Solar Comments And Computations

The rise of thin-film solar power
Leaner and cheaper
The future of solar power is not only bright but also thin
See article Oct 22nd 2009 | Washington, DC

Readers' comments
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Rený_1 wrote: Oct 23rd 2009 7:28 GMT 'But the gap between solar and conventional power sources is becoming, well, thinner.'

*Prof. Dr. Hermann Scheer says, 'My advise to all governments, to all companies including the conventional power companies; Do not make any large investments in conventional energy, it will become stranded investments within the next decade.'
(3:17min, Here Comes The Sun, VPRO Backlight)

*General Chairman of the World Council for Renewable Energy (WCRE); President of the International Parliamentary Forum on Renewable Energies; Member of the German Bundestag.

phylarchus wrote: Oct 23rd 2009 7:40 GMT Instead of concentrating on rare, highly poisonous and expensive raw materials (such as Cadmium, Indium, Selenium e.o.), research in my opinion should remain focused on cheaper and more user-friendly elements such as Carbon, Silicium, Aluminium, Germanium, Tungsten (Wolframium), Titanium, Rare Earths etc. It should not be forgotten, that a product is intented, which will be widely applied and massively used.
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TGoby wrote: Oct 23rd 2009 8:35 GMT Great piece. I'm all for solar, but would love to see the Economist's take on nuclear. Given ONLY the facts, and not irrational fears, nuclear seems to be a nice solution to the most obvious problem our world faces.

I read tons of articles on renewable energy, day after day, and yet am always left pondering the same frustrating question - the technology is so clearly there to power this world on clean energy (PV, thin-film, solar thermal, nuclear, hydro, wind, geothermal, ocean, etc.) - why isn't it being disbursed/installed at a more rapid pace? is it money? is it political interests?
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Ismael X wrote: Oct 25th 2009 6:21 GMT Just few facts.
World electricity demand every year: 17,000 billions KWh.
World global energy demand every year (electricity + transport, heating and other use fuel): around 30,000 billions Kwh (this is a figure we must take into account if we really want to switch to electric cars and transport).
Electricity produced by a 1 square meter PV silicon panel: 110-150 KWh.
Electricity produced by 1 square meter of thin film: 55-75 Kwh.
Silicon panels (1 m2) required to cover 10% of world energy needs: 200-270 billions (yes: BILLIONS, 200-270,000,000,000 and yes: just for 10% of our needs)
Square meters of thin film required to cover 10% of world energy needs: 400-540 billions (400-540,000 square kilometers: the size of countries like France or of a couple of states like Wyoming and Utah together, and again yes: just for 10% of our needs).

Photovoltaic solar energy might even fall down to ridiculous prices but as long as it doesn't show the capability to propel an immense scale up in production (i.e. use the cheapest, widely available materials and easieast to use technologies) it will be just a niche form of energy that will cover just bits % of world energy needs.
Even if the solar industry DOES come up with rock bottom prices and mass production, it's absolutely unlikely it will answer more than 5-7% of our growing needs.
Grim numbers like those can be made for solar thermal or wind (with better outcomes, of course, but not enough better).

The enormous energy hunger of our civilization makes really unlikely for the whole bunch of hydro, solar and wind gears to give us more than 30% of our needs in 10-20 years (if all the good stars in the sky shine for them).
The conclusion is simple.

Either we seriously push for a vast, uncompromizing nuclear choice heading strongly (i.e. put money in the pot) for the IV generation machines, or the future will be fossil, fossil and again fossil. Not these days' fossil, but tomorrow's fossils, more and more difficult (and expensive) to dig out, more and more dirty for the environment, more and more lethal for our climate.
And when Siberia permafrost melts... bye bye baby. The game will be over and we'll just have to sit and wait for the next civilization archeologists to come and dig out our ruins and bones.

Hurrah for all the antinuke so-called enviromentalists. The biggest tribe of idiots in the world.

I'm sure every wise oilman in this world secretley loves them. They're his best life insurance, and our worst curse.

Ismael X wrote: Oct 25th 2009 6:25 GMT The pv panels output is on a year scale.
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View from Gorey wrote: Oct 25th 2009 11:28 GMT sorry, thin films are half as efficient, but a third cheaper. so they are relatively more expensive (.5/.67<1)
what am I missing?
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Power Engineer wrote: Oct 25th 2009 11:59 GMT It would be more accurate to say “2 GW….that’s enough to power 30 million homes 10% of the time” as solar power with its intermittent 10-15% capacity factor will not ever be able reliably power even a single home (not even 2 GW worth).

This low capacity factor dominates the solar kwh cost calculation. Recent residential and commercial solar installations cost $10,000 per kw which translates to 20 times the cost per kwh of a nuclear plant.

I applaud the remarkable cost reductions of the solar industry, but they do not change its cost disadvantage. Even if the solar cell is free, the 24/7 reliable nuclear plant has a four fold cost advantage over intermittent solar.

More importantly solar requires CO2 emitting backup which will make it impossible to meet the 80% CO2 reduction envisioned by 2050 thereby spiking the price of CO2 emission rights.

The smart grid, off peak electric autos, and more efficient A/C will flatten the load curve and reduce the limited value of solar as peaking capacity. It is more likely that solar investments will become stranded as customers and governments become weary of the large subsidies, loss of jobs, and growing government debts.
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C L W wrote: Oct 27th 2009 12:48 GMT I do not follow the math around "10%".

30,000 billion kWh annual demand
55-75 kWh per m^2 of thin-film

30,000/55 = 540, 30,000/75 = 400

400-540 billion m^2, or 400-540,000 km^2, seems to satisfy ALL demand, not 10% of demand

Assuming higher efficiencies over time, and higher insolation in strategic locations like Death Valley, Sahara etc. (infrastructure aside, and that's a big if), perhaps we can hit more than 110-150 kWh for silicon today. Maybe 300 kWh?

At that point, 100,000 km^2 is the size of Kentucky, and if you place that in the Sahara, it seems conceivable that you could possibly power the world on solar in 30 years? Or surely, a significant percent of it?

See "Electricity Without Carbon", Nature, 14 Aug 2008. Article make similar claim that <10% of Sahara covered in PV can theoretically satisfy entire world primary energy need.

Voice Of Reason wrote: Oct 27th 2009 1:49 GMT CLW wrote: "At that point, 100,000 km^2is the size of Kentucky, and if you place that in the Sahara, it seems conceivable that you could possibly power the world on solar in 30 years? Or surely, a significant percent of it?"

Hmmm. They can't even get permission to build a stinking demonstration plant in Death Valley - the likelihood of covering hundreds of thousands of square miles of "green" desert is next to nil. And if you think Saharan Africa is the place, then why even bother? Guess where OPEC's stomping grounds are located? Is switching dependency from oil/gas to solar any better? No. Especially when the costs is multiples higher. And sub-Saharan Africa is incensed about the idea of being forced to use high cost power when their economies are typically those that can least afford it.

And don't forget that typical panels see about 1% annual efficiency decline (and more if not cleaned regularly). And add in the fact that solar cells lose about 0.5% efficiency per degree C above 25C (77F) and there will be substantial loses in hot places like the Sahara that has between 32-43C (90-110F) average daily temps deserts, so will lose anywhere from 3.5% to 9% efficiency. Yes, they may gain more due to high sunlight, but the net gain isn't as much as one would expect.

The likelihood of seeing substantial solar power in our future is very low - it simply isn't cost effective to invest in such an inefficient technology when far there are far greater societal needs that would not get funded (health care etc).
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Michael Dunne wrote: Oct 27th 2009 9:28 GMT Although it is well written, I hate to say this but the article seemed a bit light and pushing a point of view that could either be backed up or critiqued by facts. judging from the comments below, its seems I am not the only one to have this perception.

It would have been nice to see a price performance chart comparing the various solar technologies, as well as against gas, coal, and nuclear (even a nuclear with full fuel cycle costs thrown in).

Also, it would have been nice to see a chart comparing relative efficiencies of solar technolgies (I believe it is in percent of light converted into electricity) over time.

I wouldn't have been too hard either (not for a periodical that usually has some pretty good charting).

I bet aside from unique off grid circumstance (say remote places in the third world) or specialized applications (like panels for emergency phones in the desert) solar may be a ways off.

What is good is that a focus on this type of materials science is taking place. Hopefully it could yield improvements like those witnessed with moore's law with integrated circuits with semiconductors. I would also be nice to see that materials science focus get placed on superconductors, batteries and fuel cells.
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palynka wrote: Oct 27th 2009 3:48 GMT Concentrating solar energy production in isolated, desert-like areas raises huge problems of distribution and storage. We need solar to be cheap so we can install it everywhere, from rooftops to roads, not gigantic solar power plants.
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Djon wrote: Oct 29th 2009 5:57 GMT View from Gorey,

You wrote "sorry, thin films are half as efficient, but a third cheaper. so they are relatively more expensive (.5/.67<1)
what am I missing?"

You appear to have missed that the "third cheaper" was based on comparing thin film and crystalline panels with equal power output, not on comparing panels of equal surface area - the exact wording in the article was "but a third cheaper, watt for watt.".