New PV System being considered
Phil
I'm a UK Newbie to this group. I live in the North West Uk, and I'm
considering getting a 1.5 kW PV system.
I'm getting the system to "do my bit for global warming" and to reduce
monthly outgoings on Power.
I've been quoted ~ £8K for a 1.5 KW PV system.
I'm intending to sell spare power back to Grid Supplier (not much I'm sure).
Has anyone got any recommendations ?
Cheers,
Phil.
Jussi Saily
What exactly was your question, where to get it cheaper or what?
Anyway, getting a large solar array might not exactly pay out if you
weigh the investment costs and grid power cost. You might consider
also a small wind power plant in addition to the solar panels. You
would get wind power when the sun doesn't shine, which is a large
portion of time in the UK (and here in Finland, too!).
-- Jussi
Eeyore
Phil wrote:
> Hi
>
> I'm a UK Newbie to this group. I live in the North West Uk, and I'm
> considering getting a 1.5 kW PV system.
Don't bother. The insolation there is rubbish.
http://re.jrc.ec.europa.eu/pvgis/countries/europe/g13y_uk_ie.png
That's about 900kWh / m2 annually. or averaged at ~ 2.5 kWh daily /m2
Multiply by the efficiency of a GOOD panel at 15% and ever sq metre of PV solar
panel will generate you a massive 375Wh daily. Furthermore of course, a lot less
in the winter.
Sp you'd need 4 sq metre panels just to get 1.5kWh for one hour ! To get an
average of 1.5kW throughout the day you would need 4 x 24 = ~ 100 sq metre
panels and a collosal bank of battrweries, inverters and so on. I'd estimate
cost in the hundreds of thousands plus the batteries will need replacing every
10 years at best as they 'wear out'.
Rememeber PV omnly generates when the sun's shing and you won't get much on
cloudy days either.
And don't bother with those home wind turbines either, they're another con.
> I'm getting the system to "do my bit for global warming" and to reduce
> monthly outgoings on Power.
Fit CFLs in your light fittings and put a foot of insulation in your roof ! Fill
cavity walls with blown rockwool or the like. Double glazing funnilly enough is
quite low on the list of useful things to do.
Reducing USE is the thing to do. Insulation is your friend in summer and winter.
> I've been quoted ~ £8K for a 1.5 KW PV system.
Some one has a BIG sense of humour. Let's see the details of this quote !
> I'm intending to sell spare power back to Grid Supplier (not much I'm sure).
You won't have any.
> Has anyone got any recommendations ?
See above. You might also want to see a phsychiatrist.
Graham
Eeyore
Jussi Saily wrote:
What he needs to do is understand the calculations. Then he'll run a mile.
Wind turbines are worthless in urban areas since buildings, trees and foliage act
as wind breaks. Plus the fact that the wind at rooftop height is a fraction of the
government figures which are measured at 25m height IIRC.
You may also do structural damage to your hiome.
Graham
Bruce Harvey
news:48B9D377...@hotmail.com...
Regardless of the reply above, if you need more info then you will need to
start with reducing your usage first. The best place to start is to draw up
a table or download one from the internet to calculate your usage and where
it is going. Then compare that to what the utility company is charging you
per kWh. Work out how much each appliance in your house is using especially
for water heating and space heating/air conditioning. These things will
reduce your usage considerably in most cases and will give a better return
on your investment. Then after that is done and the insulation on your house
is up to scratch you could have another look. Remember the best way to save
the environment is not to use it up in the first place. The other thing to
consider is are you able to sell back to your electricity supplier, how much
will metering cost, and with wind turbines you need to find out what your
average wind is year round. Also note that unlike PV solar, wind turbines
are not silent and there may be local or other government restrictions on
their installation especially in urban areas. This is just the start. BTW
going by Australian prices and exchange rates the 8,000 pound price tag does
not sound too ridiculous but it may not perform to its full ability in your
area. Another thing to consider is does it snow where you are as this can
INCREASE you winter power production in some cases but may increase
installation costs as the panels cant be cleaned with a shovel after a snow
fall. There is a whole other set of information to consider if that is the
case. Another thing to think about is does your roof face south or not. If
not, mounting the panels may be more expensive.
Just a rudimentary start but I hope this helps a bit.
My system is 2.8kW PV, solar hot water, 30deg S of the equator and $45,000
to get connected to the grid. It was worth it for me here in Australia but
mine was definitely a special case. Don't assume it will work for you. Do
the research and calculate the costs and returns on your options and that
will tell you the best way to go and where to start. Every situation is
different. I also suggest talking to anyone in your area who has a solar
panel on the roof and ask them about their experience. The people who try
these things are usually proud of their achievements and love to share
information. The worst they can say is, go away.
Bruce
Eeyore
Bruce Harvey wrote:
> "Eeyore" wrote in message
> >
> > You may also do structural damage to your hiome.
>
>
> Regardless of the reply above, if you need more info then you will need to
> start with reducing your usage first.
I think you'll find that's what I said too. And in Northern England INSULATION
is the big one.
You need a foot of classic loft / roof insulation and if the property was built
with cavity walls (most houses in the UK are built of building block and brick
with an air gap inbetween and tied together, blow an insulating material like
rockwool into it.
Graham
Eeyore
Bruce Harvey wrote:
> BTW
> going by Australian prices and exchange rates the 8,000 pound price tag does
> not sound too ridiculous
NOT for 1.5 kW 24/7 ! Then again the OP phrased his question hopelessly which
suggests he hasn't the tiniest clue how it all works.
One thing for sure, spending ANY money on PV in Northern England is doing bugger
all for the environment and making some people very wealthy.
Graham
Mauried
An interesting exercise for the OP would be to ask for an itemised
quote for the Solar System.
Ask questions like
How much for the panels.
How much for the Inverter.
How much to install it all.
If you actually get any figures for the above , then go and look up
the prices for the same items on the Net.
Ive done this several times just out of interests sake , and most
installers wont give you this info,and its pretty obvious why.
The install charges make up some 30% of the total cost.
Getting Solar panels installed is wimply making Installers very
wealthy.
Eeyore
Phil wrote:
> I've been quoted ~ £8K for a 1.5 KW PV system.
Chances are at best that it PEAKS at 1.5kW for a couple of hours a day.
Since you have missed out the most important data i.e. how many *kWh* you want
then you're going to be led by the nose up the garden path by unscrupulous
installers.
Graham
bea...@gmail.com
I'll tell you something as a designer and installer of systems, on a
typical system, the cost of the components alone at retail prices can
net the installer anything between $3,000 to $10,000 straight up
profit. Then they have the gall to ask for a couple more K for the
installation.
Too many cowboys in the industry selling smoke and mirrors.
Eeyore
bea...@gmail.com wrote:
> maur...@tpg.com.au (Mauried) wrote:
> > Eeyore wrote
> > <rabbitsfriendsandrelati...@hotmail.com> wrote:
I don't doubt it, thanks for your honesty.
The OP asked for a 1.5kW system in an area with 900kWh p.a. of insolation. He didn't
state whether he meant it to peak at 1.5kW or whether we wanted an average 1.5 kW 24/7.
Bearing in mind that this is an area with very inclement weather and often cloudy,
would you care to guesstimate the cost of such a system, with a line attached inverter
that can feed any unused electricity back to the grid ?
Graham
bea...@gmail.com
wrote:
Solar as a replacement for the grid is hardly ever an economic
proposition. If you are on the grid your first move is to reduce your
energy use as much as possible.
Solar where a grid connection is difficult, expensive or impossible is
an option that can be very worthwhile economically and practically.
The biggest problem is where a person sets out to continue an energy
wasteful lifestyle and hope that they can reduce the dollar cost of
their waste by using solar. Solar power is free, the equipment to use
it as electricity is a longways from being free.
8k for a system. Sounds about right for the industry. As a grid
connect? Well, if he has the readies and wants to give it to somebody
else that's his business. Mind you, 8K would buy a lot of energy
saving technology that will work 24/7
Eeyore
bea...@gmail.com wrote:
> Eeyore wrote:
> > beal...@gmail.com wrote:
> > > maur...@tpg.com.au (Mauried) wrote:
I agree without reservation and have made several such suggestions.
> Solar where a grid connection is difficult, expensive or impossible is
> an option that can be very worthwhile economically and practically.
Indeed.
> The biggest problem is where a person sets out to continue an energy
> wasteful lifestyle and hope that they can reduce the dollar cost of
> their waste by using solar. Solar power is free, the equipment to use
> it as electricity is a longways from being free.
Totally agreed again. This is what I call 'tokenism'.
> 8k for a system. Sounds about right for the industry. As a grid
> connect? Well, if he has the readies and wants to give it to somebody
> else that's his business. Mind you, 8K would buy a lot of energy
> saving technology that will work 24/7
Agreed on the energy saving ! He could be as snug as a bug in a rug.
Graham
Mauried
Heard an interesting side issue related to CO2 production and ETS.
Most people seem to want to do something to combar AGW, leaving aside
the issues of whether its real or not, but how many people even care
when they buy some goods at their local shop which was imported from a
country that doesnt have an ETS scheme like China.
If the CO2 emitted to produce a product that you buy was in fact
emitted somewhere else, its no longer a problem.
People only seem concerned about how much CO2 is emitted in their
country, they dont care about emissions elsewhere.
Same goes for exports.
Nothing at all wrong in exporting millions of tonnes of coal, as long
as the coal is turned into CO2 somewhere else.
Id like to know how much CO2 is produced to manufacture a 100W solar
panel.
adela
days and in winter. You might want to consider the length of payback
period so you can figure out how quickly you'll recoup your initial
investments into the PV. Most PV systems have lifetime of around 20 -
25 years but everything depends on the average number of sunshine hrs/
year in your region.
Eeyore
Mauried wrote:
> Eeyore wrote:
> >Phil wrote:
> >
> >> I've been quoted ~ £8K for a 1.5 KW PV system.
> >
> >Chances are at best that it PEAKS at 1.5kW for a couple of hours a day.
> >
> >Since you have missed out the most important data i.e. how many *kWh* you want
> >then you're going to be led by the nose up the garden path by unscrupulous
> >installers.
>
> Heard an interesting side issue related to CO2 production and ETS.
> Most people seem to want to do something to combar AGW, leaving aside
> the issues of whether its real or not, but how many people even care
> when they buy some goods at their local shop which was imported from a
> country that doesnt have an ETS scheme like China.
> If the CO2 emitted to produce a product that you buy was in fact
> emitted somewhere else, its no longer a problem.
> People only seem concerned about how much CO2 is emitted in their
> country, they dont care about emissions elsewhere.
>
> Same goes for exports.
> Nothing at all wrong in exporting millions of tonnes of coal, as long
> as the coal is turned into CO2 somewhere else.
>
> Id like to know how much CO2 is produced to manufacture a 100W solar
> panel.
These things used to be called environmental impact statements. Yes, I'd very much
like to see one for a PV panel. Funny how that data doesn't seem to be there.
BTW did you know something like 30% of all oil use is in shipping, a large part of
which is bringing those cheap Asian goods to us ! Whilst the greens fuss over the
relatively tiny 8% used in aviation.
The have amazingly myopic vision.
Graham
Eeyore
adela wrote:
> This won't work 24/7.
You mean my plan you totally snipped so I have to go back and forth to
check it ?
> It will generate a lot less kW during the rainy
> days and in winter.
I know. Just when you want it. The numbers were so absurd I didn't bother
even starting to look at that.
> You might want to consider the length of payback
> period so you can figure out how quickly you'll recoup your initial
> investments into the PV. Most PV systems have lifetime of around 20 -
> 25 years but everything depends on the average number of sunshine hrs/
> year in your region.
Total insolation is a far better measure and it's 900kWh/m2 where the OP
is. Not frankly a lot. As opposed to 2500 in some parts of the USA.
And you didn't mention how many batteries would be required to cover a
week of cloudy days either.
Graham
BobG
> Id like to know how much CO2 is produced to manufacture a 100W solar
> panel.
Let's guess the panel costs about $450 and there is about 10% profit
in there, leaving about $400 for the 'parts'... silicon wafers and
aluminum frame and glass cover, all of which use lots of electricity.
I bet 75% of that $400 is electricity... $300 or so. Thats 3000KWhr or
so. If the coal plant is 40% efficient, you need 7500KWhr thermal. I
know a KWhr is 3412 BTU and coal is about 15000 BTU per lb, but I dont
know what % of the combustin gas is CO2. Care to weigh in Graham?
Ron Rosenfeld
wrote:
Phil,
As others have pointed out, you will probably do more for global warming
and reduce your electric bill by conservation, than by installing a PV
system.
Eeyore indicated your average insolation to be about 2.5 kWh/m2/day.
You didn't say exactly where you were located, but for the area around
Aberdeen, links from here http://eosweb.larc.nasa.gov/sse/ (free
registration required) also shows similar insolation values (2.39
kWh/m2/day).
That means that your 1.5kW system (assuming the 1.5kW refers to the panel
rating) will generate about 3.4 kWh/day or maybe 105 kWh/month.
You can compare those values to your electric bill to assess whether £8K
for a 1.5 KW PV system makes sense in view of your goals, or whether you
will have any spare power to sell back to the grid.
--ron
Eeyore
BobG wrote:
You've confused me already by introducing BTUs.
You want to know the volume of CO2 released by burning 7.5MWh (thermal) of
coal ?
But a simpler estimation of environmental impact could be power taken to
manufacture vs power produced.
In this case you've estimated 7.5MWh to make the panel.
A really GOOD insolation for the panel (in the USA) would be around
5kWh/day average (parts of California) and over the quoted lifetime of 25
years, receive some 45 MWh.
At 15% conversion efficiency (about the best you can currently get), that
would produce 6.8MWh of electricity or a net LOSS of 10% over the
manufacturing energy.
Of course if it lasts longer without being hit by a giant hailstone or
killed in any other way and doesn't age too badly (after 25 yrs you can
actually expect output to be 10% down) you MIGHT eventually get in
'energy profit'.
Graham
Ron Rosenfeld
<rabbitsfriend...@hotmail.com> wrote:
>But a simpler estimation of environmental impact could be power taken to
>manufacture vs power produced.
Take a look at the paper by Erik Alsema and Mariska de Wild-Scholten,
“Reduction of Environmental Impacts in Crystalline Silicon Photovoltaic
Technology– An Analysis of Driving Forces and Opportunities,” presented at
the Materials Research Society Fall 2007 Symposium, Boston, USA, November
2007.
http://tinyurl.com/5rpwfm (hopefully one of these will work)
They calculated Energy Payback Time defined as the total energy (KWH)
required to produce the system divided by the Annual Energy Generation
(KWH/yr).
They looked at rooftop systems in southern Europe, and assumed an
irradiation of 1,700 kWh/m2/yr, and assumed a system efficiency of 75% to
account for losses from module temperature, wiring and inverter
inefficiencies.
They looked at different types of PV manufacturing technology, including
ribbon, multicrystalline, monocrystalline and thin-film.
They included not only the direct energy used to produce the system, but
also the "embodied energy" of the raw materials used in manufacturing all
the parts of the PV system.
They also included the BOS components (racks, inverters, wires, etc).
In 1975, the EPBT was about 20 years.
In 2006, the EPBT was 1.5 - 2 years depending on the type of silicon module
studied.
In looking at the reasons for the drop in EBPT from 1975-2006, they project
the possibility of further reductions in the future, perhaps to less than 1
year.
--ron
Eeyore
Ron Rosenfeld wrote:
> Eeyore wrote:
>
> >But a simpler estimation of environmental impact could be power taken to
> >manufacture vs power produced.
>
> Take a look at the paper by Erik Alsema and Mariska de Wild-Scholten,
> “Reduction of Environmental Impacts in Crystalline Silicon Photovoltaic
> Technology– An Analysis of Driving Forces and Opportunities,” presented at
> the Materials Research Society Fall 2007 Symposium, Boston, USA, November
> 2007.
>
> http://www.ipcrystalclear.info/Shared%20Documents/Project%20publications/SP6%20paper%20for%20MRS%20Fall%20Symposium%202007%20(UU,%20Alsema%20and%20ECN,%20de%20Wild).pdf
>
> http://tinyurl.com/5rpwfm (hopefully one of these will work)
>
> They calculated Energy Payback Time defined as the total energy (KWH)
> required to produce the system divided by the Annual Energy Generation
> (KWH/yr).
>
> They looked at rooftop systems in southern Europe, and assumed an
> irradiation of 1,700 kWh/m2/yr, and assumed a system efficiency of 75% to
> account for losses from module temperature, wiring and inverter
> inefficiencies.
>
> They looked at different types of PV manufacturing technology, including
> ribbon, multicrystalline, monocrystalline and thin-film.
>
> They included not only the direct energy used to produce the system, but
> also the "embodied energy" of the raw materials used in manufacturing all
> the parts of the PV system.
>
> They also included the BOS components (racks, inverters, wires, etc).
>
> In 1975, the EPBT was about 20 years.
Broadly in line with my / our rough estimate.
> In 2006, the EPBT was 1.5 - 2 years depending on the type of silicon module
> studied.
>
> In looking at the reasons for the drop in EBPT from 1975-2006, they project
> the possibility of further reductions in the future, perhaps to less than 1
> year.
So how come they need so much less energy to manufacture now ? Nanosolar isn't publishing any real-world figures so far AFAIK.
Graham
Ron Rosenfeld
<rabbitsfriend...@hotmail.com> wrote:
>So how come they need so much less energy to manufacture now ? Nanosolar isn't publishing any real-world figures so far AFAIK.
I don't believe they included any data from the proprietary Nanosolar
process in their analysis of 2006 data.
They credit improvements in
Silicon consumption (reduction)
Energy input in silicon feedstock production
Cell efficiency
Energy efficiency in casting and other process steps
--ron
do...@40.usenet.us.com
> At 15% conversion efficiency (about the best you can currently get), that
> would produce 6.8MWh of electricity or a net LOSS of 10% over the
> manufacturing energy.
There are studies from good sources that put the energy payback at 2 to 4
years. Just a few, in alphabetical order:
http://www.clca.columbia.edu/papers/Fact%20Sheet_EnergyPayback.pdf
http://www1.eere.energy.gov/solar/myths.html#6
http://www1.eere.energy.gov/solar/pv_basics.html
http://www.nrel.gov/docs/fy04osti/35489.pdf
http://www.nrel.gov/docs/fy99osti/24619.pdf
http://www.worldenergy.org/publications/survey_of_energy_resources_2007/solar/723.asp
--
Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5
Mauried
<rabbitsfriend...@hotmail.com> wrote:
And herien lies an interesting conundrum.
The introduction of ETS around the world is intended to increase
artificially the cost of electricity thats produced by polluting power
stations like coal.
The intended consequence is that electricity produced from renewables
like solar and wind will then become more attractive.
However, the above assumes that the costs of producing solar panels
and building wind generators themselves dont also rise.
Solar panels need lots of electricity to make , and wind generators
need lots of iron and steel and concrete.
Currently, all the worlds existing Solar Cell manufacturing plants are
powered from the grid , not from renewables.
Making iron and steel and concrete is also an intensive CO2 emiiting
process.
If CO2 is taxed at say $20 a tonne,what will be the price increase in
the costs of solar cells and windmills.
I betcha no one knows , because it hasnt been thought thru properly.
Eeyore
Mauried wrote:
> Eeyore wrote:
> >BobG wrote:
> >> Mauried wrote
> And herien lies an interesting conundrum.
> The introduction of ETS around the world is intended to increase
> artificially the cost of electricity thats produced by polluting power
> stations like coal.
> The intended consequence is that electricity produced from renewables
> like solar and wind will then become more attractive.
> However, the above assumes that the costs of producing solar panels
> and building wind generators themselves dont also rise.
> Solar panels need lots of electricity to make , and wind generators
> need lots of iron and steel and concrete.
> Currently, all the worlds existing Solar Cell manufacturing plants are
> powered from the grid , not from renewables.
> Making iron and steel and concrete is also an intensive CO2 emiiting
> process.
> If CO2 is taxed at say $20 a tonne,what will be the price increase in
> the costs of solar cells and windmills.
> I betcha no one knows , because it hasnt been thought thru properly.
I'm sure that's right.
BTW, on an unrelated topic, can the general public or business send typical
size small or large parcels by rail in Australia ? I'd have though your network
was a bit limited. What's the preferred option ?
Graham
Ron Rosenfeld
>If CO2 is taxed at say $20 a tonne,what will be the price increase in
>the costs of solar cells and windmills.
>I betcha no one knows , because it hasnt been thought thru properly.
The study that I cited in my response to Eeyore has some CO2 emission
information. It is presented in terms of grams per kWh generated for an
entire system. So it seems that the data is available (but not directly in
this study) to come up with appropriate values.
At present, for a multicrystalline silicon roof-top PV system in southern
Europe, as defined in their paper, they estimate 30 g/kWh generated. Since
they define the irradiance, life span and system efficiencies, one should
be able to do the math to figure the amount per kWp.
However, they include the emissions from the electricity generation, and
indicate that with a switch to "green" electricity, the emissions would
decrease by about 1/3. (There is a US plant set up recently which is
generating their power from PV, so using green electricity is clearly a
possibility).
Also, their data includes the CO2 production for the entire system, and not
for just the PV panels.
IF I've done the math correctly, and not misplaced any decimals, it appears
as if the extra cost would be no more than $0.03USD per watt. Current
pricing is about $5.00USD per watt
But check my math:
1 kWp at 1,700kWh/m2/yr for 30 yrs --> 51,000 kWh
30 gm/kWh --> 1.53 tonnes CO2
$20/tonne --> $30.60 per kWp or $0.0306 per Wp
And assuming that a percentage of this is related to nonPV parts of the
system, the actual increment would be even less. But I also left out
efficiency issues, which would increase the number a bit. (They claimed an
efficiency of 75% for the "entire" system; but the value for just the PV
part would be better).
They estimate that future developments (and yes, I know it is difficult to
make predictions about the future), should reduce the CO2 emission to 15
gm/kWh, and switching to "green" power further reduce it to maybe 10
gm/kWh. And again, these numbers include the racks, inverters, wiring, etc
which would be subtracted if the PV mfg were paying the CO2 tax.
--ron
BobG
wrote:
> You've confused me already by introducing BTUs.
And I thought I was being a politically correct Yank by speaking
British Thermal Units to the English guy.
Eeyore
BobG wrote:
> Eeyore wrote:
> > You've confused me already by introducing BTUs.
> ========================================
> And I thought I was being a politically correct Yank by speaking
> British Thermal Units to the English guy.
They should be called American Thermal Units now. We don't use lbs and
deg F here anymore or whatever BTUs are.
We use Joules (and Watts in place of BTU/hr) instead.
Graham
bea...@gmail.com
wrote:
At some time in the (far) future the US will give up having two
standards, Si units in the lab and imperial for the plebs. Just don't
hold your breath.
Mauried
Nope, it all goes by truck.
Rail is essentially only used for Container loads.
Calvin
> And I thought I was being a politically correct Yank by speaking
> British Thermal Units to the English guy.
I'm afraid it is HIGH time that the USA was dragged (kicking and
screaming all the way I'm sure) into the twenty-first century and
starting using SI instead of the current abortion of a measurement
system they have - a hotch-potch of archaic imperial units and others
that they plain 'made up' and then add to the confusion by giving them
the same names as the old imperial units they replaced !
Calvin.
Brisbane Australia (a country that had the good sense to adopt SI 34
years ago)
PS: When the day comes that they does use SI in the USA the unit of
measure is the 'METRE' NOT meter !
Eeyore
Mauried wrote:
> Eeyore wrote:
> >Mauried wrote:
> >
> >BTW, on an unrelated topic, can the general public or business send typical
> >size small or large parcels by rail in Australia ? I'd have though your network
> >was a bit limited. What's the preferred option ?
> >
> Nope, it all goes by truck.
> Rail is essentially only used for Container loads.
I imagined so. You don't have that many rails lines outside commuter areas do you ?
The question was inspired by a twit in another group who reckons *all* freight
should travel by rail. He doesn't seem to realise that such a thing has been in
continual decline for decades. No rail parcels service exists in the UK any more
either.
Graham
Eeyore
Calvin wrote:
I doubt they'll ever change that one any more that start writing theatre
instead of theater.
Graham
bea...@gmail.com
wrote:
Actually there is still a rail parcel service in OZ. Of course you may
never receive what was sent.
bea...@gmail.com
wrote:
Nah, you poms will just have to learn to speak merkin.
Look it up. You will never see the US the same way again.
T. Keating
>Eeyore <rabbitsfriend...@hotmail.com> wrote:
>> At 15% conversion efficiency (about the best you can currently get), that
>> would produce 6.8MWh of electricity or a net LOSS of 10% over the
>> manufacturing energy.
>
>There are studies from good sources that put the energy payback at 2 to 4
>years. Just a few, in alphabetical order:
>
>http://www.clca.columbia.edu/papers/Fact%20Sheet_EnergyPayback.pdf
(1 page paper.. for europe )
>http://www1.eere.energy.gov/solar/myths.html#6
(no specific references, ref one workshop paper)
>http://www1.eere.energy.gov/solar/pv_basics.html
(better, references material presented in 2006 )
>http://www.nrel.gov/docs/fy04osti/35489.pdf
(somewhat dated.. references 1991 to 2000.)
>http://www.nrel.gov/docs/fy99osti/24619.pdf
(some what dated.. 1999 report..references 1991-1998)
>http://www.worldenergy.org/publications/survey_of_energy_resources_2007/solar/723.asp
(References not included. assumptions too conservative.. 25 year
lifetime?)
Studies usually fail to include.
Using optimal locations instead of national average solar flux.
(2 to 3x output improvement)
Single or Dual axis tracking.. (instead of fixed angle mounting..
~40% output improvement)
Recycling.. (Virtually nothing is consumed during operation. 3 to 4x
improvement in EPBT)
Extended service lifetime. (I've got Solar panels that are still in
service after 30 years.)
Overall effect reduces EPBT to well under a year.
BobG
> I'm afraid it is HIGH time that the USA was dragged (kicking and
> screaming all the way I'm sure) into the twenty-first century and
We're almost there... we use decimal inches instead of 1/8ths and
1/16ths and decimal miles instead of furlongs. However, resurveying
all of North America, which is conveniently divided into range,
section and township based on miles and acres will increase
productivity how again?
David Williams
-> 1/16ths and decimal miles instead of furlongs. However, resurveying
-> all of North America, which is conveniently divided into range,
-> section and township based on miles and acres will increase
-> productivity how again?
Much of Ontario, which is in North America, was surveyed with a grid
that was ten furlongs on a side. Back then, the Brits (unlike the Yanks
who had already gone their separate way) were trying to rationalize the
Imperial system to make it use multiples of ten, like the metric
system. So an Imperial gallon is the volume of ten pounds of water, a
furlong is ten chains, each of which is 100 links, an acre is 1/10 of a
square furlong, and so on. The furlong was intended to be the main unit
of distance, and the fact that it is almost exactly 200 metres gave a
handy cross-link between the two systems.
So main roads in Ontario, including here in Toronto, were laid out ten
furlongs apart. Now that we use the metric system, the distance between
them is almost exactly two kilometres, which is handy.
dow