Letters to the Editor
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"Held hostage by the sun states"?
Even in New York state, people install solar panels on their roofs. Sure, southern states have more sun exposure, but northern states have plenty, too. There is no reason not to convert that energy to electricity.
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Salim
I lived in Albany for 4 years. It was sunny maybe 25 days a year. Maybe. And crowded northern states don't have affordable land prices to erect massive arrays.
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586 square miles?
seems to me we have got to have about that much space in wasted desert out in the south west.
Certainly, there are the practical problems in the creation of solar pannels as was discussed, but it seems like we really are wasting a great deal of space not paving over large chuncks of American desert and putting up solar farms.
Of course the biggest problem with solar is the realization that we are only at the start of the field, and massive investment in solar will likely only guarantee it's own obselecance in a few decades, but without such investments it's likely we may not develope solar as quickly and efficiently as we could.
So perhaps it is a good idea if the US goverment started wasteing money on Solar, and turn death valley into a power plant. By creating a gauranteed market for solar, you will likely infuse a great deal more inovation into the creation of newer, better, smaller, and more efficient panels.
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Short and sweet
Pablo Päster's article is short and sweet, while also being long on good, hard basic research.
Is "Ask Pablo" going to start being regular at Salon? So far I'm sold on style. And Päster's general conclusion — that diversity of power generation is a good idea — is correct.
However there's one place where his analysis falls flat on its face: scale. Five hundred eighty six square miles is tiny, and so is a billion metric tons of silicon.
For one thing, the Earth is predominantly made of silicon. It's one of the few substances about which we can safely say that, indeed, the world won't ever run out — because to do so would be to run out of world. If we want to extract and process 5 times what we do now, we can probably achieve that in half a decade — or less, if we want to spend the money (hint: it's either that or build a continent-sized levee around Asia, your pick).
Secondly, 5 square meters per person is smaller than most people's roofs. Assuming lossage due to small scale and fixed installation base, and factoring in multiperson dwellings, even at 25 or 30 square meters per household you're still talking rooftop installations. Even if the relative efficiency of surface per capita in apartment buildings gets you, you've massively cut down on the additional land use necessary for complete solarization, and you're still just using the existing built environment.
With PV material now commercially available that basically has the same properties as roll-roofing, that's the first and most obvious place to start solarizing. Plus as we scale up the problem — ever-expending population and construction — we scale up the solution base, which isn't (as) true for even other renewable sources.
I'm not a huge "solar uber alles" person, but it seems clear that Päster's conclusions regarding solar power need re-examination.
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@Amity
But Pablo is off by a factor of 10; it is 6000 square miles not 600. And that makes his estimate of how much silicon processed into semiconductor material off by the same amount. He is right to have doubts about processing even the smaller amount. What is the environmental impact of processing the larger amount?
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WHZ on fast fact checking
http://www.solarbuzz.com/Consumer/FastFacts.htm
But not too fast, please! I didn't even catch the author's mistake. Oops!
1366 watt per square meter arrive from the sun at the top of the atmosphere ... yields 1502.6 watt hours/ square meter or 1.5026 kilowatt hours per day for a 1 meter square panel
So going with your math, let's say that that Päster is "merely" off by three orders of magnitude. So we would need 30-something-odd times as much ground surface area as he estimates. (Yeah, yeah, still assuming a fairly ideal case — but also assuming no improvements in the efficiency of PV, which is a losing bet. So let's call it even.)
Rooftop conversion still takes a big bite out of that, and in particular makes one of the more egregious liabilities of our culture's building habits — large building-surface-to-occupant ratios — into an asset.
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@Amity again
Pablo is just off by about a factor of ten, assuming prime south west sun territory. If you want to do this in upstate NY, it would be more than a factor of thirty.
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Mike Sulzer on impact
What is the environmental impact of processing the larger amount?
Fair question, and I'm thinking too fast and calculating too slow today, so forgive my earlier enthusiasm. I appreciate the correction.
One could argue that a "do no harm" approach is the only ethically correct one to take in assessing environmental impact. I'm not sure that's realistic, though — or even possible. Given a choice between, say, extracting oil from the ground to power a system that will require more oil later on, versus extracting silicon from the ground to construct a system that will require only a little silicon to maintain, I'd go with the latter any day of the week.
As for the various other transition metals that are also part of PV technology, that's another matter. But even in that case, we know how to do remediation — we just generally choose not to. Intuitively the idea of zero-sum choices in renewable energy is suspect — so often those issues come down to questions of resource allocation and cultural resistance.
And in terms of ability to move the bulk amount, a crash program to have enough extractive capability to meet whatever need we can reasonably conceive in 5 or 10 years can't cost more than we're spending in Iraq. Even ten million tons of something pales in comparison to multiple trillions of dollars.
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Don't forget concentrator systems
You don't need to use all that much silicon in a photovoltaic system. For example a Swedish company, Arontis, is working on a system that uses parabolic mirrors to concentrate sunlight onto a much smaller, cheaper photovoltaic array. Of course this means that the array has to be cooled, but this is done with a simple water-cooling system, and useful heat can also be extracted from the cooling water. Win-win.
I'm not advocating putting all our eggs in the photovoltaic basket, but the costs CAN be reduced with simple, clever solutions.