I agree cost per watt matters more than eficiency, with the type of use they are promoting (utility scale plants on low cost land outside cities, their first installation in Germany is on a reclaimed landfill). They claim an energy payback time of a few months, and a lifetime of decades. Of course, all we know for now is what they claim, which may or may not be accurate. If it is, it is quite good indeed.
Jones's concern about the price and availability of indium and gallium should be temperated by the fact that the amount required per watt is very small. An estimation was posted here some time ago, IIRC it concluded this was not a problem. If it was, I guess not so many manufacturers would jump on the CIGS bandwagon, or the LCD screen bandwagon for that matter. Which doesn't mean there are no better possible clean energy solutions than CIGS PV of course. Michel ----- Original Message ----- From: Jed Rothwell To: vortex-L@eskimo.com Sent: Monday, March 17, 2008 10:29 PM Subject: Re: [Vo]:Nanosolar efficiency 9-10%, installed cost $3/W Michel Jullian wrote: >9 to 10% efficiency for Nanosolar's current production (they target >15% ultimately). Installed cost of 1MW German plant panels $3/W. If they really can achieve $3/W, perhaps despite the problems described by Jones Beene, than this would be a remarkable breakthrough. This is $3000 / kW which is cheaper than wind turbines, nuclear or hydroelectricity. I think only gas and coal have cheaper installation costs, and of course they require fuel over the life of the plant. A higher percent of efficiency improves the cost per watt, but other than that it doesn't matter. In other words, it would be better to make it 5% efficient for $200 per square meter than 10% efficient for $500. For most applications, you can always take up more space. (There are some apps, such as roadside collectors, in which a small, compact collector is an advantage.) To put it another way, collection space is usually cheaper than the cost premium for higher efficiency. At least that's how it worked out a few years ago when I checked the numbers. Ed Storms first pointed this out -- on this forum, I think. Another critical issue with PV is how quickly they degrade over time. Many years ago, the half-life was something like 5 or 10 years as I recall, and the energy payback time for some types was infinity. That is to say, they never generated as much energy as it took to fabricate them. They were useful only as a sort of "storage battery" that you could deploy to a remote location. You can think of it as transferring energy from the factory to the remote site. I think the energy payback time has improved considerably. PV is still growing by leaps and bounds in Japan. Here is a solar-thermal plant installed in Arizona last year, for $6,000 / kW of capacity, which is a promising number: http://www.renewableenergyworld.com/rea/news/story?id=44696 - Jed
