope you wasted lots of
> time on it.
Item was marked as "SILLINESS" to begin with. It seems that this is
necessary for you. Sorry you missed the point.
>
> Your first and only response to embarrassment is always to try to
> distract attention from your mistakes by writing ever more ridiculous
> BS. Since your preference is to pretend that you're something you're
> not, why not pretend to be a normal person, and simply own up to your
> blunders?
>
> "The first rule of holes: When you're in one, stop digging."
>
> Wayne
Tell us about your system. What are your loads? What do they draw? How
long are they run? And let's not forget, How does increasing the load
reduce resistance in conductors?
Ron Rosenfeld
>"so it's hard to speculate regarding storage"
>
>
>There is no speculation involved. If you know the daily load, which we
>do (122.55Ah), the battery is sized to meet this load.
George is now adding mind-reading to his so-called talents.
He "knows" the OP will want *battery* storage, even though the OP did not
mention anything about the kind of storage that might be appropriate for
his application. And also that he will want only 1 day of autonomy to run
his pump daily.
But even with regard to this assumption of his, note that GG writes the
following:
GG: There is no speculation involved. If you know the daily load, which we
do (122.55Ah), the battery is sized to meet this load.
GG: it remains a straight forward calculation.
In a previous post, he figured one day of autonomy.
GG:
12V system
2250 Wh/day
1 Day autonomy
300Ah Battery
66% Daily DOD
5 PSH/Day
17- 50W Panels
In another post, he is also recommending one day of autonomy, but comes up
with a different sized battery:
GG:
B1 Number of days of autonomy = 1
B6 Adjusted battery capacity (B3 / B5) = 180.5
B9 A-hr capacity of selected battery = 180Ah
B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 180
B14 Daily depth of discharge (100 x A8 / B13) = 68%
B14 Daily depth of discharge (100 x A8 / B13) = 68%
It seems GG's "straight forward calculation" can give different results
depending on ... whimsy?
Same pump; same number of days of autonomy; two very different sized
batteries?
--ron
bea...@gmail.com
Ron, you are telling a lie. Yes Same pump; same number of days of
autonomy;
Different number of Ahs. It seems that wayne is not the only one who
misquotes.
This is what was said;
A2 Daily load = 1250Wh
A4 Inverter Efficiency = 85%
A5 Account for inverter inefficiency - Load (A2/A4) = 1470.5
A7 System Voltage = 12
A8 Total A-hr demand per day (A5 / A7) = 122.55
B1 Number of days of autonomy = 1
B2 Maximum allowable depth of discharge = 70%
B3 Battery capacity (A8 x B1 / B2) = 175Ah
B4 Lowest 24 hour average temperature =15c
B5 Temperature correction factor =.97
B6 Adjusted battery capacity (B3 / B5) = 180.5
B7 Selected Battery
B8 Selected battery discharge rate 100
B9 A-hr capacity of selected battery = 180Ah
B10 Number of batteries in parallel (B6 / B9, rounded off) = 1
B11 Number of batteries in series (A7 / battery voltage) =1
B12 Check Capacity of selected battery at l00 Hr rate = 180
B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 180
B14 Daily depth of discharge (100 x A8 / B13) = 68%
This is correct and everyone can follow the calculation step by step.
There is nothing hidden.
You're not fooling anybody.
wmbjk...@citlink.net
Just the usual GIGO resulting from spreadsheet abuse.
>>
>> Same pump; same number of days of autonomy; two very different sized
>> batteries?
>> --ron
Classic ghinius self-busting expirteeze.
>Different number of Ahs.
Ron quoted you correctly - "There is no speculation involved. If you
know the daily load, which we do (122.55Ah), the battery is sized to
meet this load."
So how can there be a "Different number of Ahs"?
>> GG: it remains a straight forward calculation.
Yes, but only for those who are doing the calculations for some
purpose other than trying to cover up blunders.
>There is nothing hidden.
True, your lack of experience shines more brightly with every post.
Wayne
bea...@gmail.com
2250 Wh/day and A2 Daily load = 1250Wh
>
> >> GG: it remains a straight forward calculation.
>
> Yes, but only for those who are doing the calculations for some
> purpose other than trying to cover up blunders.
>
> >There is nothing hidden.
>
> True, your lack of experience shines more brightly with every post.
>
> Wayne
Tell us about your system. What are your loads? What do they draw? How
Ron Rosenfeld
>Ron, you are telling a lie. Yes Same pump; same number of days of
>autonomy;
>
>Different number of Ahs. It seems that wayne is not the only one who
>misquotes.
George,
Since it was you who specified different battery sizes given the same
question by the OP, it is clear who is being disingenuous.
You know, if you spent a fraction of the time educating yourself and
researching your stuff as you do trying to cover up your errors, you might
actually learn something worthwhile.
What data source did you use to get your values for what seems to be your
most recent guess at an acceptable system (11 - 50Watt panels and a 180Ah
battery)?
The data I have for Kilauea show that for 50 watt panels with a NOCT of
45.2°C, temperature coeff of power of -0.5%/°C, and an efficiency of 13% at
STC, that your recommendation of 11 panels and 180AH of battery storage
will result in a shortened battery life and a significant capacity
shortage.
I didn't have the figures for your 180Ah battery, so I used Trojan T-105
which have a 225 Ah capacity, a minimum state of charge of 30% and an 85%
efficiency. However, to make it more compatible with your 180Ah battery, I
changed the efficiency to 90%.
With 11 panels and 2 "Ghio-modifed" T-105's in series, there is a capacity
shortage of 23% over the course of a year, and battery life is 42% of what
it would be with an optimal system. It is also more expensive than the
optimal system.
I suppose you will now try to explain how your 180Ah battery will prevent
the shortfall and have an improved battery life compared with a 225Ah
battery, that has the same allowable depth of discharge and efficiency. Or
maybe you'll just revert to type and continue with your insults <sigh>.
--ron
bea...@gmail.com
> On Sat, 5 Jul 2008 06:35:05 -0700 (PDT), beal...@gmail.com wrote:
> >Ron, you are telling a lie. Yes Same pump; same number of days of
> >autonomy;
>
> >Different number of Ahs. It seems that wayne is not the only one who
> >misquotes.
>
> George,
>
> Since it was you who specified different battery sizes given the same
> question by the OP, it is clear who is being disingenuous.
You told a lie and got caught.
>
> You know, if you spent a fraction of the time educating yourself and
> researching your stuff as you do trying to cover up your errors, you might
> actually learn something worthwhile.
I learned that you will misquote, quote out of context and tell
outright lies.
>
> What data source did you use to get your values for what seems to be your
> most recent guess at an acceptable system (11 - 50Watt panels and a 180Ah
> battery)?
Watts and panels from OP.
>
> The data I have for Kilauea show that for 50 watt panels with a NOCT of
> 45.2°C, temperature coeff of power of -0.5%/°C, and an efficiency of 13% at
> STC, that your recommendation of 11 panels and 180AH of battery storage
> will result in a shortened battery life and a significant capacity
> shortage.
Show us the numbers. OH, sorry, I forgot, you're an idiot and can't
prove any claim you might make
>
> I didn't have the figures for your 180Ah battery, so I used Trojan T-105
> which have a 225 Ah capacity, a minimum state of charge of 30% and an 85%
> efficiency. However, to make it more compatible with your 180Ah battery, I
> changed the efficiency to 90%.
Ah yes. The T105 Trojan, Trojan make condoms, don't they? Your amateur
status is showing.
>
> With 11 panels and 2 "Ghio-modifed" T-105's in series, there is a capacity
> shortage of 23% over the course of a year, and battery life is 42% of what
> it would be with an optimal system. It is also more expensive than the
> optimal system.
Show us the numbers. OH, sorry, I forgot, you're an idiot and can't
prove any claim you might make. Damn, I did it again.
>
> I suppose you will now try to explain how your 180Ah battery will prevent
> the shortfall and have an improved battery life compared with a 225Ah
> battery, that has the same allowable depth of discharge and efficiency. Or
> maybe you'll just revert to type and continue with your insults <sigh>.
180Ah is the correct capacity for the job. You have yet to prove it
wrong.
bea...@gmail.com
when we change the battery capacity to 225 Ahs.
Same formula, same data with the battery capacity changed to 225Ahs at
B9, which funnily enough is labeled "A-hr capacity of selected
battery". The reason for this label is that this is where "YOU" get to
specify the battery you choose to use. You see, while ron whinges
about the calculated minimum battery size, "YOU" get to specify "YOUR"
requirements within the formula. The only proviso is thet you do not
change any of the actual calculations.
A2 Daily load = 1250Wh
A4 Inverter Efficiency = 85%
A5 Account for inverter inefficiency - Load (A2/A4) = 1470.5
A7 System Voltage = 12
A8 Total A-hr demand per day (A5 / A7) = 122.55
B1 Number of days of autonomy = 1
B2 Maximum allowable depth of discharge = 70%
B3 Battery capacity (A8 x B1 / B2) = 175Ah
B4 Lowest 24 hour average temperature =15c
B5 Temperature correction factor =.97
B6 Adjusted battery capacity (B3 / B5) = 180.5
B7 Selected Battery
B8 Selected battery discharge rate 100
B9 A-hr capacity of selected battery = 225Ah
B10 Number of batteries in parallel (B6 / B9, rounded off) = 1
B11 Number of batteries in series (A7 / battery voltage) =1
B12 Check Capacity of selected battery at l00 Hr rate = 225
B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 225
B14 Daily depth of discharge (100 x A8 / B13) = 54.47%
And there you have it, the Daily depth of discharge has dropped to
54.47%
C1 Design tilt
C2 Design month
C3 Total energy demand per day (A8) =122.55Ah
C4 Battery efficiency = 90%
C5 Array output required per day (C3 / C4) = 136.2
C6 Peak sun hours at design tilt for design month = 5
C7 Selected module
C8 Selected module I at 14 volts at NOCT 2.94A
C9 Selected module nominal operating voltage. = 12V
C10 Guaranteed current (C8 x 0.9) = 2.65A
C11 Number of modules in series (A7 / C9) = 1
C12 Output per module (C10 x C6) = 13.2Ah
C13 Number of parallel strings of modules (C5 / C12) = 10.3
This formula is correct and will correctly size a stand alone PV
system. Neither Tweedledee nor Tweedledum can prove otherwise. Of
course they will keep saying it is incorrect, but never a shred of
mathematical proof will ever be forthcoming.
Of course there is still the problem of designing for an autonomy of
only one day. It is more common to design for several days autonomy.
So let's up the ante and change the system for 5 days autonomy. We
will keep the Trojans so we can clearly see the change;
A2 Daily load = 1250Wh
A4 Inverter Efficiency = 85%
A5 Account for inverter inefficiency - Load (A2/A4) = 1470.5
A7 System Voltage = 12
A8 Total A-hr demand per day (A5 / A7) = 122.55
B1 Number of days of autonomy = 5
B2 Maximum allowable depth of discharge = 70%
B3 Battery capacity (A8 x B1 / B2) = 875.35Ah
B4 Lowest 24 hour average temperature =15c
B5 Temperature correction factor =.97
B6 Adjusted battery capacity (B3 / B5) = 902.42
B7 Selected Battery
B8 Selected battery discharge rate 100
B9 A-hr capacity of selected battery = 225Ah
B10 Number of batteries in parallel (B6 / B9, rounded off) = 4
B11 Number of batteries in series (A7 / battery voltage) =1
B12 Check Capacity of selected battery at l00 Hr rate = 225
B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 900
B14 Daily depth of discharge (100 x A8 / B13) = 13.62%
C1 Design tilt
C2 Design month
C3 Total energy demand per day (A8) =122.55Ah
C4 Battery efficiency = 90%
C5 Array output required per day (C3 / C4) = 136.2
C6 Peak sun hours at design tilt for design month = 5
C7 Selected module
C8 Selected module I at 14 volts at NOCT 2.94A
C9 Selected module nominal operating voltage. = 12V
C10 Guaranteed current (C8 x 0.9) = 2.65A
C11 Number of modules in series (A7 / C9) = 1
C12 Output per module (C10 x C6) = 13.2Ah
C13 Number of parallel strings of modules (C5 / C12) = 10.3
wmbjk...@citlink.net
That does not explain your making multiple battery-size
recommendations. Which one do you believe is correct? Or is this like
your "20 liters per week/fortnight" fuel consumption, or your
"150/200A, 150/8.5 Ohm" rheostat, or your "7/15" year-old system,
where readers are supposed to imagine that all versions of your
stories must somehow be correct?
Wayne
wmbjk...@citlink.net
>While we wait
Who is "we"? Do you imagine that your cargo cult has more than a
single member?
Wayne
Ron Rosenfeld
>While we wait for ron's next tirade of nonsense let's see what happens
>when we change the battery capacity to 225 Ahs.
George,
YOU are the only one who has been lying. And all you have been spewing is
nonsense.
YOU have falsely claimed that I recommended some battery size to the OP.
YOU have done this by taking my recommendation for a *panel array size*,
and running it through your useless (in your hands) spreadsheet, using
inputs that you have made up. And YOUR spreadsheet provides for the same
20% factor in panel array sizing, which YOU obviously are unable to
recognize!
YOU cannot even copy the OP's panel specifications to your spreadsheet
properly!
YOU have recommended multiple systems that won't meet the requirement of
daily running of the OP's system.
YOUr last recommendation will NOT run the OP's system 24/7 at his location.
Simple simulations show a 23% shortfall using a larger battery! Of course,
you have never provided full specifications for your 180Ah battery which
was the last one you recommended, so a more precise shortfall of your last
proposed system cannot be predicted.
YOUR lowest recommendation for panels (amongst your many recommendations)
is 10% MORE than my recommendation, yet you persist in claiming that mine
is oversized!
YOU really are a piece of work.
--ron
bea...@gmail.com
As I have already predicted, lots of claims from Tweedledee and
Tweedledum and no maths to back up their claims.
bea...@gmail.com
> >While we wait for ron's next tirade of nonsense let's see what happens
> >when we change the battery capacity to 225 Ahs.
>
> George,
>
> YOU are the only one who has been lying. And all you have been spewing is
> nonsense.
>
> YOU have falsely claimed that I recommended some battery size to the OP.
You offered Trojan T105s. Sound pretty specific.
>
> YOU have done this by taking my recommendation for a *panel array size*,
> and running it through your useless (in your hands) spreadsheet, using
> inputs that you have made up. And YOUR spreadsheet provides for the same
> 20% factor in panel array sizing, which YOU obviously are unable to
> recognize!
No. I sized the required system, in the correct order and did not add
20% on top of the inverter adjustment to the daily load.
>
> YOU cannot even copy the OP's panel specifications to your spreadsheet
> properly!
What! No proof?
>
> YOU have recommended multiple systems that won't meet the requirement of
> daily running of the OP's system.
A2 Daily load = 1250Wh
A4 Inverter Efficiency = 85%
A5 Account for inverter inefficiency - Load (A2/A4) = 1470.5
A7 System Voltage = 12
A8 Total A-hr demand per day (A5 / A7) = 122.55
B1 Number of days of autonomy = 1
B2 Maximum allowable depth of discharge = 70%
B3 Battery capacity (A8 x B1 / B2) = 175Ah
B4 Lowest 24 hour average temperature =15c
B5 Temperature correction factor =.97
B6 Adjusted battery capacity (B3 / B5) = 180.5
B7 Selected Battery
B8 Selected battery discharge rate 100
B9 A-hr capacity of selected battery = 225Ah
B10 Number of batteries in parallel (B6 / B9, rounded off) = 1
B11 Number of batteries in series (A7 / battery voltage) =1
B12 Check Capacity of selected battery at l00 Hr rate = 225
B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 225
B14 Daily depth of discharge (100 x A8 / B13) = 54.47%
C1 Design tilt
C2 Design month
C3 Total energy demand per day (A8) =122.55Ah
C4 Battery efficiency = 90%
C5 Array output required per day (C3 / C4) = 136.2
C6 Peak sun hours at design tilt for design month = 5
C7 Selected module
C8 Selected module I at 14 volts at NOCT 2.94A
C9 Selected module nominal operating voltage. = 12V
C10 Guaranteed current (C8 x 0.9) = 2.65A
C11 Number of modules in series (A7 / C9) = 1
C12 Output per module (C10 x C6) = 13.2Ah
C13 Number of parallel strings of modules (C5 / C12) = 10.3
Prove it wrong.
>
> YOUr last recommendation will NOT run the OP's system 24/7 at his location.
> Simple simulations show a 23% shortfall using a larger battery! Of course,
> you have never provided full specifications for your 180Ah battery which
> was the last one you recommended, so a more precise shortfall of your last
> proposed system cannot be predicted.
Prove it. You claim a very precise 23% short fall. All you have to do
is show the numbers.
>
> YOUR lowest recommendation for panels (amongst your many recommendations)
> is 10% MORE than my recommendation, yet you persist in claiming that mine
> is oversized!
With your 20% added to the daily load, exactly where you put it:
A2 Daily load = 1250Wh
A4 Inverter Efficiency = 85%
A5 Account for inverter inefficiency - Load (A2/A4) = 1470.59
A7 System Voltage = 12
A8 Total A-hr demand per day (A5 / A7) = 144.17 (rons 20% added)
B1 Number of days of autonomy = 1
B2 Maximum allowable depth of discharge = 70%
B3 Battery capacity (A8 x B1 / B2) = 206Ah
B4 Lowest 24 hour average temperature = 15c
B5 Temperature correction factor =.97
B6 Adjusted battery capacity (B3 / B5) = 212.Ah
B7 Selected Battery
B8 Selected battery discharge rate 100
B9 A-hr capacity of selected battery = 212Ah
B10 Number of batteries in parallel (B6 / B9, rounded off) = 1
B11 Number of batteries in series (A7 / battery voltage) =1
B12 Check Capacity of selected battery at l00 Hr rate = 212
B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 212
B14 Daily depth of discharge (100 x A8 / B13) = 68%
C1 Design tilt
C2 Design month
C3 Total energy demand per day (A8) =144.17Ah
C4 Battery efficiency = 90%
(Ron likes 80% here. If you use 80% the required panels come to 13.62)
C5 Array output required per day (C3 / C4) = 160.19
C6 Peak sun hours at design tilt for design month = 5
C7 Selected module
C8 Selected module I at 14 volts at NOCT 2.94A
C9 Selected module nominal operating voltage. = 12V
C10 Guaranteed current (C8 x 0.9) = 2.65A
C11 Number of modules in series (A7 / C9) = 1
C12 Output per module (C10 x C6) = 13.23Ah
C13 Number of parallel strings of modules (C5 / C12) = 12.11
Ron Rosenfeld
The math to calculate the panel array size was provided in my first post,
but it seems that you've not been able to understand it. All you can do is
rant about a 20% overestimate for a battery about which I wrote nothing.
And you keep claiming that my 10 panel array is oversized by 20%; whereas
your 11 panel array (or maybe your 17 panel or 154 panel recommendations)
is OK.
You can't even enter the OP's data correctly into your spreadsheet.
But if you want more real data, all you need to do is provide the specs on
your 180Ah battery, and the simulation is simple to do.
Give me the specs on your 180 Ah battery, and I'll give you the numbers for
a simulation of your 11 panel, 180 Ah battery system for Kilauea, HI.
George's Battery:
Nominal Capacity: 180Ah
Nominal Voltage: ???
Round Trip Efficiency ??
Min state of charge: ??
Float life: ?? yrs
Max charge rate: ? A/Ah
Max charge current: ? A
Lifetime throughput: ? kWh
Also a Capacity curve (A vs Ah) and a Lifetime curve (DOD vs Cycles to
failure)
Because of the location, there's probably no need for you to supply a Temp
vs capacity curve or coefficient. The temperatures don't vary that much
from the annual mean of 24°C.
--ron
bea...@gmail.com
My, my, Tweedledee is busy today.
>
> The math to calculate the panel array size was provided in my first post,
> but it seems that you've not been able to understand it. All you can do is
> rant about a 20% overestimate for a battery about which I wrote nothing.
Trojan 225Ah T105s
>
> And you keep claiming that my 10 panel array is oversized by 20%; whereas
> your 11 panel array (or maybe your 17 panel or 154 panel recommendations)
> is OK.
It is not ten panels , it is 11. You added 20% on top of the daily
load right after you adjusted the load for inverter losses.
>
> You can't even enter the OP's data correctly into your spreadsheet.
2.94A adjusted to 2.65A for losses.
>
> But if you want more real data, all you need to do is provide the specs on
> your 180Ah battery, and the simulation is simple to do.
The 180 Ah capacity is the minimum required for the system as
calculated from OPs data. At B9 actual battery can be specified. you
are the only person so far to suggest a particular battery i.e. Trojan
T105s. As you feel that this battery is suitable for the application I
included it in the formula. The following is the result
A2 Daily load = 1250Wh
A4 Inverter Efficiency = 85%
A5 Account for inverter inefficiency - Load (A2/A4) = 1470.5
A7 System Voltage = 12
A8 Total A-hr demand per day (A5 / A7) = 122.55
B1 Number of days of autonomy = 1
B2 Maximum allowable depth of discharge = 70%
B3 Battery capacity (A8 x B1 / B2) = 175Ah
B4 Lowest 24 hour average temperature =15c
B5 Temperature correction factor =.97
B6 Adjusted battery capacity (B3 / B5) = 180.5
B7 Selected Battery
B8 Selected battery discharge rate 100
B9 A-hr capacity of selected battery = 225Ah
B10 Number of batteries in parallel (B6 / B9, rounded off) = 1
B11 Number of batteries in series (A7 / battery voltage) =1
B12 Check Capacity of selected battery at l00 Hr rate = 225
B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 225
B14 Daily depth of discharge (100 x A8 / B13) = 54.47%
C1 Design tilt
C2 Design month
C3 Total energy demand per day (A8) =122.55Ah
C4 Battery efficiency = 90%
C5 Array output required per day (C3 / C4) = 136.2
C6 Peak sun hours at design tilt for design month = 5
C7 Selected module
C8 Selected module I at 14 volts at NOCT 2.94A
C9 Selected module nominal operating voltage. = 12V
C10 Guaranteed current (C8 x 0.9) = 2.65A
C11 Number of modules in series (A7 / C9) = 1
C12 Output per module (C10 x C6) = 13.2Ah
C13 Number of parallel strings of modules (C5 / C12) = 10.3
>
> Give me the specs on your 180 Ah battery, and I'll give you the numbers for
> a simulation of your 11 panel, 180 Ah battery system for Kilauea, HI.
The battery capacity is, as has been already stated, the minimum
required to do the job.
>
> George's Battery:
>
> Nominal Capacity: 180Ah
Correct
> Nominal Voltage: ???
12V
> Round Trip Efficiency ??
It didn't go anywhere. Perhaps you mean the battery efficiency.
Already in the formula (C4)
> Min state of charge: ??
0%. Actually I think that you mean Maximum allowable depth of
discharge (B2)
> Float life: ?? yrs
> Max charge rate: ? A/Ah
C10 is the correct charge rate.
> Max charge current: ? A
See above
> Lifetime throughput: ? kWh
All of them
>
> Also a Capacity curve (A vs Ah) and a Lifetime curve (DOD vs Cycles to
> failure)
>
> Because of the location, there's probably no need for you to supply a Temp
> vs capacity curve or coefficient. The temperatures don't vary that much
> from the annual mean of 24°C.
You talk a lot of nonsense Tweedledee.
None of your questions mean anything in relation to the minimum
battery capacity as stated. At (B9) you enter the battery capacity of
the battery you choose. You chose Trojan T105s at 225 ah. I put that
in the formula. The only thing that changed was the daily DoD. It fell
from 68% to 54%.
If there are any other parameters you wish to change, you know, like
removing the 20% to the daily load you insist should happen just after
you have adjusted the daily load to account for the inverter's
inefficiency, I will be happy to change the sample sizing.
> --ron
wmbjk...@citlink.net
<ronros...@nospam.org> wrote:
>You can't even enter the OP's data correctly into your spreadsheet.
>
>But if you want more real data, all you need to do is provide the specs on
>your 180Ah battery, and the simulation is simple to do.
>
>
>Give me the specs on your 180 Ah battery, and I'll give you the numbers for
>a simulation of your 11 panel, 180 Ah battery system for Kilauea, HI.
>
>George's Battery:
>
>Nominal Capacity: 180Ah
>Nominal Voltage: ???
>Round Trip Efficiency ??
>Min state of charge: ??
>Float life: ?? yrs
>Max charge rate: ? A/Ah
>Max charge current: ? A
>Lifetime throughput: ? kWh
>
>Also a Capacity curve (A vs Ah) and a Lifetime curve (DOD vs Cycles to
>failure)
>
>Because of the location, there's probably no need for you to supply a Temp
>vs capacity curve or coefficient. The temperatures don't vary that much
>from the annual mean of 24�C.
>--ron
Some save time by substituting rules of thumb for manufacturers'
specs. This makes sense on Planet Ghio because somebody with a few
years of experience with a propane tank and a 1kWh per day solar setup
is obviously sure to know more than companies that build batteries...
or anybody for that matter. In fact, our very own power consultant
ghinius' brain has so many RoTs crammed into it that there simply
isn't any room left for learning anything useful, er... new. It's
apparently a case of stagnation due to knowing too much! <snorf>
Wayne
Ron Rosenfeld
>Prove it. You claim a very precise 23% short fall. All you have to do
>is show the numbers.
That was for a hypothetical battery, which was proposed only because *you*
kept blathering on about battery recommendations, and misquoting (a kind
way of saying "lying" about) my panel array recommendation size.
With a hypothetical Trojan T105 battery (modified to 90% efficiency) in a
50 watt/panel, 11 panel system, that shortfall is predictable. I did not
propose that it be used in the system; it was proposed only because you did
not quote any particular battery or specifications other than the 180Ah
battery figure, which you use for the 100 hr rating.
>> B9 A-hr capacity of selected battery = 180Ah
>> B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 180
That would mean that that your proposed battery can output a current of
1.8A for 100 hrs.
You also claim that your battery has a
>> C4 Battery efficiency = 90%
and a
>> B2 Maximum allowable depth of discharge = 70%
I don't have a battery in my database that matches those specifications of
yours. The closest is the Trojan T105 which has a capacity at the 20 hr
rate of 225Ah, and so would obviously be better than 180Ah at the 100 hr
rate. But its round trip efficiency is only 85%, vs the 90% in the battery
you are quoting.
Changing the efficiency to 90% in the specifications for the T105 and
leaving everything else the same results in the simulation showing a 23%
shortfall.
But I thought you would want to specify your own battery, to get a more
realistic result of your proposed 11 panel system with a 180Ah battery (at
the 100 hr rate).
If you are really interested in the simulation results of your proposed
system with a hypothetical T105 modified to 90% efficiency, I could post
that. But to what end -- that battery does not exist.
I think the simulation would be of more value with a "real" battery that
comes close to the parameters you are using. I could use the unmodified
T105, which has a 27% shortfall (if I recall correctly, or any other real
battery for which you can provide the specifications I mentioned.
--ron
Ron Rosenfeld
>You talk a lot of nonsense Tweedledee.
>
>None of your questions mean anything in relation to the minimum
>battery capacity as stated. At (B9) you enter the battery capacity of
>the battery you choose. You chose Trojan T105s at 225 ah. I put that
>in the formula. The only thing that changed was the daily DoD. It fell
>from 68% to 54%.
You are the only one who is making those entries. I don't use that
spreadsheet, and I surely would not have you make data entry for me.
Just to refresh your memory, here is the math:
---------------------
AC Load 2500W x 0.5hrs/day --> 1250 watt-hrs/day
Inverter Efficiency 85%
Adjusted AC Load 1471 Watt-hrs/day
Nominal system voltage 12V (This is appropriate for your panels)
Total load in AH 123 amp-hrs per day
System Losses, etc 20%
Total Required 147 amp-hrs per day
Worst month insolation 5.08 kWh/m^2 per day (effective full sun hours)
Required array current 28.95A (total/insolation)
Numbe of panels 28.95/2.94 --> 9.85 --> 10 panels
-----------------------------------
Nothing in there about batteries.
Nothing in there about using your spreadsheet or any of your calculations.
--ron
bea...@gmail.com
Oh look, Tweedledum is back with more of the same. All words, no
maths. How predictable.
bea...@gmail.com
Ok, let's look at a system to run 2500Watts of pump for 30 Minutes.
Tweedledee has proposed a system without batteries.
This is the proposal;
---------------------
AC Load 2500W x 0.5hrs/day --> 1250 watt-hrs/day
Inverter Efficiency 85%
Adjusted AC Load 1471 Watt-hrs/day
Nominal system voltage 12V (This is appropriate for your panels)
Total load in AH 123 amp-hrs per day
System Losses, etc 20%
Total Required 147 amp-hrs per day
Worst month insolation 5.08 kWh/m^2 per day (effective full sun
hours)
Required array current 28.95A (total/insolation)
Numbe of panels 28.95/2.94 --> 9.85 --> 10 panels
-----------------------------------
Simple enough, but then Tweedledee is pretty simple.
First is 1250 Watt hours a day @ 230 Volts AC {This is actually
2941.18 Watts that the inverter is drawing}
The inverter is 85% efficient so we adjust the Whs to 1471Whs {2941.14
Watts}
Nominal system voltage 12V {keep this in mind}
Total load in AH 123 amp-hrs per day {245.1 Amps}
System Losses, etc 20%
Total Required 147 amp-hrs per day {At 12V = 294.12 Amps}
Worst month insolation 5.08 kWh/m^2 per day (effective full sun
hours)
Required array current 28.95A (total/insolation) {Will produce 147.07
Ahs at 12 Volts over 5.08 hours the pump is required to run for half
an hour}
Numbe of panels 28.95/2.94 --> 9.85 --> 10 panels
BUT, the pump requires 2500 Watts to run (2500 Watts / 12V = 208.33
Amps) and something like five times that to start (1041.65 Amps)and
this doesn't even take into account the inverters efficiency.
No matter how you slice it 28.95 amps at 12 volts ain't gonna run that
pump.
Without batteries, Tweedledee's proposal is pure nonsense.
Now Tweedledee will say that of course there are batteries.
BUT, if there are batteries they must be part of the calculation.
Tweedledee is up to his ass in shit and sinking fast.
bea...@gmail.com
The battery size given in the calculation is the minimum capacity
required to run the stated pump for 30 minutes. The calculation allows
you the choose a battery.
Ron Rosenfeld
I see you are blathering again, George.
You clearly are not interested in having any kind of serious conversation.
You are more interested in parsing out bits and pieces of what has been
written so you can engage in some uncreative name-calling.
You obviously didn't understand why I asked the OP about methods and the
need for energy storage, as compared with your recommendation of a 154
panel system.
--ron
bea...@gmail.com
> --ron
As you wished, no batteries, no spreadsheet. Using your calculations.
So predictable. Tell us how 29 Amps of panels at 12 Volts is going to
run a pump that requires 2500 Watts at 230 Volts without batteries.
Because that's what you said. You can't get much more serious than
that.
Perhaps you now want to add the batteries to the equation now.
Ron Rosenfeld
It seems you will not (or cannot) specify a practical battery to use in
this application that matches the inputs you used in your spreadsheet.
I must say that doesn't surprise me, although I was hopeful of finding a
battery with a 90% efficiency, a flat current vs capacity curve in the 30
min to 100 hr range, along with an acceptable life when limited to 70%
maximum DOD.
If your system is going to work, your 180Ah capacity battery at the 100 hr
rate -- 1.8A, must also have the *same* capacity when putting out 245A for
the 1/2 hour that the pump will be running!
C'mon George, what kind of a battery is this? If you can't supply the
battery you specified, your system is pretty worthless.
--ron
bea...@gmail.com
As I have already pointed out it is a recommendation for minimum
battery capacity and not a recommendation for a particular battery.
But as you asked, the total removed from the battery would be 122.5Ah
from 180Ah storage in half an hour. Which is as close as you can get
with only the recommendation for minimum battery capacity.
On the other hand "YOU" have recommended a very definite 28 Amps of 12
Volt panels to run a 230 Volt, 2500 Watt pump and specified no
batteries and no spreadsheet. As you do not want the batteries or the
spreadsheet why do you keep harping back to them?
This is your second post in a day where you have failed to answer the
question of how 10 panels at 28 Amps total will run 2500 Watts of pump
without batteries.
Why is no one surprised?
Ron Rosenfeld
>This is your second post in a day where you have failed to answer the
>question of how 10 panels at 28 Amps total will run 2500 Watts of pump
>without batteries.
*I* never claimed that it would. Your "straw-man" technique of debating is
pretty transparent, George.
You, on the other hand, have posed at least three systems which you claim
would work -- but none of them will work reliably 24/7.
--ron
Ron Rosenfeld
>As I have already pointed out it is a recommendation for minimum
>battery capacity and not a recommendation for a particular battery.
>
>But as you asked, the total removed from the battery would be 122.5Ah
>from 180Ah storage in half an hour. Which is as close as you can get
>with only the recommendation for minimum battery capacity.
Yes, but you have failed to recommend a battery that meets the
specifications that you put into your useless spreadsheet.
In your useless spreadsheet, you specified a minimum battery capacity of
180Ah at the 100 hr rate. Now you are writing that this battery will also
have a capacity of 180Ah at the 30 minute rate.
But you remain unwilling to specify a real world battery that would have
those characteristics, along with the 90% efficiency and 30% maximum DOD
that you also specified in your useless spreadsheet.
Did you just make up some imaginary battery specifications, George, or do
you really know of a battery that has the same capacity at its 100hr rate
as it does at its 30 minute rate, along with a 90% efficiency and a 30%
maximum DOD?
For those who might be following along but not cognizant of battery
characteristics, the problem here is that the usual lead-acid battery may
have a capacity, at its 30 minute rate, of maybe 20% of the capacity at the
100 hr rate. Since George is specifying a battery in his spreadsheet that
has a capacity of 180Ah at the 100 hr rate, its capacity at the rate that
must be used in this system is only going to be maybe 35Ah.
*Unless* there is something special about the battery which George is
unwilling to disclose.
Clearly, George, your knowledge of battery current vs capacity curves is
fairly limited. But you could probably research Peukert for some
information about this factor.
Here's what you entered into your useless spreadsheet, with regard to the
battery you are recommending for this system:
B1 Number of days of autonomy = 1
B2 Maximum allowable depth of discharge = 70%
B6 Adjusted battery capacity (B3 / B5) = 180.5
B7 Selected Battery
B8 Selected battery discharge rate 100
B9 A-hr capacity of selected battery = 180Ah
B10 Number of batteries in parallel (B6 / B9, rounded off) = 1
B11 Number of batteries in series (A7 / battery voltage) =1
B12 Check Capacity of selected battery at l00 Hr rate = 180
B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 180
B14 Daily depth of discharge (100 x A8 / B13) = 68%
C4 Battery efficiency = 90%
So far, you've made a number of errors in trying to design for the OP's
system, even with your last attempt.
1. You specified your battery incorrectly, specifying a 100 hr rate to
determine the capacity instead of the 30 minute rate which you should have
been using.
Although your message above seems to indicate that you finally understand
that, you show no evidence of understanding that a battery with a 180Ah
capacity at the 30 minute rate might have as much as a 1200 Ah
capacity at the 100 hr rate you entered into your useless spreadsheet.
And you have been unable to specify a real battery that does have the
characteristics of the one you entered.
2. You have assumed that 1 day of autonomy will be sufficient at the OP's
location.
3. You have assumed that the OP requires battery storage.
4. You have accused me of oversizing the array, when, even your last
attempt, is for a system that includes 11 panels vs the 10 panels I
recommended.
5. You have attempted to shoehorn my recommnedation for array sizing into
your useless spreadsheet in an attempt to convince yourself that my panel
array size recommendation somehow means an inappropriate battery size. And
even there, you still used the same, incorrect, 100 hr capacity figure.
6. You have used an inappropriate daily temperature figure for the
OP's location.
> B4 Lowest 24 hour average temperature =15c
7. You seem to have specified the OP's panel incorrectly
OP: Assume for instance the panels are 50 watt, 17 vdc, 2.94 amp
So GG enters into his spreadsheet:
C8 Selected module I at 14 volts at NOCT 2.94A
which equates to about a 41 watt panel. You then apply various corrections
to this number, to further reduce its output.
You've been at this game long enough that you should have learned how not
to make these simple errors, or to correct them promptly if you do.
It is sad, but clearly you have not advanced since 1999 when Nick Pine
wrote about you: "Who would hire this PV nitwit?"
--ron
--ron
bea...@gmail.com
> On Wed, 9 Jul 2008 20:53:42 -0700 (PDT), beal...@gmail.com wrote:
> >As I have already pointed out it is a recommendation for minimum
> >battery capacity and not a recommendation for a particular battery.
>
> >But as you asked, the total removed from the battery would be 122.5Ah
> >from 180Ah storage in half an hour. Which is as close as you can get
> >with only the recommendation for minimum battery capacity.
>
> Yes, but you have failed to recommend a battery that meets the
> specifications that you put into your useless spreadsheet.
No, not failed. 180Ah is the correct minimum required. The actual
battery to be chosen. You clearly stated that you didn't want a
battery included so why are you crying now?
>
> In your useless spreadsheet, you specified a minimum battery capacity of
> 180Ah at the 100 hr rate. Now you are writing that this battery will also
> have a capacity of 180Ah at the 30 minute rate.
No. 180AH is the correct minimum required. This minimum must be met or
exceeded by the actual battery chosen with the chosen batteries
parameters entered.
>
> But you remain unwilling to specify a real world battery that would have
> those characteristics, along with the 90% efficiency and 30% maximum DOD
> that you also specified in your useless spreadsheet.
Lying about the numbers is the hallmark of a shyster. The Maximum DOD
is clearly stated as 70%. This leaves 30% remaining in the battery.
>
> Did you just make up some imaginary battery specifications, George, or do
> you really know of a battery that has the same capacity at its 100hr rate
> as it does at its 30 minute rate, along with a 90% efficiency and a 30%
> maximum DOD?
Lying about the numbers is the hallmark of a shyster. The Maximum DOD
is clearly stated as 70%. This leaves 30% remaining in the battery.
>
> For those who might be following along but not cognizant of battery
> characteristics, the problem here is that the usual lead-acid battery may
> have a capacity, at its 30 minute rate, of maybe 20% of the capacity at the
> 100 hr rate. Since George is specifying a battery in his spreadsheet that
> has a capacity of 180Ah at the 100 hr rate, its capacity at the rate that
> must be used in this system is only going to be maybe 35Ah.
George did not at any point recommend a battery. In fact Tweedledee is
the only one to recommend a battery, T105 Trojan.
>
> *Unless* there is something special about the battery which George is
> unwilling to disclose.
>
> Clearly, George, your knowledge of battery current vs capacity curves is
> fairly limited. But you could probably research Peukert for some
> information about this factor.
>
> Here's what you entered into your useless spreadsheet, with regard to the
> battery you are recommending for this system:
>
> B1 Number of days of autonomy = 1
> B2 Maximum allowable depth of discharge = 70%
>
> B6 Adjusted battery capacity (B3 / B5) = 180.5
>
> B7 Selected Battery
It will be noted that B7 is blank. This is because I have not
recommended a battery.
> B8 Selected battery discharge rate 100
B8 requires information from user about chosen battery
> B9 A-hr capacity of selected battery = 180Ah
B8 requires information from user about chosen battery
> B10 Number of batteries in parallel (B6 / B9, rounded off) = 1
> B11 Number of batteries in series (A7 / battery voltage) =1
> B12 Check Capacity of selected battery at l00 Hr rate = 180
> B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 180
> B14 Daily depth of discharge (100 x A8 / B13) = 68%
>
> C4 Battery efficiency = 90%
>
> So far, you've made a number of errors in trying to design for the OP's
> system, even with your last attempt.
This is the correct formula for the sizing of standalone PV systems.
It requires user input.
>
> 1. You specified your battery incorrectly, specifying a 100 hr rate to
> determine the capacity instead of the 30 minute rate which you should have
> been using.
User input required.
>
> Although your message above seems to indicate that you finally understand
> that, you show no evidence of understanding that a battery with a 180Ah
> capacity at the 30 minute rate might have as much as a 1200 Ah
> capacity at the 100 hr rate you entered into your useless spreadsheet.
180 Ah is the minimum required.
>
> And you have been unable to specify a real battery that does have the
> characteristics of the one you entered.
I have not specified a battery.
>
> 2. You have assumed that 1 day of autonomy will be sufficient at the OP's
> location.
Oh dear. you need to learn that when you are up to your ass in shit
and sinking fast you should not put your foot in your mouth.
I in fact am on record as saying:
Of course there is still the problem of designing for an autonomy of
only one day. It is more common to design for several days autonomy.
So let's up the ante and change the system for 5 days autonomy. We
will keep the Trojans so we can clearly see the change;
A2 Daily load = 1250Wh
A4 Inverter Efficiency = 85%
A5 Account for inverter inefficiency - Load (A2/A4) = 1470.5
A7 System Voltage = 12
A8 Total A-hr demand per day (A5 / A7) = 122.55
B1 Number of days of autonomy = 5
B2 Maximum allowable depth of discharge = 70%
B3 Battery capacity (A8 x B1 / B2) = 875.35Ah
B4 Lowest 24 hour average temperature =15c
B5 Temperature correction factor =.97
B6 Adjusted battery capacity (B3 / B5) = 902.42
B7 Selected Battery
B8 Selected battery discharge rate 100
B9 A-hr capacity of selected battery = 225Ah
B10 Number of batteries in parallel (B6 / B9, rounded off) = 4
B11 Number of batteries in series (A7 / battery voltage) =1
B12 Check Capacity of selected battery at l00 Hr rate = 225
B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 900
B14 Daily depth of discharge (100 x A8 / B13) = 13.62%
C1 Design tilt
C2 Design month
C3 Total energy demand per day (A8) =122.55Ah
C4 Battery efficiency = 90%
C5 Array output required per day (C3 / C4) = 136.2
C6 Peak sun hours at design tilt for design month = 5
C7 Selected module
C8 Selected module I at 14 volts at NOCT 2.94A
C9 Selected module nominal operating voltage. = 12V
C10 Guaranteed current (C8 x 0.9) = 2.65A
C11 Number of modules in series (A7 / C9) = 1
C12 Output per module (C10 x C6) = 13.2Ah
C13 Number of parallel strings of modules (C5 / C12) = 10.3
>
> 3. You have assumed that the OP requires battery storage.
Ah yes. 28 Amps of panels at 12 volts to run a 2500 Watt pump at
230Volts without batteries. Why don't you explain how this works.
>
> 4. You have accused me of oversizing the array, when, even your last
> attempt, is for a system that includes 11 panels vs the 10 panels I
> recommended.
>
> 5. You have attempted to shoehorn my recommnedation for array sizing into
> your useless spreadsheet in an attempt to convince yourself that my panel
> array size recommendation somehow means an inappropriate battery size. And
> even there, you still used the same, incorrect, 100 hr capacity figure.
>
> 6. You have used an inappropriate daily temperature figure for the
> OP's location.
>
> > B4 Lowest 24 hour average temperature =15c
>
> 7. You seem to have specified the OP's panel incorrectly
>
> OP: Assume for instance the panels are 50 watt, 17 vdc, 2.94 amp
>
> So GG enters into his spreadsheet:
> C8 Selected module I at 14 volts at NOCT 2.94A
Which is the correct information.
>
> which equates to about a 41 watt panel. You then apply various corrections
> to this number, to further reduce its output.
>
> You've been at this game long enough that you should have learned how not
> to make these simple errors, or to correct them promptly if you do.
>
> It is sad, but clearly you have not advanced since 1999 when Nick Pine
> wrote about you: "Who would hire this PV nitwit?"
Ah yes, good old nick. The man who can barly get his porch light to
work on solar, the inventor of the solar garage. How many of those do
you think he has sold?
> --ron
> --ron
Tweedledee said:
> AC Load 2500W x 0.5hrs/day --> 1250 watt-hrs/day
> Inverter Efficiency 85%
> Adjusted AC Load 1471 Watt-hrs/day
> Nominal system voltage 12V (This is appropriate for your panels)
> Total load in AH 123 amp-hrs per day
> System Losses, etc 20%
> Total Required 147 amp-hrs per day
> Worst month insolation 5.08 kWh/m^2 per day (effective full sun hours)
> Required array current 28.95A (total/insolation)
> Numbe of panels 28.95/2.94 --> 9.85 --> 10 panels
-----------------------------------
And he is very adamant about;
> Nothing in there about batteries.
> Nothing in there about using your spreadsheet or any of your calculations.
So no batteries, no spreadsheet. And 28 Amps of panels at 12 Volts
will not run a 2500 Watt - 230 Volt pump.
All of a sudden Tweedledee wants to talk about Batteries and
Spreadsheets, funny that.
Ron Rosenfeld
>> But you remain unwilling to specify a real world battery that would have
>> those characteristics, along with the 90% efficiency and 30% maximum DOD
>> that you also specified in your useless spreadsheet.
>
>Lying about the numbers is the hallmark of a shyster. The Maximum DOD
>is clearly stated as 70%. This leaves 30% remaining in the battery.
You're correct George. I made a typo in quoting your data. I wrote 30%
maximum DOD when I should have written 30% SOC or 70% DOD.
But you still can't specify a battery that meets *your* specifications of
180Ah at 100 hr rate
90% efficiency
70% maximum DOD
and will also have a capacity of 180Ah at its 30 minute rate.
You can make up imaginary specifications all you want, but if you can't
produce a battery that meets them, or even comes close, your specifications
are useless.
You probably don't realize that a battery with a 180Ah capacity at its 100
hr rate, as you specify in your useless spreadsheet, will have a *much*
lower capacity at its 30 minute rate.
And you can't even read, comprehend, or debate intelligently. Your tactic
of taking phrases out of context, deliberately misunderstanding what was
written, name-calling, false attributions, and the like, of which you are
guilty, are the true signs of a shyster: "A person who gets along by
petty, sharp practices".
Thanks for the entertainment, George. But I'm tired of dealing with your
name-calling and childish techniques.
By the way, I think your final attempt of 11 panels and 8 T105 batteries
should work at the OP's location. (The T105 is a 6V battery, so I adjusted
your calculation accordingly).
Of course, a system of 10 panels and 4 T105's would also work, with a
minimum SOC of 40% during the winter months, and no less than 50% the rest
of the year. So your system would have 10% more panels and twice as many
batteries as is necessary to run this system using battery storage with a
goal of no energy shortfall.
One could use more expensive batteries to reduce the number of strings from
your 4 or my 2 to just one, but you'd have to look closely at the
trade-offs, both economic and in maintenance.
--ron
bea...@gmail.com
> On Fri, 11 Jul 2008 17:33:53 -0700 (PDT), beal...@gmail.com wrote:
> >> But you remain unwilling to specify a real world battery that would have
> >> those characteristics, along with the 90% efficiency and 30% maximum DOD
> >> that you also specified in your useless spreadsheet.
>
> >Lying about the numbers is the hallmark of a shyster. The Maximum DOD
> >is clearly stated as 70%. This leaves 30% remaining in the battery.
>
> You're correct George. I made a typo in quoting your data. I wrote 30%
> maximum DOD when I should have written 30% SOC or 70% DOD.
>
> But you still can't specify a battery that meets *your* specifications of
>
> 180Ah at 100 hr rate
> 90% efficiency
> 70% maximum DOD
> and will also have a capacity of 180Ah at its 30 minute rate.
Sigh, The battery capacity is the minimum required. I have not
specified a battery. If you require the 30 minute rate then the chosen
battery will need a minimum of 180Ahs capacity at the 30 minute rate.
The formula requires this information from the user for the users
chosen battery. The formula is correct.
>
> You can make up imaginary specifications all you want, but if you can't
> produce a battery that meets them, or even comes close, your specifications
> are useless.
I have not made up any specifications. I have not specified a battery.
>
> You probably don't realize that a battery with a 180Ah capacity at its 100
> hr rate, as you specify in your useless spreadsheet, will have a *much*
> lower capacity at its 30 minute rate.
The 180 Ah capacity is the minimum required, not a battery
recommendation.
>
> And you can't even read, comprehend, or debate intelligently. Your tactic
> of taking phrases out of context, deliberately misunderstanding what was
> written, name-calling, false attributions, and the like, of which you are
> guilty, are the true signs of a shyster: "A person who gets along by
> petty, sharp practices".
The formula is correct.
>
> Thanks for the entertainment, George. But I'm tired of dealing with your
> name-calling and childish techniques.
>
> By the way, I think your final attempt of 11 panels and 8 T105 batteries
> should work at the OP's location. (The T105 is a 6V battery, so I adjusted
> your calculation accordingly).
>
> Of course, a system of 10 panels and 4 T105's would also work, with a
> minimum SOC of 40% during the winter months, and no less than 50% the rest
> of the year. So your system would have 10% more panels and twice as many
> batteries as is necessary to run this system using battery storage with a
> goal of no energy shortfall.
>
> One could use more expensive batteries to reduce the number of strings from
> your 4 or my 2 to just one, but you'd have to look closely at the
> trade-offs, both economic and in maintenance.
> --ron
The formula is correct. It requires an amount of user input. Given the
correct input it will correctly size a system.
I presented the formula as it is. If you want to use it feel free, or,
you can have it as a spreadsheet, also free form me at the email
address that can be found in my profile. I am always happy to discuss
system sizing at any time so if you need any help with the formula or
Spreadsheet you can drop me an email.
Neither Tweedledee or Tweedledum have as yet proven the formula to be
incorrect in any way.
Tweedledee has said:
> You, on the other hand, have posed at least three systems which you claim
> would work -- but none of them will work reliably 24/7.
And:
> In your useless spreadsheet, you specified a minimum battery capacity of
> 180Ah at the 100 hr rate. Now you are writing that this battery will also
> have a capacity of 180Ah at the 30 minute rate.
Plain to see that you can't have it both ways 24/7 or 30 minutes.
Use the formula or not. Take a guess or use real numbers. Get it right
or get it wrong.
Totally up to you.
Ron Rosenfeld
>The formula is correct. It requires an amount of user input. Given the
>correct input it will correctly size a system.
The formula may be "correct", but the user inputs you provided with your 5
day of autonomy guesstimate result in a significantly oversized system.
And your sheet has no way of accurately estimating system components and
performance for a particular location.
Your initial 1 day of autonomy was a guess.
Your subsequent 5 days of autonomy is another guess.
Neither are correct for the location and panel array size calculated.
Your specification of 180Ah at the 100 hr rate was wrong.
Your input for panel voltage did not agree with that of the OP's panels.
Your input for ambient temperature was wrong.
Your technique, properly applied, may have been useful years ago, but both
data availability and computer techniques have advanced; allowing better
tailored results.
As you so properly write:
>Take a guess or use real numbers.
You have been taking guesses.
> Get it right or get it wrong.
Many of your inputs have been wrong.
And, although your last system will work, it is significantly oversized,
with more panels and more batteries than would be required at the OP's
location. But this is probably the best you can do with your spreadsheet.
Without doing simulations, though, there is no good way to figure this out.
And since you are the designer, you should not expect the OP to have
knowledge of ten year averages and ranges for solar insolation; required
days of autonomy for his location; temperature ranges, etc. You are the
one that should be supplying this "user input".
Simulations supplied with pricing data can also figure out the most
economic system, and even compare it with grid extension costs and grid
power costs.
--ron
bea...@gmail.com
> On Fri, 11 Jul 2008 21:51:15 -0700 (PDT), beal...@gmail.com wrote:
> >The formula is correct. It requires an amount of user input. Given the
> >correct input it will correctly size a system.
>
> The formula may be "correct", but the user inputs you provided with your 5
> day of autonomy guesstimate result in a significantly oversized system.
Back to the same old same old. All you have to do is prove it, a
single set of calculations.
>
> And your sheet has no way of accurately estimating system components and
> performance for a particular location.
Nonsense
>
> Your initial 1 day of autonomy was a guess.
No
>
> Your subsequent 5 days of autonomy is another guess.
No
>
> Neither are correct for the location and panel array size calculated.
Lie.
>
> Your specification of 180Ah at the 100 hr rate was wrong.
No. The 180Ah is the correct minimum capacity. If you choose a battery
and apply a discharge rate of C 0.5 the minimum capacity is still
180Ah
>
> Your input for panel voltage did not agree with that of the OP's panels.
It was correct.
>
> Your input for ambient temperature was wrong.
I did not provide any information for ambient temperature. I did
provide lowest average temperature
>
> Your technique, properly applied, may have been useful years ago, but both
> data availability and computer techniques have advanced; allowing better
> tailored results.
Show us
>
> As you so properly write:
>
> >Take a guess or use real numbers.
>
> You have been taking guesses.
No
>
> > Get it right or get it wrong.
I'm right, you are wrong
>
> Many of your inputs have been wrong.
No
>
> And, although your last system will work, it is significantly oversized,
> with more panels and more batteries than would be required at the OP's
> location. But this is probably the best you can do with your spreadsheet.
All you have to do is prove it, a single set of calculations.
>
> Without doing simulations, though, there is no good way to figure this out.
> And since you are the designer, you should not expect the OP to have
> knowledge of ten year averages and ranges for solar insolation; required
> days of autonomy for his location; temperature ranges, etc. You are the
> one that should be supplying this "user input".
Why not. All the info can be found on many sites from the local
weather to NASA. All I provided was the formula to do the sizing. It
is correct. There are two ways to get a standalone PV system - 1) Hire
someone to do it for you, in which case you don't need to come here
and ask questions. - 2) Be prepared to learn how to do it for your
self, in which case you need to apply your self to the job and chase
your own information.
>
> Simulations supplied with pricing data can also figure out the most
> economic system, and even compare it with grid extension costs and grid
> power costs.
Yeah, I'll go along with that. Mind you it would be a huge program
having to contain all the worlds suppliers catalogs and price lists
not to mention the complete meteorology of the world as well. Tell you
what, why don't you write it up over the weekend and post it here on
Monday?
If you are not prepared to find the info you need, you are not
prepared to be in control of your own energy supply. The calculation
for system sizing is correct, as long as the info "YOU" put in is
correct.
Now you can tell us how 28 Amps of panels at 12 Volts will run a 230
Volt pump that draws 2500 Watts without batteries.
Oh dear, is that the sound of Running feet?
> --ron
Ron Rosenfeld
>On Jul 12, 10:55 pm, Ron Rosenfeld <ronrosenf...@nospam.org> wrote:
>> On Fri, 11 Jul 2008 21:51:15 -0700 (PDT), beal...@gmail.com wrote:
>> >The formula is correct. It requires an amount of user input. Given the
>> >correct input it will correctly size a system.
>>
>> The formula may be "correct", but the user inputs you provided with your 5
>> day of autonomy guesstimate result in a significantly oversized system.
>
>Back to the same old same old. All you have to do is prove it, a
>single set of calculations.
>>
>> And your sheet has no way of accurately estimating system components and
>> performance for a particular location.
>
>Nonsense
>>
>> Your initial 1 day of autonomy was a guess.
>
>No
If not a guess, then it was a wrong input.
>>
>> Your subsequent 5 days of autonomy is another guess.
>
>No
>>
>> Neither are correct for the location and panel array size calculated.
>
>Lie.
>>
>> Your specification of 180Ah at the 100 hr rate was wrong.
>
>No. The 180Ah is the correct minimum capacity. If you choose a battery
>and apply a discharge rate of C 0.5 the minimum capacity is still
>180Ah
I see. So you are claiming that when you posted:
B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 180
That we should understand that this is not at the 100 hr rate, but rather
at the 30 minute rate?
Or are you claiming that this battery has the same capacity at the 100 hr
rate vs the 30 minute rate?
>>
>> Your input for panel voltage did not agree with that of the OP's panels.
>
>It was correct.
Could you explain then, the difference between your 14V input and the OP's
17V panels?
OP: the panels are 50 watt, 17 vdc, 2.94 amp
GG: C8 Selected module I at 14 volts at NOCT 2.94A
>>
>> Your input for ambient temperature was wrong.
>
>I did not provide any information for ambient temperature. I did
>provide lowest average temperature
It was still wrong. The lowest average temperature for that area is
21.5°C; the lowest average daily low temperature is about 17.5°C
>>
>> Your technique, properly applied, may have been useful years ago, but both
>> data availability and computer techniques have advanced; allowing better
>> tailored results.
>
>Show us
>>
>> As you so properly write:
>>
>> >Take a guess or use real numbers.
>>
>> You have been taking guesses.
>
>No
>>
>> > Get it right or get it wrong.
>
>I'm right, you are wrong
>>
>> Many of your inputs have been wrong.
>
>No
>>
>> And, although your last system will work, it is significantly oversized,
>> with more panels and more batteries than would be required at the OP's
>> location. But this is probably the best you can do with your spreadsheet.
>
>All you have to do is prove it, a single set of calculations.
see below
>If you are not prepared to find the info you need, you are not
>prepared to be in control of your own energy supply. The calculation
>for system sizing is correct, as long as the info "YOU" put in is
>correct.
I'm going to respond to this in a separate message, since it deserves more
comment.
>
>Now you can tell us how 28 Amps of panels at 12 Volts will run a 230
>Volt pump that draws 2500 Watts without batteries.
>
I never said it would. You are the only one making that preposterous
claim. I stated that energy storage would be required. I can't help it if
your application of your spreadsheet to my data came up with a wrong
result.
--ron
Ron Rosenfeld
>If you are not prepared to find the info you need, you are not
>prepared to be in control of your own energy supply. The calculation
>for system sizing is correct, as long as the info "YOU" put in is
>correct.
Here we are. The bottom line:
George Ghio, the "system designer" expects "you" to find the data needed.
In other words, George won't supply it, and if you can't do it yourself,
don't call him!
(If you can do it yourself, you wouldn't want to call him either).
--ron
bea...@gmail.com
Truth is that anybody can reach me at the email address under my
profile. I am prepared to help those that are prepared to help
themselves. I will supply a spread sheet and back it up with free help
with any aspect of sizing via email. The best way to learn is to do. I
will help anyone to do it, I will not do the work for someone.
The formula is correct.
bea...@gmail.com
180Ah is the minimum required capacity for the job. IF the system is
expected to use the C0.5 rate or a C120 rate the minimum battery
capacity for the same load will still be 180Ahs
>
> That we should understand that this is not at the 100 hr rate, but rather
> at the 30 minute rate?
You must understand that this is user input and will be for the
battery you choose.
>
> Or are you claiming that this battery has the same capacity at the 100 hr
> rate vs the 30 minute rate?
No. This come from your ability to understand user input.
>
>
>
> >> Your input for panel voltage did not agree with that of the OP's panels.
>
> >It was correct.
>
> Could you explain then, the difference between your 14V input and the OP's
> 17V panels?
>
> OP: the panels are 50 watt, 17 vdc, 2.94 amp
>
> GG: C8 Selected module I at 14 volts at NOCT 2.94A
14 volts is the test standard at 25C. 17 volts is what the produces
when not connected to a load. Surprised you don't know this.
>
>
>
> >> Your input for ambient temperature was wrong.
>
> >I did not provide any information for ambient temperature. I did
> >provide lowest average temperature
>
> It was still wrong. The lowest average temperature for that area is
> 21.5°C; the lowest average daily low temperature is about 17.5°C
Oh, I see. As we are talking here about the lowest average daily
temperature the difference between 15C and 17.5C is not going to make
much difference and is in fact around 3Ahs
>
>
>
>
>
> >> Your technique, properly applied, may have been useful years ago, but both
> >> data availability and computer techniques have advanced; allowing better
> >> tailored results.
>
> >Show us
>
> >> As you so properly write:
>
> >> >Take a guess or use real numbers.
>
> >> You have been taking guesses.
>
> >No
>
> >> > Get it right or get it wrong.
>
> >I'm right, you are wrong
>
> >> Many of your inputs have been wrong.
>
> >No
>
> >> And, although your last system will work, it is significantly oversized,
> >> with more panels and more batteries than would be required at the OP's
> >> location. But this is probably the best you can do with your spreadsheet.
>
> >All you have to do is prove it, a single set of calculations.
>
> see below
Below is empty
>
> >If you are not prepared to find the info you need, you are not
> >prepared to be in control of your own energy supply. The calculation
> >for system sizing is correct, as long as the info "YOU" put in is
> >correct.
>
> I'm going to respond to this in a separate message, since it deserves more
> comment.
>
>
>
> >Now you can tell us how 28 Amps of panels at 12 Volts will run a 230
> >Volt pump that draws 2500 Watts without batteries.
>
> I never said it would. You are the only one making that preposterous
> claim. I stated that energy storage would be required. I can't help it if
> your application of your spreadsheet to my data came up with a wrong
> result
>
> --ron
Here we are at the "Below" and not a single calculation in sight.
wmbjk...@citlink.net
<ronros...@nospam.org> wrote:
>On Fri, 11 Jul 2008 21:51:15 -0700 (PDT), bea...@gmail.com wrote:
>The formula may be "correct", but the user inputs you provided with your 5
>day of autonomy guesstimate result in a significantly oversized system.
As is his habit, although in his defense he claims that over-sizing
allows for such things as "unexpected babies". :-)
>And your sheet has no way of accurately estimating system components and
>performance for a particular location.
>
>Your initial 1 day of autonomy was a guess.
>
>Your subsequent 5 days of autonomy is another guess.
>
> Neither are correct for the location and panel array size calculated.
>
>Your specification of 180Ah at the 100 hr rate was wrong.
>
>Your input for panel voltage did not agree with that of the OP's panels.
>
>Your input for ambient temperature was wrong.
>
>Your technique, properly applied, may have been useful years ago, but both
>data availability and computer techniques have advanced; allowing better
>tailored results.
He's just a little behind the times. For example, Peukert's Law was
presented in 1897, but George simply ignores it, even when discussing
high-current loads. Like many of his other mistakes, it's rooted in
his lack of experience. He has no more idea about high-current loads
than he does about battery monitors, energy meters, inverter-chargers,
or MPPT controllers. Most are able to learn about things they don't
have any personal experience with, but George prefers to pretend that
whatever he can't afford or has never seen must be unnecessary,
wasteful, foolish choices of "yanks", etc.
>As you so properly write:
>
>>Take a guess or use real numbers.
>
>You have been taking guesses.
>
>> Get it right or get it wrong.
>
>Many of your inputs have been wrong.
>
>And, although your last system will work, it is significantly oversized,
>with more panels and more batteries than would be required at the OP's
>location. But this is probably the best you can do with your spreadsheet.
>
>Without doing simulations, though, there is no good way to figure this out.
>And since you are the designer, you should not expect the OP to have
>knowledge of ten year averages and ranges for solar insolation; required
>days of autonomy for his location; temperature ranges, etc. You are the
>one that should be supplying this "user input".
>
>Simulations supplied with pricing data can also figure out the most
>economic system, and even compare it with grid extension costs and grid
>power costs.
That's just another thing he prefers to ignore. Posters have been
supplying links to PVWatts and HOMER for years, but you'll never see
the ghinius recommend those. He prefers to pretend that a GIGO
spreadsheet is best for every need.
Wayne
wmbjk...@citlink.net
>On Jul 13, 4:23 am, Ron Rosenfeld <ronrosenf...@nospam.org> wrote:
>> Here we are. The bottom line:
>>
>> George Ghio, the "system designer" expects "you" to find the data needed.
>>
>> In other words, George won't supply it, and if you can't do it yourself,
>> don't call him!
>>
>> (If you can do it yourself, you wouldn't want to call him either).
>> --ron
>
> The best way to learn is to do.
Yes, but there are so many things you've never done, and therefore
have never learned about. Which is why you've tried to scare readers
away from using KillaWatts to name just one dopey result. Why not get
one (the Oz equivalent), so that you can finally start learning
something useful, and join in the discussion based on experience
rather than on idiotic and contrary opinions?
Wayne
bea...@gmail.com
Lying again eh. I have nothing against watt metres, only fools who use
them for a party trick, claim to own two and still cant tell us what
his system uses or produces.
He also says that you can reduce voltage drop by increasing the load.
Goodby fool.
bea...@gmail.com
> On Sat, 12 Jul 2008 08:55:26 -0400, Ron Rosenfeld
>
Tell us about your system. What are the loads? How long are they run
and what they draw. While you are at it you can explain how increasing
the load reduces line losses (Voltage Drop)
bea...@gmail.com
There are many things I have not done. This is of course true for all
of us. Some of the more notable things I have not done are:
1) I have never copied a system from a magazine and claimed that I
designed it. wayne has.
2) I have never copied a system from a magazine, found it did not meet
my needs and kept throwing money at it until it at least worked during
daylight hours. wayne has.
3) I have never hired a bunch of contractors to build my house then
claimed that I built the house. wayne has.
4) I have never have never claimed to be the "General Contractor" and
blamed the subbies for failings of the "General Contractor". wayne
has.
5) I have never taken an argument away form these groups or set up a
web site to harass someone. wayne has.
6) I have never stalked a person across the internet. wayne has.
7) I have never claimed that you can reduce line losses (Voltage Drop)
by by increasing the load. wayne has.
My goodness, what a dull life I lead.
OTOH I have designed and built dozens of systems, all of which worked
to spec from the moment they were turned on.
All of these systems were sized with the formula that has been
presented here. It works. It is correct. It is free, as is the
spreadsheet and backup via email.
Tweedledee and Tweedledum have yet to prove that the formula is
incorrect, and that will never happen.
wmbjk...@citlink.net
>On Jul 13, 10:47 am, wmbjkREM...@citlink.net wrote:
>> On Sat, 12 Jul 2008 17:21:30 -0700 (PDT), beal...@gmail.com wrote:
>> >On Jul 13, 4:23 am, Ron Rosenfeld <ronrosenf...@nospam.org> wrote:
>> >> Here we are. The bottom line:
>>
>> >> George Ghio, the "system designer" expects "you" to find the data needed.
>>
>> >> In other words, George won't supply it, and if you can't do it yourself,
>> >> don't call him!
>>
>> >> (If you can do it yourself, you wouldn't want to call him either).
>> >> --ron
>>
>> > The best way to learn is to do.
>>
>> Yes, but there are so many things you've never done, and therefore
>> have never learned about. Which is why you've tried to scare readers
>> away from using KillaWatts to name just one dopey result. Why not get
>> one (the Oz equivalent), so that you can finally start learning
>> something useful, and join in the discussion based on experience
>> rather than on idiotic and contrary opinions?
>>
>> Wayne
>
>Lying again eh.
Does that mean that you're now claiming some experience with
KillaWatts? Or would it be more fair to assume that you're an alleged
professional who can't afford a $20 tool?
> I have nothing against watt metres, only fools who use
>them for a party trick
No, in fact, you've written dozens of posts trying to convince readers
that appliance labels contain everything they need to know about
energy consumption. If you had the experience of actually using a watt
meter to measure a variable load, then you'd recognize the foolishness
of your premise. It's clear that you have no intention of gaining that
experience, or of learning from the experience of others.
>He also says that you can reduce voltage drop by increasing the load.
No, that's just another of your pointless whoppers.
>Goodby fool.
Perhaps you mean "goodbye, fool", eh, Mr. Edator?
Wayne
Ron Rosenfeld
>> GG: C8 Selected module I at 14 volts at NOCT 2.94A
>
>14 volts is the test standard at 25C. 17 volts is what the produces
>when not connected to a load. Surprised you don't know this.
No, I was not aware of a test standard that specified a particular voltage
for the PV cell.
What standard is that?
The standards I've seen with regard to PV panels are STC and PTC.
But they both refer to wattage ratings under specified conditions of
irradiance, temperature and, for the PTC standard, wind speed. Neither one
mentions a particular voltage.
NOCT is not mentioned in either of those standards, and the irradiance used
to determine NOCT is not the same as that used in either STC or PTC
standards.
--ron
bea...@gmail.com
Tweedlwdum's wisdom; On Jun 23, alt.solar.photovoltaic,
wmbjkREM...@citlink.net wrote: alt.solar.photovoltaic
> No, it doesn't. A quicky estimating shortcut is to allow for one-third
> total losses from nameplate PV rating to account for inefficiencies
> for non MPPT, inverter, battery and wiring losses.
That's right "wiring losses"
Wiring losses are the result of the resistance of a conductor. The
loss is referred to as "voltage drop". Increasing the load increases
the voltage drop.
Tweedledum is as ignorant as Tweedledee.
The formula covers all losses with out having to add a spurious 20%
loss anywhere.
bea...@gmail.com
Ron Rosenfeld
>A2 Daily load = 1250Wh
>A4 Inverter Efficiency = 85%
>A5 Account for inverter inefficiency - Load (A2/A4) = 1470.5
>A7 System Voltage = 12
>A8 Total A-hr demand per day (A5 / A7) = 122.55
>
>B1 Number of days of autonomy = 1
>B2 Maximum allowable depth of discharge = 70%
>B3 Battery capacity (A8 x B1 / B2) = 175Ah
>B4 Lowest 24 hour average temperature =15c
>B5 Temperature correction factor =.97
>B6 Adjusted battery capacity (B3 / B5) = 180.5
>B7 Selected Battery
>B8 Selected battery discharge rate 100
>B9 A-hr capacity of selected battery = 225Ah
>B10 Number of batteries in parallel (B6 / B9, rounded off) = 1
>B11 Number of batteries in series (A7 / battery voltage) =1
>B12 Check Capacity of selected battery at l00 Hr rate = 225
>B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 225
>B14 Daily depth of discharge (100 x A8 / B13) = 54.47%
>
>C1 Design tilt
>C2 Design month
>C3 Total energy demand per day (A8) =122.55Ah
>C4 Battery efficiency = 90%
>C5 Array output required per day (C3 / C4) = 136.2
>C6 Peak sun hours at design tilt for design month = 5
>C7 Selected module
>C8 Selected module I at 14 volts at NOCT 2.94A
>C9 Selected module nominal operating voltage. = 12V
>C10 Guaranteed current (C8 x 0.9) = 2.65A
>C11 Number of modules in series (A7 / C9) = 1
>C12 Output per module (C10 x C6) = 13.2Ah
>C13 Number of parallel strings of modules (C5 / C12) = 10.3
>
>Prove it wrong.
Let's get back to this challenge of yours, as to whether your
specifications will run the OP's 2500watt pump 1/2 hour per day, every day.
You give incomplete specifications, so it's a tough to run a simulation.
But perhaps, if you can fill in a few details, or agree with some of my
assumptions, we can proceed with a simulation:
With regard to your selected module:
>C8 Selected module I at 14 volts at NOCT 2.94A
Does this mean it has an STC nameplate power rating of 14*2.94 = 41.16
watts? Or is the STC nameplate power rating something else?
>C13 Number of parallel strings of modules (C5 / C12) = 10.3
I will round this up to 11.
Do you want to consider the effect of temperature on the module?
If you do, then we need to use some assumptions about the temperature
coefficient, NOCT and MPPT efficiency at std. test conditions.
I would assume
Temperature coefficient of power = -0.5%/°C
NOCT 45.2°C
MPPT Efficiency at std test cond 13%
but we can use different values if you like, or ignore temperature affects
completely.
With regard to the battery, you have supplied this information:
>B2 Maximum allowable depth of discharge = 70%
>B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 225
>C4 Battery efficiency = 90%
The real world battery I could find (in my database) closest to these
specifications:
Trojan T105
Maximum allowable depth of discharge = 70%
Capacity at 100 hr rate = 240
Efficiency 85%
So I would use two of these in series to provide a 12V battery bank.
Let me know.
--ron
Duane C. Johnson
> 14 volts is the test standard at 25C.
14V is not the test standard at 25C.
Most manufacturers test panels to the ASTM standard
which is at the Maximum Power Point which is usually
around 17 to 18 volts or so and 25C.
> 17 volts is what they produce when not connected
> to a load.
Open circuit voltage of most 12V silicon panels,
with 36 cells, is about 21V. Others may be higher.
> Surprised you don't know this.
Surprised you don't know this.
Duane
--
Home of the $35 Solar Tracker Receiver
http://www.redrok.com/led3xassm.htm [*]
Powered by \ \ \ //|
Thermonuclear Solar Energy from the Sun / |
Energy (the SUN) \ \ \ / / |
Red Rock Energy \ \ / / |
Duane C. Johnson Designer \ \ / \ / |
1825 Florence St Heliostat,Control,& Mounts |
White Bear Lake, Minnesota === \ / \ |
USA 55110-3364 === \ |
(651)426-4766 use Courier New Font \ |
red...@redrok.com (my email: address) \ |
http://www.redrok.com (Web site) ===
wmbjk...@citlink.net
That quote does exactly nothing to prove your straw man claim that I
ever said that "you can reduce voltage drop by increasing the load".
Making things up is called lying.
>Wiring losses are the result of the resistance of a conductor. The
>loss is referred to as "voltage drop". Increasing the load increases
>the voltage drop.
So what? That also does nothing to prove your straw man. In fact,
arguing in circles only advertises your inability to think.
>Tweedledum is as ignorant as Tweedledee.
>
>The formula covers all losses with out having to add a spurious 20%
>loss anywhere.
You might as well say "the sky is blue, therefore anything I write
must be correct".
Wayne
wmbjk...@citlink.net
<red...@redrok.com> wrote:
>bea...@gmail.com wrote:
>
> > 14 volts is the test standard at 25C.
>
>14V is not the test standard at 25C.
>
>Most manufacturers test panels to the ASTM standard
>which is at the Maximum Power Point which is usually
>around 17 to 18 volts or so and 25C.
>
> > 17 volts is what they produce when not connected
> > to a load.
>
>Open circuit voltage of most 12V silicon panels,
>with 36 cells, is about 21V. Others may be higher.
>
> > Surprised you don't know this.
>
>Surprised you don't know this.
You must be the only one. :-) He started off in this thread by
writing (about 50W modules) "14 panels in series to give you 238V @ 3A
> 11 parallel strings to give you 2530A", and his subsequent postings,
intended to distract from the initial mistakes, have only made things
worse. So at this point I for one wouldn't be surprised to see him
wearing his shoes on the wrong feet and calling himself a Bunyin
Cunsultint. :-)
Wayne
bea...@gmail.com
> beal...@gmail.com wrote:
>
> > 14 volts is the test standard at 25C.
>
> 14V is not the test standard at 25C.
>
> Most manufacturers test panels to the ASTM standard
> which is at the Maximum Power Point which is usually
> around 17 to 18 volts or so and 25C.
>
> > 17 volts is what they produce when not connected
> > to a load.
>
> Open circuit voltage of most 12V silicon panels,
> with 36 cells, is about 21V. Others may be higher.
>
> > Surprised you don't know this.
>
> Surprised you don't know this.
Yeah, yeah, yeah. I do know it. But then Tweedledee needs to be kept
busy so I help him achieve busyness. He has learned more about solar
in the last two weeks than he ever learned in the last 10 years.
As you say "17 volts is what they produce when not connected to a
load" which is not what they produce under load. Panels also seldom
operate at 25C or 1000Wm2. More often than not, much hotter and with a
lot less than 1000Wm2.
And unless you want to prove that the formula for system sizing is
incorrect the point has been made.
Thank you for your insight.
George
wmbjk...@citlink.net
>On Jul 14, 9:25 am, "Duane C. Johnson" <red...@redrok.com> wrote:
>> beal...@gmail.com wrote:
>>
>> > 14 volts is the test standard at 25C.
>>
>> 14V is not the test standard at 25C.
>>
>> Most manufacturers test panels to the ASTM standard
>> which is at the Maximum Power Point which is usually
>> around 17 to 18 volts or so and 25C.
>>
>> > 17 volts is what they produce when not connected
>> > to a load.
>>
>> Open circuit voltage of most 12V silicon panels,
>> with 36 cells, is about 21V. Others may be higher.
>>
>> > Surprised you don't know this.
>>
>> Surprised you don't know this.
>
>Yeah, yeah, yeah. I do know it.
If you know this stuff, then why do you constantly need correcting?
>But then Tweedledee needs to be kept
>busy so I help him achieve busyness.
Oh, I see, it's somehow not your fault! What a shocker.
> He has learned more about solar
>in the last two weeks than he ever learned in the last 10 years.
Oh sure, he corrects *your* idiotic 154 panel recommendation, yet it's
he who needs correction. In fact, he's so frequently wrong that there
are 2 web sites making fun of him,
http://www.citlink.net/~wmbjk/tbfduwisdumb.htm and
http://www.lowexpecations.com/. Oh wait, those are about *you*!
>As you say "17 volts is what they produce when not connected to a
>load"
No, that's what *you* wrote, nitwit. Try to keep up, Duane wrote that
"Open circuit voltage of most 12V silicon panels, with 36 cells, is
about 21V. Others may be higher". It appears that you don't know the
difference between MPP and OC, which would explain why you've never
recommended or even mentioned MPPT controllers.
>which is not what they produce under load. Panels also seldom
>operate at 25C or 1000Wm2. More often than not, much hotter and with a
>lot less than 1000Wm2.
So what?
>And unless you want to prove that the formula for system sizing is
>incorrect the point has been made.
The only point that's been made here is that you're not smart enough
to quit foolishly trying to write your way out of holes that you've
written yourself into.
>Thank you for your insight.
Now wait a darned minute! Pretty much everybody here has provided you
more "insight" than Duane. Where is our thanks?
Wayne
bea...@gmail.com
You have the formula, put in your chosen parameters.
>
> With regard to your selected module:
>
> >C8 Selected module I at 14 volts at NOCT 2.94A
If you like, It's closer to the truth than anything you have said
>
> Does this mean it has an STC nameplate power rating of 14*2.94 = 41.16
> watts? Or is the STC nameplate power rating something else?
When was the last time you ever saw a panel of (Enter Number Here)
rated watts produce that rating outside of lab conditions. You name a
temperature and we can use it.
>
> >C13 Number of parallel strings of modules (C5 / C12) = 10.3
>
> I will round this up to 11.
>
> Do you want to consider the effect of temperature on the module?
You name a temperature and we can use it.
>
> If you do, then we need to use some assumptions about the temperature
> coefficient, NOCT and MPPT efficiency at std. test conditions.
Ah. you want to guess.
>
> I would assume
> Temperature coefficient of power = -0.5%/°C
> NOCT 45.2°C
> MPPT Efficiency at std test cond 13%
This is your best guess is it? From the standard test temp of 25C my
checking shows that at 45C:
1) there is an increase of around 1%in the short circuit current
2) A decrease of around 8.5% in the open circuit voltage
3) A decrease of around 6% in the maximum power.
>
> but we can use different values if you like, or ignore temperature affects
> completely.
>
> With regard to the battery, you have supplied this information:
>
> >B2 Maximum allowable depth of discharge = 70%
> >B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 225
> >C4 Battery efficiency = 90%
Ah, no. That was your battery recommendation. If you will remember the
180 Ah was the minimum capacity required. Battery specs to be supplied
by user. You said T105s at 225Ah. Feel free to change this if you
like.
>
> The real world battery I could find (in my database) closest to these
> specifications:
Is this the database that contains T105s and L16s as the worlds supply
of batteries.
>
> Trojan T105
> Maximum allowable depth of discharge = 70%
> Capacity at 100 hr rate = 240
> Efficiency 85%
>
> So I would use two of these in series to provide a 12V battery bank.
>
> Let me know.
You have the formula, go for it
>
> --ron
bea...@gmail.com
> On Sun, 13 Jul 2008 17:21:54 -0700 (PDT), beal...@gmail.com wrote:
> >On Jul 14, 9:25 am, "Duane C. Johnson" <red...@redrok.com> wrote:
> >> beal...@gmail.com wrote:
>
> >> > 14 volts is the test standard at 25C.
>
> >> 14V is not the test standard at 25C.
>
> >> Most manufacturers test panels to the ASTM standard
> >> which is at the Maximum Power Point which is usually
> >> around 17 to 18 volts or so and 25C.
>
> >> > 17 volts is what they produce when not connected
> >> > to a load.
>
> >> Open circuit voltage of most 12V silicon panels,
> >> with 36 cells, is about 21V. Others may be higher.
>
> >> > Surprised you don't know this.
>
> >> Surprised you don't know this.
>
> >Yeah, yeah, yeah. I do know it.
>
> If you know this stuff, then why do you constantly need correcting?
>
> >But then Tweedledee needs to be kept
> >busy so I help him achieve busyness.
>
> Oh, I see, it's somehow not your fault! What a shocker.
>
> > He has learned more about solar
> >in the last two weeks than he ever learned in the last 10 years.
>
> Oh sure, he corrects *your* idiotic 154 panel recommendation, yet it's
> he who needs correction. In fact, he's so frequently wrong that there
>
> >As you say "17 volts is what they produce when not connected to a
> >load"
>
> No, that's what *you* wrote, nitwit. Try to keep up, Duane wrote that
> "Open circuit voltage of most 12V silicon panels, with 36 cells, is
> about 21V. Others may be higher". It appears that you don't know the
> difference between MPP and OC, which would explain why you've never
> recommended or even mentioned MPPT controllers.
>
> >which is not what they produce under load. Panels also seldom
> >operate at 25C or 1000Wm2. More often than not, much hotter and with a
> >lot less than 1000Wm2.
>
> So what?
>
> >And unless you want to prove that the formula for system sizing is
> >incorrect the point has been made.
>
> The only point that's been made here is that you're not smart enough
> to quit foolishly trying to write your way out of holes that you've
> written yourself into.
>
> >Thank you for your insight.
>
> Now wait a darned minute! Pretty much everybody here has provided you
> more "insight" than Duane. Where is our thanks?
>
> Wayne
Tweedledum wants thanks for his bucket of shit. Thank you Tweedledum,
every bit of street Theater needs a clown, keep up the good work.
Ron Rosenfeld
Yes it is sad that you obviously have no idea of the meaning of STC, PTC or
NOCT.
--ron
Ron Rosenfeld
Well, I gave you a serious opportunity to supply some clarification to your
incomplete specifications, so as to run a real-world simulation, and you
clearly are unable to do that.
I'd call that pretty sad for someone who purports to be a solar power
consultant.
--ron
Ron Rosenfeld
It is truly sad that reality does not match George's fantasy.
--ron
bea...@gmail.com
We're still waiting on your all inclusive spread sheet that allows for
all the solar equipment in the world and complete pricing for same.
We are also waiting for yor caluclation for the numbers you proposed
for this post;
From Tweedledee -
Let's get back to this challenge of yours, as to whether your
specifications will run the OP's 2500watt pump 1/2 hour per day, every
day.
You give incomplete specifications, so it's a tough to run a
simulation.
But perhaps, if you can fill in a few details, or agree with some of
my
assumptions, we can proceed with a simulation:
With regard to your selected module:
>C8 Selected module I at 14 volts at NOCT 2.94A
Does this mean it has an STC nameplate power rating of 14*2.94 = 41.16
watts? Or is the STC nameplate power rating something else?
>C13 Number of parallel strings of modules (C5 / C12) = 10.3
I will round this up to 11.
Do you want to consider the effect of temperature on the module?
If you do, then we need to use some assumptions about the temperature
coefficient, NOCT and MPPT efficiency at std. test conditions.
I would assume
Temperature coefficient of power = -0.5%/°C
NOCT 45.2°C
MPPT Efficiency at std test cond 13%
but we can use different values if you like, or ignore temperature
affects
completely.
With regard to the battery, you have supplied this information:
>B2 Maximum allowable depth of discharge = 70%
>B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 225
>C4 Battery efficiency = 90%
The real world battery I could find (in my database) closest to these
specifications:
Trojan T105
Maximum allowable depth of discharge = 70%
Capacity at 100 hr rate = 240
Efficiency 85%
So I would use two of these in series to provide a 12V battery bank.
Well, come on you have the formula, these are the numbers you feel
should be used, show us the calculation.
bea...@gmail.com
Time to look at Tweedledee's claims about;
1) STC - DC watts-The nameplate rating of a solar module.
2) PTC - DC watts-the rating of a module in real-world conditions as
determined by the California Energy Commission.
PTC it seems is not used anywhere other than California to determine
the rebate paid for solar power installations.
Tweedledee left this part of the information out - CEC AC watts - the
total PTC DC of solar modules factoring in inverter efficiency. This
the number that the rebate is based on. This rebate is generally for
"Grid Connect" systems. Not stand alone systems.
But,
Notice where it says "the total PTC DC of solar modules factoring in
inverter efficiency." it looks suspiciously like "A5 & C10" in the
formula, and "STC DC watts-The nameplate rating of a solar module"
bears a striking resemblance to "C8"
A2 Daily load = 1250Wh
A4 Inverter Efficiency = 85%
A5 Account for inverter inefficiency - Load (A2/A4) = 1470.5
A7 System Voltage = 12
A8 Total A-hr demand per day (A5 / A7) = 122.55
B1 Number of days of autonomy = 5
B2 Maximum allowable depth of discharge = 70%
B3 Battery capacity (A8 x B1 / B2) = 875.35Ah
B4 Lowest 24 hour average temperature =15c
B5 Temperature correction factor =.97
B6 Adjusted battery capacity (B3 / B5) = 902.42
B7 Selected Battery
B8 Selected battery discharge rate 100
B9 A-hr capacity of selected battery = 225Ah
B10 Number of batteries in parallel (B6 / B9, rounded off) = 4
B11 Number of batteries in series (A7 / battery voltage) =1
B12 Check Capacity of selected battery at l00 Hr rate = 225
B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 900
B14 Daily depth of discharge (100 x A8 / B13) = 13.62%
C1 Design tilt
C2 Design month
C3 Total energy demand per day (A8) =122.55Ah
C4 Battery efficiency = 90%
C5 Array output required per day (C3 / C4) = 136.2
C6 Peak sun hours at design tilt for design month = 5
C7 Selected module
C8 Selected module I at 14 volts at NOCT 2.94A
C9 Selected module nominal operating voltage. = 12V
C10 Guaranteed current (C8 x 0.9) = 2.65A
C11 Number of modules in series (A7 / C9) = 1
C12 Output per module (C10 x C6) = 13.2Ah
C13 Number of parallel strings of modules (C5 / C12) = 10.3
3) NOCT Normal Operating Cell Temperature. This is "C8" and is user
input from the manufacturer's data.
Oops, Tweedledee has his foot in his mouth again.
Ron Rosenfeld
>> With regard to your selected module:
>>
>> >C8 Selected module I at 14 volts at NOCT 2.94A
>
>If you like, It's closer to the truth than anything you have said
>>
>> Does this mean it has an STC nameplate power rating of 14*2.94 = 41.16
>> watts? Or is the STC nameplate power rating something else?
>
>When was the last time you ever saw a panel of (Enter Number Here)
>rated watts produce that rating outside of lab conditions. You name a
>temperature and we can use it.
>>
>> Do you want to consider the effect of temperature on the module?
>
>You name a temperature and we can use it.
>>
>> If you do, then we need to use some assumptions about the temperature
>> coefficient, NOCT and MPPT efficiency at std. test conditions.
>
>Ah. you want to guess.
>>
>> I would assume
>> Temperature coefficient of power = -0.5%/°C
>> NOCT 45.2°C
>> MPPT Efficiency at std test cond 13%
>
>This is your best guess is it? From the standard test temp of 25C my
>checking shows that at 45C:
>1) there is an increase of around 1%in the short circuit current
>
>2) A decrease of around 8.5% in the open circuit voltage
>
>3) A decrease of around 6% in the maximum power.
This post clearly demonstrates that George doesn't know what NOCT is, even
though he uses it in his useless spreadsheet. He also doesn't know how to
measure or estimate it, nor does he realize the consequences of making
measurements at a test temperature of 25°C vs measurements at a NOCT of
45°C.
--ron
Ron Rosenfeld
Substitute GG for Tweedledee and you've got the right foot in the right
mouth!
GG still has failed to produce any real world items for use, and the
specifications he provides us with continue to need clarification which he
is unable to supply.
He has yet to justify the 14 Volt specification in C8.
He's now bringing in PTC. I'm waiting for him to start talking about the
GTC (Ghinius Test Conditions -- a proprietary and secret method of rating
panels, which no manufacturer uses, but should, if they expect GG to
recommend their products).
--ron
Ron Rosenfeld
>On Jul 15, 6:48 am, Ron Rosenfeld <ronrosenf...@nospam.org> wrote:
>> On Sun, 13 Jul 2008 16:02:23 -0700 (PDT), beal...@gmail.com wrote:
>> >On Jul 14, 8:38 am, Ron Rosenfeld <ronrosenf...@nospam.org> wrote:
>> >> On Sat, 12 Jul 2008 17:21:56 -0700 (PDT), beal...@gmail.com wrote:
>> >> >> GG: C8 Selected module I at 14 volts at NOCT 2.94A
>>
>> >> >14 volts is the test standard at 25C. 17 volts is what the produces
>> >> >when not connected to a load. Surprised you don't know this.
>>
>> >> No, I was not aware of a test standard that specified a particular voltage
>> >> for the PV cell.
>>
>> >> What standard is that?
>>
>> >> The standards I've seen with regard to PV panels are STC and PTC.
>>
>> >> But they both refer to wattage ratings under specified conditions of
>> >> irradiance, temperature and, for the PTC standard, wind speed. Neither one
>> >> mentions a particular voltage.
>>
>> >> NOCT is not mentioned in either of those standards, and the irradiance used
>> >> to determine NOCT is not the same as that used in either STC or PTC
>> >> standards.
>> >> --ron
>>
>> >Sad.
>>
>> It is truly sad that reality does not match George's fantasy.
>> --ron
>
>We're still waiting on your all inclusive spread sheet that allows for
>all the solar equipment in the world and complete pricing for same.
I'm sure *YOU* would require something like that, so you can blame any of
your misguided recommendations on whoever devised the database. But a real
solar power consultant would not.
>
>We are also waiting for yor caluclation for the numbers you proposed
>for this post;
And I'm waiting to see if you agree with any of them. Clearly, you cannot
recommend an efficient real-world system.
I was trying to help you formulate a real world system to run through the
simulation. Clearly, that is beyond your ability. Sad. Especially for
one who claims to be knowledgeable in this field.
In another post, GG writes about me: "He has learned more about solar
in the last two weeks than he ever learned in the last 10 years."
What I've learned in the last two weeks is that GG is even less competent,
and less able to learn, than I had originally concluded. That shouldn't be
a surprise, I know. But I did have hopes.
He can't specify either a real world panel or a real world battery for his
Kilauea water pump system. He can only come up with unrealistic
specifications, and, when real world specifications are proposed to him, he
can neither accept them, nor propose different ones.
And then, to compound his errors, he writes:
>This is your best guess is it? From the standard test temp of 25C my
>checking shows that at 45C:
>1) there is an increase of around 1%in the short circuit current
>
>2) A decrease of around 8.5% in the open circuit voltage
>
>3) A decrease of around 6% in the maximum power.
>>
If his 45C is an ambient temperature, he's someplace far from Kilauea, HI
where the highest annual temp is around 33C, and the average annual temp is
about 29C.
If he's trying to compare what happens at STC (which is at 25C), when we
change the conditions so that the operating cell temperature (OCT) is the
NOCT, then he doesn't know what NOCT is or how to calculate it.
Hint for GG: The OCT at STC will be higher than the NOCT.
--ron
Solar Flare
"brainchilds" here. Where does that put you?
Maybe a little maturity would help you out?
"Ron Rosenfeld" <ronros...@nospam.org> wrote in message
news:r5up74lddfq125shu...@4ax.com...
bea...@gmail.com
3) NOCT Normal Operating Cell Temperature. This is "C8" and is user
bea...@gmail.com
User input required at C8
>
> He's now bringing in PTC. I'm waiting for him to start talking about the
> GTC (Ghinius Test Conditions -- a proprietary and secret method of rating
> panels, which no manufacturer uses, but should, if they expect GG to
> recommend their products).
>
> --ron
You brought up PTC in hopes of muddying the water a bit more in your
quest to sound knowledgeable.
bea...@gmail.com
You are the one that suggested that such a SS would be a good thing.
>
>
>
> >We are also waiting for yor caluclation for the numbers you proposed
> >for this post;
>
> And I'm waiting to see if you agree with any of them. Clearly, you cannot
> recommend an efficient real-world system.
The numbers you provided add up to 11 panels.
Can't do it can you
>
> In another post, GG writes about me: "He has learned more about solar
> in the last two weeks than he ever learned in the last 10 years."
>
> What I've learned in the last two weeks is that GG is even less competent,
> and less able to learn, than I had originally concluded. That shouldn't be
> a surprise, I know. But I did have hopes.
Wow!
>
> He can't specify either a real world panel or a real world battery for his
> Kilauea water pump system. He can only come up with unrealistic
> specifications, and, when real world specifications are proposed to him, he
> can neither accept them, nor propose different ones.
180 Ah is true and correct minimum capacity for the job.
>
> And then, to compound his errors, he writes:
>
> >This is your best guess is it? From the standard test temp of 25C my
> >checking shows that at 45C:
> >1) there is an increase of around 1%in the short circuit current
>
> >2) A decrease of around 8.5% in the open circuit voltage
>
> >3) A decrease of around 6% in the maximum power.
>
> If his 45C is an ambient temperature, he's someplace far from Kilauea, HI
> where the highest annual temp is around 33C, and the average annual temp is
> about 29C.
The 45.2C was your number. The results I have shown are correct.
>
> If he's trying to compare what happens at STC (which is at 25C), when we
> change the conditions so that the operating cell temperature (OCT) is the
> NOCT, then he doesn't know what NOCT is or how to calculate it.
From the standard test temp of 25C my
> >checking shows that at 45C:
> >1) there is an increase of around 1%in the short circuit current
>
> >2) A decrease of around 8.5% in the open circuit voltage
>
> >3) A decrease of around 6% in the maximum power.
STC is the standard. The numbers given are what you get when you raist
the OCT to 45C.
Care to prove it wrong. But no, you can't. Sill of me to ask.
bea...@gmail.com
On Jul 16, 7:20 am, "Solar Flare" <solarfl...@hotmale.invalid> wrote:
> He seems smart enough to invoke many responses from the so-called
> "brainchilds" here. Where does that put you?
>
> Maybe a little maturity would help you out?
>
> "Ron Rosenfeld" <ronrosenf...@nospam.org> wrote in message
Ron Rosenfeld
If you are just comparing the output of the panel with a cell temperature
of 25C vs a cell temperature of 45C, then you are correct in your
assumption that the output will be less.
But you still remain unable to provide any real world materials for your
system.
And we're still waiting to hear where you got your 14Volt specification
from.
Since you falsely claim that 11 panels was my recommendation, let's be
clear that I was rounding up YOUR conclusion that 10.3 panels would be
enough. So I'll withdraw my 11 panel interpretation of your 10.3 panel
conclusion and wait for you to provide a panel that can be purchased at the
10.3 panel size.
Obviously you don't recall that my only recommendation was for 10 panels of
the type the OP had available, whereas *your* recommendations have been:
GG: (1st try) 154 panels
GG: (2nd try) 17- 50W Panels
GG: (3rd try) (C5 / C12) = 10.3
You can also tell us who makes a battery that meets *your* specifications
of:
B2 Maximum allowable depth of discharge = 70%
B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 180
C4 Battery efficiency = 90%
and will also work in the proposed application. So far you haven't even
come close.
--ron
Ron Rosenfeld
<solar...@hotmale.invalid> wrote:
>He seems smart enough to invoke many responses from the so-called
>"brainchilds" here. Where does that put you?
>
>Maybe a little maturity would help you out?
Yeah, I know. Trying to have a discussion with George is like mud
wrestling with a pig.
--ron
Ron Rosenfeld
>3) NOCT Normal Operating Cell Temperature. This is "C8" and is user
>input from the manufacturer's data.
Unfortunately, many do not supply it. So what will George do in that case?
--ron
bea...@gmail.com
> On Tue, 15 Jul 2008 16:04:49 -0700 (PDT), beal...@gmail.com wrote:
> >3) NOCT Normal Operating Cell Temperature. This is "C8" and is user
> >input from the manufacturer's data.
>
> Unfortunately, many do not supply it. So what will George do in that case?
> --ron
Request the information from the manufacturer.
bea...@gmail.com
No, I said 11 panels. 10.3 rounded up
>
> Obviously you don't recall that my only recommendation was for 10 panels of
> the type the OP had available, whereas *your* recommendations have been:
Thats right and I said 10.3 Rounded up to 11
>
> GG: (1st try) 154 panels
>
> GG: (2nd try) 17- 50W Panels
>
> GG: (3rd try) (C5 / C12) = 10.3
>
> You can also tell us who makes a battery that meets *your* specifications
> of:
>
> B2 Maximum allowable depth of discharge = 70%
Almost all deep cycle batteries. Most will in fact handle as much as
80% maximum DOD. Maximum DOD is a fairly rare occurrence in a properly
designed system.
> B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 180
180 is the minimum battery capacity required. I never recommended a
battery. You recommended T105s.
> C4 Battery efficiency = 90%
Hey, it works.
>
> and will also work in the proposed application. So far you haven't even
> come close.
I never recommended a battery for the application. You recommended
T205s.
> --ron
Ron Rosenfeld
>No, I said 11 panels. 10.3 rounded up
OK, I can use an 11 panel system in the simulation.
Now then, what size panel are you recommending?
You wrote previously:
>C8 Selected module I at 14 volts at NOCT 2.94A
>14 volts is the test standard at 25C. 17 volts is what the panel produces
>when not connected to a load.
Since the STC standard doesn't have a voltage specification of 14 Volts,
you still haven't explained what test standard you are referring to.
I suppose since you are specifying a panel that has an open circuit voltage
of 17 volts, it probably would put out only 14 volts under load.
>> You can also tell us who makes a battery that meets *your* specifications
>> of:
>>
>> B2 Maximum allowable depth of discharge = 70%
>
>Almost all deep cycle batteries. Most will in fact handle as much as
>80% maximum DOD. Maximum DOD is a fairly rare occurrence in a properly
>designed system.
>
>> B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 180
>
>180 is the minimum battery capacity required. I never recommended a
>battery. You recommended T105s.
>
>> C4 Battery efficiency = 90%
>
>Hey, it works.
>>
>> and will also work in the proposed application. So far you haven't even
>> come close.
>
>I never recommended a battery for the application. You recommended
>T205s.
Not in your system. I wondered if you would use that. I guess not.
I'd be happy to use any battery you want that meets your specifications in
the simulation. Same with the panel.
The only thing I've recommended were 10 panels of the type the OP said he
wanted to use; and also that he would need some sort of energy storage.
You've made multiple recommendations for imaginary equipment, and refused
to provide any examples of real world items that would even come close to
matching your specifications.
I've made a few suggestions as to equipment that might work, but you've
rejected them so far; and I've also asked for clarification of your
specifications, so as to make them useable, and you've been unable to even
do that.
------------------------------
So, George -- any real world panels & batteries that come close to matching
your specifications, and will work with your system design to allow the
OP's 2500W pump to work for 1/2 hr daily?
Here are George's partial specs for panels:
C8 Selected module I at 14 volts at NOCT 2.94A
17 volts is what the panel produces when not connected to a load.
I said 11 panels. 10.3 rounded up
Here are George's partial specs for a battery bank:
B2 Maximum allowable depth of discharge = 70%
B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 180
C4 Battery efficiency = 90%
--------------------------------------
Here are George's examples of equipment that might meet those
specifications:
<INTENTIONALLY LEFT BLANK>
------------------------------
--ron
Ron Rosenfeld
What manufacturer? What panel? What panel are you going to use in your
system that meets your specifications of:
>C8 Selected module I at 14 volts at NOCT 2.94A
and
>17 volts is what the produces when not connected to a load.
--ron
bea...@gmail.com
> On Wed, 16 Jul 2008 00:58:19 -0700 (PDT), beal...@gmail.com wrote:
> >No, I said 11 panels. 10.3 rounded up
>
> OK, I can use an 11 panel system in the simulation.
>
> Now then, what size panel are you recommending?
I have not recommended any particular panel, The op gave the
information. Try BP, they make a range of panels indifferent
wattages.
>
> You wrote previously:
>
> >C8 Selected module I at 14 volts at NOCT 2.94A
> >14 volts is the test standard at 25C. 17 volts is what the panel produces
> >when not connected to a load.
>
> Since the STC standard doesn't have a voltage specification of 14 Volts,
> you still haven't explained what test standard you are referring to.
>
> I suppose since you are specifying a panel that has an open circuit voltage
> of 17 volts, it probably would put out only 14 volts under load.
Mind like a steel trap*
>
>
>
> >> You can also tell us who makes a battery that meets *your* specifications
> >> of:
>
> >> B2 Maximum allowable depth of discharge = 70%
>
> >Almost all deep cycle batteries. Most will in fact handle as much as
> >80% maximum DOD. Maximum DOD is a fairly rare occurrence in a properly
> >designed system.
>
> >> B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 180
>
> >180 is the minimum battery capacity required. I never recommended a
> >battery. You recommended T105s.
>
> >> C4 Battery efficiency = 90%
>
> >Hey, it works.
>
> >> and will also work in the proposed application. So far you haven't even
> >> come close.
>
> >I never recommended a battery for the application. You recommended
> >T205s.
>
> Not in your system. I wondered if you would use that. I guess not.
I, personally, would never use T105s except in a golf cart.
>
> I'd be happy to use any battery you want that meets your specifications in
> the simulation. Same with the panel.
There is a whole world of batteries and panels to choose from.
>
> The only thing I've recommended were 10 panels of the type the OP said he
> wanted to use; and also that he would need some sort of energy storage.
>
> You've made multiple recommendations for imaginary equipment, and refused
> to provide any examples of real world items that would even come close to
> matching your specifications.
I have not made any recommendation as to equipment, imaginary or
otherwise.
>
> I've made a few suggestions as to equipment that might work, but you've
> rejected them so far; and I've also asked for clarification of your
> specifications, so as to make them useable, and you've been unable to even
> do that.
You suggested T105s. I have not rejected anything. I'm waiting for you
to propose your system.
>
> ------------------------------
> So, George -- any real world panels & batteries that come close to matching
> your specifications, and will work with your system design to allow the
> OP's 2500W pump to work for 1/2 hr daily?
Try;
They make some quite nice batteries
>
> Here are George's partial specs for panels:
>
> C8 Selected module I at 14 volts at NOCT 2.94A
> 17 volts is what the panel produces when not connected to a load.
> I said 11 panels. 10.3 rounded up
Based on OPs question. I did not recommend any particular panel.
>
> Here are George's partial specs for a battery bank:
>
> B2 Maximum allowable depth of discharge = 70%
> B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 180
> C4 Battery efficiency = 90%
> --------------------------------------
>
> Here are George's examples of equipment that might meet those
> specifications:
>
> <INTENTIONALLY LEFT BLANK>
Now if this is correct then all the other statements you have made
about equipment you have said I have recommended are lies.
>
> ------------------------------
>
> --ron
bea...@gmail.com
> On Wed, 16 Jul 2008 00:49:00 -0700 (PDT), beal...@gmail.com wrote:
> >On Jul 16, 11:53 am, Ron Rosenfeld <ronrosenf...@nospam.org> wrote:
> >> On Tue, 15 Jul 2008 16:04:49 -0700 (PDT), beal...@gmail.com wrote:
> >> >3) NOCT Normal Operating Cell Temperature. This is "C8" and is user
> >> >input from the manufacturer's data.
>
> >> Unfortunately, many do not supply it. So what will George do in that case?
> >> --ron
>
> >Request the information from the manufacturer.
>
> What manufacturer? What panel? What panel are you going to use in your
> system that meets your specifications of:
I have used BP, Solarex and Sharp in the past.
>
> >C8 Selected module I at 14 volts at NOCT 2.94A
>
> and
>
> >17 volts is what the produces when not connected to a load.
>
> --ron
The question is, what equipment are you going to use?
wmbjk...@citlink.net
>On Jul 16, 10:07 pm, Ron Rosenfeld <ronrosenf...@nospam.org> wrote:
>> On Wed, 16 Jul 2008 00:49:00 -0700 (PDT), beal...@gmail.com wrote:
>> >On Jul 16, 11:53 am, Ron Rosenfeld <ronrosenf...@nospam.org> wrote:
>> >> On Tue, 15 Jul 2008 16:04:49 -0700 (PDT), beal...@gmail.com wrote:
>> >> >3) NOCT Normal Operating Cell Temperature. This is "C8" and is user
>> >> >input from the manufacturer's data.
>>
>> >> Unfortunately, many do not supply it. So what will George do in that case?
>> >> --ron
>>
>> >Request the information from the manufacturer.
>>
>> What manufacturer? What panel? What panel are you going to use in your
>> system that meets your specifications of:
>
>I have used BP, Solarex and Sharp in the past.
Then it should be easy for you to quickly recommend a specific model
that meets the criteria *you've* specified. What's the holdup? As if
nobody can figure it out...
>>
>> >C8 Selected module I at 14 volts at NOCT 2.94A
>>
>> and
>>
>> >17 volts is what the produces when not connected to a load.
How the heck do you come up with this stuff? One has to wonder if
you've ever measured OC voltage, or even read a module label.
>The question is, what equipment are you going to use?
No, a better question is, why do you bother to pretend that you're a
"power consultant", considering that you're so frequently busted for
being hideously wrong? According to Google you've penned nearly 100
posts so far in this thread since your hilarious 154 panel
recommendation. Presumably your strategy is to convince readers that
you're not as dopey as you appear. Yet as usual, the only thing you've
accomplished is to advertise the shallowness of your knowledge.
Exactly how is more bungling supposed to make up for the initial
mistake? By now even the dimmest of the dim would have learned that
the goofiest quotes *will* be added to
http://www.citlink.net/~wmbjk/tbfduwisdumb.htm. So why do you keep
writing them?
Wayne
wmbjk...@citlink.net
<ronros...@nospam.org> wrote:
<snipped usual ghinius blizzard of obfuscation>
>
>This post clearly demonstrates that George doesn't know what NOCT is, even
>though he uses it in his useless spreadsheet. He also doesn't know how to
>measure or estimate it, nor does he realize the consequences of making
>measurements at a test temperature of 25°C vs measurements at a NOCT of
>45°C.
>--ron
Just add it to the list of what he pretends to know.
http://www.citlink.net/~wmbjk/tbfduwisdumb.htm It might be easier to
list what he *does* know. Anybody? Bueller?
Wayne
bea...@gmail.com
> On Tue, 15 Jul 2008 09:56:19 -0400, Ron Rosenfeld
>
>
> <snipped usual ghinius blizzard of obfuscation>
>
>
>
> >This post clearly demonstrates that George doesn't know what NOCT is, even
> >though he uses it in his useless spreadsheet. He also doesn't know how to
> >measure or estimate it, nor does he realize the consequences of making
> >measurements at a test temperature of 25°C vs measurements at a NOCT of
> >45°C.
> >--ron
>
> list what he *does* know. Anybody? Bueller?
>
> Wayne
Tell us about your system Tweedledum. What are the loads? How many
Watts do they draw? How long are they run. And don't forget the big
one, How does increasing the load reduce line losses(Voltage Drop)
Ron Rosenfeld
No, the question is what panel meets YOUR specifications and will work in
the system you designed for.
Those companies make lots of panels, but I don't see any that meet YOUR
specifications.
GG's specifications for panels:
> C8 Selected module I at 14 volts at NOCT 2.94A
Ron Rosenfeld
I, I see. Now your blathering about numbers of panels with certain
characteristics, and a battery bank with certain specifications, were not
recommendations for imaginary equipment either. Clearly they were not
recommendations for real equipment, since nothing exists with those
specifications.
Obviously you cannot read.
I've claimed that you have been UNABLE to recommend any specific equipment
and asked you repeatedly for specific recommendations. I've made a few
suggestions of stuff that might meet YOUR specifications, but so far as I
can tell, you've never recommended anything usable. Even your so-called
specifications are useless.
--ron
Ron Rosenfeld
>Just add it to the list of what he pretends to know.
>http://www.citlink.net/~wmbjk/tbfduwisdumb.htm It might be easier to
>list what he *does* know. Anybody? Bueller?
List of what George pretends to know:
http://www.citlink.net/~wmbjk/tbfdulist.htm
--ron
bea...@gmail.com
> On Wed, 16 Jul 2008 07:01:35 -0700, wmbjkREM...@citlink.net wrote:
> >Just add it to the list of what he pretends to know.
> >http://www.citlink.net/~wmbjk/tbfduwisdumb.htm It might be easier to
> >list what he *does* know. Anybody? Bueller?
>
> List of what George pretends to know:
>
> http://www.citlink.net/~wmbjk/tbfdulist.htm
>
> --ron
Ron, In my first reply I made it quite clear that there was not enough
information and suggested;
"Perhaps you would like to re-phrase the question. Do you envision the
use of batteries and inverter?"
In my second post I said;
"Best ditch the pump."
The whole idea of running a 2500W pump for half an hour off a PV
installation is ludicrous.
For a fraction of the money the OP could set up a farm windmill pump
and tank or even a solar pump and tank. Gravity still works.
But the problem is that the OP probably has a pumping set up in place
and wants to take it off grid.
You keep saying that I have suggested equipment. This is untrue. So
far in this discussion the only equipment suggested was by you. This
equipment being T105 batteries.
As far as the formula is concerned the only recommendation was the
minimum battery capacity.
Now, you have the formula, it requires user input. Can you do it? I
don't think you can. You talk the talk, but, you can't walk the walk.
I have already calculated the system. The thing is though, if I post
it now, you will whine and cry and carry on like a two bob watch. So,
you want to see my hand, put your cards on the table.
bea...@gmail.com
This is user input. I have not put anything in there yet.
> > 17 volts is what the produces when not connected to a load.
This is true. It is also not part of the formula.
>
> --ron
bea...@gmail.com
I have not suggested any equipment at all. The only equipment
suggested was suggested by you, namely T105 batteries
I have not recommended any specific equipment. I provided the correct
formula, the formula requires user input.
> I've made a few
> suggestions of stuff that might meet YOUR specifications,
No. you made one recommendation. This was for T105 batteries
> but so far as I
> can tell, you've never recommended anything usable.
I have not recommended any specific equipment at all. Usable or
otherwise.
> Even your so-called specifications are useless.
The only specification is the minimum battery capacity, it is
correct.
> --ron
wmbjk...@citlink.net
>On Jul 17, 3:15 am, Ron Rosenfeld <ronrosenf...@nospam.org> wrote:
>> On Wed, 16 Jul 2008 07:01:35 -0700, wmbjkREM...@citlink.net wrote:
>> >Just add it to the list of what he pretends to know.
>> >http://www.citlink.net/~wmbjk/tbfduwisdumb.htm It might be easier to
>> >list what he *does* know. Anybody? Bueller?
>>
>> List of what George pretends to know:
>>
>> http://www.citlink.net/~wmbjk/tbfdulist.htm
>>
>> --ron
>
>Ron, In my first reply I made it quite clear that there was not enough
>information and suggested;
>
>"Perhaps you would like to re-phrase the question. Do you envision the
>use of batteries and inverter?"
Yes, but *first* you supplied your mind-numbing calculations to
demonstrate that he needed 154 panels!
>In my second post I said;
>
>"Best ditch the pump."
Yes, but only *after* you'd been corrected, and had read others'
recommendations to consider alternatives.
>The whole idea of running a 2500W pump for half an hour off a PV
>installation is ludicrous.
Baloney. Powering pumps with PV is done routinely, which you'd know if
you got out more. Lots of folks have the experience you lack, and have
written about it. Why not learn by reading that rather than making
idiotic declarations?
>For a fraction of the money the OP could set up a farm windmill pump
>and tank or even a solar pump and tank. Gravity still works.
You don't know what you're talking about. Pressurizing water to normal
levels takes energy, and unless one has some scrounging ability or
whatever, they'll generally have to spend some serious money. The job
can't be accomplished by "gravity", or by one of your previous
nitwitted suggestions, solar suction. If you think it can be done "for
a fraction of the cost", then let's see you explain how, including
curves. Here, I'll supply the parameters - 8gpm, 80ft of head. Now,
*exactly* what do you recommend, and how much will it cost?
>But the problem is that the OP probably has a pumping set up in place
>and wants to take it off grid.
The only "problem" here is that a nitwit has managed to turn a simple
question into a glaring advertisement for his lack of experience.
>You keep saying that I have suggested equipment. This is untrue.
Nonsense.
George Ghio, June 19/2008 "14 panels in series to give you 238V @ 3A
11 parallel strings to give you 2530A = 154 panels"
George Ghio, June 19/2008 "300Ah Battery 17- 50W Panels"
etc, etc.
>I have already calculated the system.
... several times!
> The thing is though, if I post
>it now, you will whine and cry and carry on like a two bob watch.
For a hundred posts you've been claiming that calculating this stuff
is "simple", and as usual you insist on proving it <snorf> by posting
multiple and variously wrong answers to a single question. But now
you're saying that you have yet *another* result that is finally
correct, except it's a secret. Too funny.
>So,
>you want to see my hand, put your cards on the table.
Reminds me of the time you backed yourself into a corner and demanded
non-disclosure agreements before you'd explain the secret solution.
You'll never learn.
Wayne
Ron Rosenfeld
>> GG's specifications for panels:> C8 Selected module I at 14 volts at NOCT 2.94A
>
>This is user input. I have not put anything in there yet.
Then who put in the 14 volts at NOCT 2.94A, if not you???
>
>> > 17 volts is what the produces when not connected to a load.
>
>This is true. It is also not part of the formula.
>>
You claim this is true, but I've not seen a 50 watt panel designed for a
12V system with a 17V output when "not connected to a load" (i.e.
open-circuit). If it exists, let us know.
--ron
Ron Rosenfeld
>On Jul 17, 3:15 am, Ron Rosenfeld <ronrosenf...@nospam.org> wrote:
>> On Wed, 16 Jul 2008 07:01:35 -0700, wmbjkREM...@citlink.net wrote:
>> >Just add it to the list of what he pretends to know.
>> >http://www.citlink.net/~wmbjk/tbfduwisdumb.htm It might be easier to
>> >list what he *does* know. Anybody? Bueller?
>>
>> List of what George pretends to know:
>>
>> http://www.citlink.net/~wmbjk/tbfdulist.htm
>>
>> --ron
>
>Ron, In my first reply I made it quite clear that there was not enough
>information and suggested;
>
>"Perhaps you would like to re-phrase the question. Do you envision the
>use of batteries and inverter?"
>
>In my second post I said;
>
>"Best ditch the pump."
>
>The whole idea of running a 2500W pump for half an hour off a PV
>installation is ludicrous.
>
>For a fraction of the money the OP could set up a farm windmill pump
>and tank or even a solar pump and tank. Gravity still works.
>
>But the problem is that the OP probably has a pumping set up in place
>and wants to take it off grid.
>
>You keep saying that I have suggested equipment. This is untrue. So
>far in this discussion the only equipment suggested was by you. This
>equipment being T105 batteries.
You made multiple recommnedations as to numbers of PV Panels. Your last
one was for 11 panels with a particular specification:
>C8 Selected module I at 14 volts at NOCT 2.94A
>
>As far as the formula is concerned the only recommendation was the
>minimum battery capacity.
Not so -- you recommended a minimum battery capacity at the 100 hr rate,
and also with a certain efficiency and maximum DOD levels.
>
>Now, you have the formula, it requires user input. Can you do it? I
>don't think you can. You talk the talk, but, you can't walk the walk.
>I have already calculated the system. The thing is though, if I post
>it now, you will whine and cry and carry on like a two bob watch. So,
>you want to see my hand, put your cards on the table.
I'll grant that you did not specify any makes or models of equipment, but
you did post specifications which you claimed would work.
If you have a real system that will work, and that also comes close to
meeting your previously posted specifications, I'd be very surprised.
GG specifications for battery bank:
B2 Maximum allowable depth of discharge = 70%
B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 180
C4 Battery efficiency = 90%
GG specifications for panels:
C8 Selected module I at 14 volts at NOCT 2.94A
C9 Selected module nominal operating voltage. = 12V
C10 Guaranteed current (C8 x 0.9) = 2.65A
C11 Number of modules in series (A7 / C9) = 1
C12 Output per module (C10 x C6) = 13.2Ah
C13 Number of parallel strings of modules (C5 / C12) = 10.3
Specifically, I believe the battery you specify will have a MUCH larger
capacity at the 100 hr rate than the 180Ah you specified.
And I believe, if you stick with 50 watt panels, that the I at 14 volts at
NOCT will be very different from 2.94A.
--ron
Ron Rosenfeld
>The whole idea of running a 2500W pump for half an hour off a PV
>installation is ludicrous.
>
>For a fraction of the money the OP could set up a farm windmill pump
>and tank or even a solar pump and tank. Gravity still works.
>
>But the problem is that the OP probably has a pumping set up in place
>and wants to take it off grid.
All the OP has provided is the pump specifications and how often he wants
to use it. We don't know how much he is paying for electricity (although
PVWATTS says the state average is $0.18USD per kWh). If he needs to extend
the grid in order to use the pump, it might well be cost effective.
And as I wrote in my (only) response to the OP:
"But it should be clear that if you want to run your pump every day, you
will need some kind of storage ...
"You can store electricity, or you can store water. Five days supply is
the usual recommendation. If you store water, you'll need to have room for
a large enough tank. But if you do that, you can use a different pump that
runs off DC, and not require batteries or an inverter.
A solar powered DC pump and water storage would make a lot more sense to me
than a windmill.
--ron
wmbjk...@citlink.net
<ronros...@nospam.org> wrote:
>On Wed, 16 Jul 2008 17:04:16 -0700 (PDT), bea...@gmail.com wrote:
>
>>The whole idea of running a 2500W pump for half an hour off a PV
>>installation is ludicrous.
>>
>>For a fraction of the money the OP could set up a farm windmill pump
>>and tank or even a solar pump and tank. Gravity still works.
>A solar powered DC pump and water storage would make a lot more sense to me
>than a windmill.
>--ron
Second that. For submersible apps, a typical good-quality solar
installation is about $3k (plus pipe etc.), or ballpark, pretty
similar to a conventional pump with batteries, inverter etc. For
small-demand applications the conventional setup is sometimes cheaper,
especially if it's part of a larger system. Once the demand increases,
the solar solution is more economical. But the wind alternative, at
least the old-fashioned high-torque Aeromotor setup, can easily be 3
times the price, *and* far more labor intensive to install and
maintain. http://www.deanbennett.com/windmill-catalog-page53.pdf The
tower alone can cost more than the entire solar setup. Where the
ghinius ever got the idea that such things can cost "a fraction of the
money", is probably the same place where "gravity" can do the job. :-)
As hard as it is to imagine, I think he may be getting stupider with
each passing day.
Wayne
Morris Dovey
> Second that. For submersible apps, a typical good-quality solar
> installation is about $3k (plus pipe etc.), or ballpark, pretty
> similar to a conventional pump with batteries, inverter etc. For
> small-demand applications the conventional setup is sometimes cheaper,
> especially if it's part of a larger system. Once the demand increases,
> the solar solution is more economical. But the wind alternative, at
> least the old-fashioned high-torque Aeromotor setup, can easily be 3
> times the price, *and* far more labor intensive to install and
> maintain. http://www.deanbennett.com/windmill-catalog-page53.pdf The
> tower alone can cost more than the entire solar setup. Where the
> ghinius ever got the idea that such things can cost "a fraction of the
> money", is probably the same place where "gravity" can do the job. :-)
> As hard as it is to imagine, I think he may be getting stupider with
> each passing day.
Long thread with lots of expert opinion - but I didn't seem to have
received the post where the OP told how much water need to be lifted how
high...
Would someone who did see that info please post it?
--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/
bea...@gmail.com
Morris Dovey
> Bingo.
I'd really like to advocate a direct solar-powered (no electricity
involved) pumping solution of the sort described on a number of web
pages at the link below, but find it really difficult to offer a
solution when I haven't seen a statement of the problem.
There's a photo of a prototype engine at the bottom of the page at the
"Fluidyne Engine Description" link, and a schematic of a pump using such
an engine at another link.
The concept shown at the "Pumped Hydro Energy Storage" page could
perhaps be employed to fill a pond or tank just above the area needing
the water.
Note that the only moving parts in the engine are air and water (which
probably won't wear out in the OP's lifetime) and that the engine was
constructed largely of 4-inch PVC drain pipe - a fairly low-cost and
commonly available material.
--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA