low cost solar panel tracker
Thomas Magma
Here is a new product that could help a lot of you guys that have solar
panels and rely on the solar power. It is a controller that connects
directly to the actuator arm of the old satellite dishes. Just replace the
dish with your panels. It will move your panels into the sun during the day
and rewind them during the night. Some studies have shown this to increase
your panels output up to 40% The old satellite dish assemblies are easy to
find if you look around.
Here is the link www.solarsundial.com The are some pictures of typical
installations on the site.
George Ghio
"Thomas Magma" <some...@overtherainbow.com> wrote:
Some studies are full of shit.
30% on a good day, maybe.
Perhaps 10% for a good year.
wmbjk
To borrow a phrase... would you have any evidence for this article of
faith?
Wayne
George Ghio
wmbjk <wmbjk@REMOVE_THIScitlink.net> wrote:
Wayne, you are an incompetent boobie. Given that you can't document your
own system it is clear that any advice you give is suspct.
wmbjk
<gh...@netconnect.com.au> wrote:
>In article <0t6gl0herof81gakc...@4ax.com>,
> wmbjk <wmbjk@REMOVE_THIScitlink.net> wrote:
>> >Some studies are full of shit.
>> >
>> >30% on a good day, maybe.
>> >
>> >Perhaps 10% for a good year.
>> To borrow a phrase... would you have any evidence for this article of
>> faith?
>Wayne, you are an incompetent boobie. Given that you can't document your
>own system it is clear that any advice you give is suspct.
What would you call someone who holds an opinion without a shred of
proof to back it up? Perhaps a one-man cargo cult...
Here are some links to information demonstrating that your tracker
efficiency claims are nonsense.
http://www.homepower.com/files/hp25-56.pdf
http://rredc.nrel.gov/solar/old_data/nsrdb/atlas/redbook/
You might send those two organizations your comments disputing their
data. Or you could beat yourself over the head with an, ah... unique
opinion for a while longer.
Wayne
Duane C. Johnson
George Ghio <gh...@netconnect.com.au> wrote:
> "Thomas Magma" <some...@overtherainbow.com> wrote:
>> Here is a new product that could help a lot of you guys
>> that have solar panels and rely on the solar power. It
>> is a controller that connects directly to the actuator
>> arm of the old satellite dishes. Just replace the dish
>> with your panels. It will move your panels into the sun
>> during the day and rewind them during the night. Some
>> studies have shown this to increase your panels output
>> up to 40% The old satellite dish assemblies are easy to
>> find if you look around. Here is the link
>> www.solarsundial.com The are some pictures of typical
>> installations on the site.
> Some studies are full of shit.
Which studies would they be?
> 30% on a good day, maybe.
This year I was at the MREA energy fair one of the days
was perfectly cloudless all day from sunup to sundown.
This was at the summer solstice.
The latitude was close to 45 degrees.
Sunup and sundown occurred at angles of about +- 135 degrees
from south or a total af about 270 degrees.
I estimate that full PV panel output doesn't occur until
the sun is over 10 degrees above the horizon so I
will subtract about 30 degrees from the 270 for a full
output for 240 degrees.
240deg / 360deg * 24 hours/day = 16 full output hours per day
Now lets say the panel was un-tracked optimally oriented
fixed mount. I made a spreadsheet that calculates the
output based on cosine loss and reflection loss after
60 degrees. This spreadsheet shows that there is the
equivalent of about 6.6 full output hours.
Ok, this is actually spread over 12 hours.
(If you want the spreadsheet I can send it to you.)
So, this day I calculate:
16hr/6.6hr = 242%
This is an improvement of 142% for an optimally track
PV panel over an optimally mounted fixed PV panel.
That's a lot more than just a 30% improvement on you
good day.
> Perhaps 10% for a good year.
I'm not going to do this for a whole year as it's
an extensive calculation.
Most people are interested in real outputs including
weather.
The NREL site has real measured data. Then they smooth
the data between measurement sites to produce very
useful data. Depending on the location most locations
far exceed your pessimistic numbers.
Duane
--
Home of the $35 Solar Tracker Receiver
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George Ghio
wmbjk <wmbjk@REMOVE_THIScitlink.net> wrote:
own system it is clear that any advice you give is suspect.
George Ghio
Peak Sun Hours. Yes
> (If you want the spreadsheet I can send it to you.)
I would like to see the spreadsheet. Thank you
>
> So, this day I calculate:
> 16hr/6.6hr = 242%
> This is an improvement of 142% for an optimally track
> PV panel over an optimally mounted fixed PV panel.
>
> That's a lot more than just a 30% improvement on you
> good day.
Great. One day. I guess all the worlds energy problems are now solved
and we can all go home;-}
Now you and I both know that the data from one day, the longest day in
the year at that, is useless.
>
> > Perhaps 10% for a good year.
>
> I'm not going to do this for a whole year as it's
> an extensive calculation.
>
> Most people are interested in real outputs including
> weather.
So why do you parade such nonsense as the one day result. The result
from the longest day of the year under perfect conditions.
>
> The NREL site has real measured data. Then they smooth
> the data between measurement sites to produce very
> useful data. Depending on the location most locations
> far exceed your pessimistic numbers.
Granted. But I also take into account the times the tracker points the
panels at the wrong part of the sky, the times the tracker just fails to
work and operator errors. Not to mention site conditions.
Reality is a far cry from theory in most cases.
George
Duane C. Johnson
George Ghio <gh...@netconnect.com.au> wrote:
> In article <4158BCEF...@redrok.com>,
> "Duane C. Johnson" <red...@redrok.com> wrote:
>
>
>>Hi George;
>>
>>George Ghio <gh...@netconnect.com.au> wrote:
>>
>>
>>>"Thomas Magma" <some...@overtherainbow.com> wrote:
>>
>> >> Here is a new product that could help a lot of you guys
>> >> that have solar panels and rely on the solar power. It
>> >> is a controller that connects directly to the actuator
>> >> arm of the old satellite dishes. Just replace the dish
>> >> with your panels. It will move your panels into the sun
>> >> during the day and rewind them during the night. Some
>> >> studies have shown this to increase your panels output
>> >> up to 40% The old satellite dish assemblies are easy to
>> >> find if you look around. Here is the link
>> >> www.solarsundial.com The are some pictures of typical
>> >> installations on the site.
>>
>> > Some studies are full of shit.
>>
>>Which studies would they be?
Which studies?
The NREL data is pretty good.
>> > 30% on a good day, maybe.
>>
>>This year I was at the MREA energy fair one of the days
>>was perfectly cloudless all day from sunup to sundown.
>>This was at the summer solstice.
>>The latitude was close to 45 degrees.
>>Sunup and sundown occurred at angles of about +- 135 degrees
>>from south or a total af about 270 degrees.
>>I estimate that full PV panel output doesn't occur until
>>the sun is over 10 degrees above the horizon so I
>>will subtract about 30 degrees from the 270 for a full
>>output for 240 degrees.
>>240deg / 360deg * 24 hours/day = 16 full output hours per day
>>
>>Now lets say the panel was an un-tracked optimally oriented
>>fixed mount. I made a spreadsheet that calculates the
>>output based on cosine loss and reflection loss after
>>60 degrees. This spreadsheet shows that there is the
>>equivalent of about 6.6 full output hours.
>>Ok, this is actually spread over 12 hours.
I should note that I used 60 degree as the reflection
cutoff angle. With most panels this angle is closer to
45 degrees.
> Peak Sun Hours. Yes
Well yes. That's because you said the "good day"
was only 30% improvement over non tracked.
So I gave you the real "good day" improvement of
142% at summer solstice.
>>(If you want the spreadsheet I can send it to you.)
> I would like to see the spreadsheet. Thank you
I tried but your address didn't work.
So I'll attach it here.
> gh...@netconnect.com.au
>
>>So, this day I calculate:
>>16hr/6.6hr = 242%
>>This is an improvement of 142% for an optimally track
>>PV panel over an optimally mounted fixed PV panel.
>>
>>That's a lot more than just a 30% improvement on you
>>good day.
>
>
> Great. One day. I guess all the worlds energy problems
> are now solved and we can all go home;-}
Of course not. However, giving bogus unrealistically
pessimistic data doesn't help things.
BTW, have you used a good solar tracker and taken
measurements at your site?
> Now you and I both know that the data from one day,
> the longest day in the year at that, is useless.
Of course. That's why I did it.
But you did it also.
Readers might have gotten the impression that
if the "good day" had only a 30% improvement
that all real days would be less than 30%.
This is just not true.
It's a lot better than that.
We just have to use the NREL data to find out
what the real values are.
>>>Perhaps 10% for a good year.
>>
>>I'm not going to do this for a whole year as it's
>>an extensive calculation.
>>
>>Most people are interested in real outputs including
>>weather.
>
>
> So why do you parade such nonsense as the one day result. The result
> from the longest day of the year under perfect conditions.
Because that's what you were using, a "good day".
>>The NREL site has real measured data. Then they smooth
>>the data between measurement sites to produce very
>>useful data. Depending on the location most locations
>>far exceed your pessimistic numbers.
>
>
> Granted. But I also take into account the times the tracker points the
> panels at the wrong part of the sky, the times the tracker just fails to
> work and operator errors. Not to mention site conditions.
OK, what losses are you describing?
Can you give an example?
Sometimes the best direction to aim is not at the sun
when there are overcast conditions. A sensor type tracker
finds this optimum direction.
Some sites have good smog reflection. So the sensor type tracker
will bias the direction in these directions. That's not a loss,
that's a gain.
> Reality is a far cry from theory in most cases.
I agree. But my customers say the real world improvement
throughout the year averages much better than a 30% improvement.
I have discouraged customers from tracking that have odd
local conditions such as smog and fog conditions that
limit solar to the mid day.
Actually these conditions show up in the NREL data.
Hopefully you have this type of quality data in
Australia.
> George
George Ghio
No, I just get called out to fix the bloody things.
My site would not benefit from a tracker. I have a window of opportunity
for solar. Lots of trees and a hill that has the optimistic name of
Mount Moliagul.
>
> > Now you and I both know that the data from one day,
> > the longest day in the year at that, is useless.
>
> Of course. That's why I did it.
> But you did it also.
>
> Readers might have gotten the impression that
> if the "good day" had only a 30% improvement
> that all real days would be less than 30%.
> This is just not true.
> It's a lot better than that.
> We just have to use the NREL data to find out
> what the real values are.
I have as yet to find anyone that has done much better over the space of
the year.
>
> >>>Perhaps 10% for a good year.
> >>
> >>I'm not going to do this for a whole year as it's
> >>an extensive calculation.
> >>
> >>Most people are interested in real outputs including
> >>weather.
> >
> >
> > So why do you parade such nonsense as the one day result. The result
> > from the longest day of the year under perfect conditions.
>
> Because that's what you were using, a "good day".
Fair enough.
>
> >>The NREL site has real measured data. Then they smooth
> >>the data between measurement sites to produce very
> >>useful data. Depending on the location most locations
> >>far exceed your pessimistic numbers.
> >
> >
> > Granted. But I also take into account the times the tracker points the
> > panels at the wrong part of the sky, the times the tracker just fails to
> > work and operator errors. Not to mention site conditions.
>
> OK, what losses are you describing?
> Can you give an example?
Gave at least two. The third 'site conditions' See above. Operator
Error is just as it says. Mostly people who think they know better than
the designer.
>
> Sometimes the best direction to aim is not at the sun
> when there are overcast conditions. A sensor type tracker
> finds this optimum direction.
>
> Some sites have good smog reflection. So the sensor type tracker
> will bias the direction in these directions. That's not a loss,
> that's a gain.
What I said was the wrong direction.
>
> > Reality is a far cry from theory in most cases.
>
> I agree. But my customers say the real world improvement
> throughout the year averages much better than a 30% improvement.
>
> I have discouraged customers from tracking that have odd
> local conditions such as smog and fog conditions that
> limit solar to the mid day.
I have the same trouble with wind generators here.
>
> Actually these conditions show up in the NREL data.
>
> Hopefully you have this type of quality data in
> Australia.
Thank you for the SS. Will see what I can do for data.
george
George Ghio
"Duane C. Johnson" <red...@redrok.com> wrote:
Question: Hours and Angle =
Time of day and Angle of sun
Also is this at 45 deg
George
Duane C. Johnson
George Ghio wrote:
> "Duane C. Johnson" <red...@redrok.com> wrote:
> Question: Hours and Angle =
I broke the day into 72 20 minute segments.
The angle is the position of the sun in right ascension.
Then I take the cosine of this angle.
This represents the output of the panel with
1 being 100% output and 0 no output.
Then I exclude the cosines that are negative as the
sun is behind the fixed panel.
Then I exclude the times the suns angle is to low
because the light is lost to the panel due to reflection.
I believe this is called the Snell total reflection angle.
I choose 60 degrees to give the benefit of the doubt.
Most glass has a reflection angle closer to 45 degrees.
Of course some panels can get closer to 60 degrees because
they either have plastic or anti reflection coatings.
All surfaces have a total reflection at some angle.
Last, I take the average of the last column which
results in the equivalent peak output hours per day.
> Time of day and Angle of sun
The time in hours is solar or sidereal time
with hour 12 being due south.
> Also is this at 45 deg
This was for a location with a latitude of 45 degrees.
What is your latitude George?
You mentioned that you have a limited solar visibility
where you want your panels located. I might suggest
that you use one or two heliostats located in a location
where the sun visibility is better and send the light
back to the fixed panels. This low amount of concentration
is safe and can effectively multiply the panels output
power in addition to increasing the time output is available.
George Ghio
Second, just so you get an idea of where I am coming from,
I have done a set of these charts for the whole of Australia in 1/2
degree increments.
As you can see I know how the sun moves across the sky.
If I may I would like to incorporate your SS into the data to produce a
further chart to compliment these charts. This of course depends on
getting my software up and running after a computer upgrade.
In article <415AAD13...@redrok.com>,
36.44 south
>
> You mentioned that you have a limited solar visibility
> where you want your panels located. I might suggest
> that you use one or two heliostats located in a location
> where the sun visibility is better and send the light
> back to the fixed panels. This low amount of concentration
> is safe and can effectively multiply the panels output
> power in addition to increasing the time output is available.
I have enough to supply my needs. Which are quite small. Around 1.2kWh a
day. Also during winter I make use of reflection off the roof. The roof
being zink-alum corrie it gives a nice boost of diffuse light. Not much
point in getting to complicated about things.
>
> > George
>
> Duane