Found an independent estimation here: http://www.investorvillage.com/smbd.asp?mb=2234&mn=5759&pt=msg&mid=291858 "1 gigawatt of CIGS solar cells = 5 tons of each metal (very rough estimate)"
That's 20e6 g of CIGS for 1e9 W, i.e. 20e-3 g/W = 0.02 g/W (I had guesstimated 0.01 g/W) Michel ----- Original Message ----- From: "Michel Jullian" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Monday, December 17, 2007 11:26 AM Subject: [Vo]:Re: Nanosolar has started production > The CIGS ink particles are even nanometers thick it seems: > http://www.nanosolar.com/nanoink.htm > "A key advantage of the ink is specific to an idiosyncracy of the CIGS > semiconductor: Because it > consists of four elements which have to be in just the right atomic ratios to > each other, the ink > serves a useful purpose by effectively "locking in" a uniform distribution > ("by design"). The > homogeneous mix of nanoparticles in the ink in just the right overall amounts > ensures that the > atomic ratios of the four elements are correct wherever the ink is printed, > even across large > areas of deposition." > > Something puzzles me in the above BTW, they seem to suggest the four elements > are not mixed at the > particle level but at the ink level... could this mean that each nanoparticle > is either Cu, In, Ga > or Se? If this is the case one can easily believe their production costs are > low, as even the > nanoink material wouldn't cost much to process! > > Anyway back to Michael's question, we can estimate that the particles are at > most 100nm in > diameter (otherwise they wouldn't qualify as 'nano'), so worst case CIGS use > is 100e-9 m^3 per > m^2. Density being less than 10g/cm^3 = 10e6 g/m^3, that's less than > 100e-9*10e6 = 1g/m^2. > Assuming 10% efficiency (100W/m^2) they use 0.01g of CIGS per watt at most. > > So, if my calculation is correct, even at $1000/Kg = $1/g the cost of the > active material would be > 1 cent per watt at most, i.e. less than 3% of their rumored 30 cents total > cost per watt. > > Michel > > ----- Original Message ----- > From: "Robin van Spaandonk" <[EMAIL PROTECTED]> > To: <[email protected]> > Sent: Monday, December 17, 2007 8:32 AM > Subject: Re: [Vo]:Nanosolar has started production > > > In reply to Michael Foster's message of Sun, 16 Dec 2007 15:56:49 -0800 > (PST): > Hi, > [snip] >>I hope they succeed at what they are doing. I am concerned that I cannot find >>how much indium and gallium they use either per square meter or per watt. The > > It can't be much, because as I remember, the film is only microns thick, which > is why they can print it on. > [snip] > Regards, > > Robin van Spaandonk > > The shrub is a plant. > >
