[ExI] Some thoughts on the ecopocalypse - the argument for domestic ground based solar.

[Eugen Leitl]

On Sat, Nov 28, 2009 at 12:19:51AM +1030, Emlyn wrote:

> The good thing from an economic point of view with domestic solar, is
> the short innovation period, and that consumers will buy it multiple

It throws a monkeywrench into the ROI calculation, because
the costs are still high http://solarbuzz.com/ and because
the lifetimes are so long (25-35 years). You have to anticipate
the future energy prices, and the price decay. Exponential
decay was there for a long time, until sudden demand (thanks
to subsidies) made markets explode. This year almost 3 GW
capacity will be installed in Germany, and you just can't buy
an inverter, nevermind hire a crew to install the system.

Right now lowest thin film module price is 1.76 USD/Wp, consider
the price could be below 1 USD/Wp in a couple years (assuming
inflation-adjusted value, of course). If you pay 12-25 kUSD
just for the panels this is going to make quite a difference, so
many people will wait. Sooner or later it's worthwhile, for
me when the price of electricity from my roof falls a bit
below 0.15 EUR/kWh, or so. 

> times. So say you have a few thousand bucks for PV that almost
> provides all your power needs, and people buy that, then a couple of

Right now Wp is pretty good, but consider that most are retrofitted,
and you still need a grid-tied inverter (most installations are not
insular, there you can use cheaper inverters but have to consider
solar batteries for nighttime buffering). 

> years later you have it for a similar price that provides all your
> needs plus half again, then some of the same people will buy that,
> then a couple of years later half the price, twice as good again, the
> same people will buy it again, and so on. That's the financial driver
> for exponential improvement. Hopefully there's a similar enabling
> technological approach to help keep up with demand. eg: if we use the
> same kinds of technologies to print the panels or roof tiles or what
> have you, that we use for fabbing chips. Is that plausible?

The current technology does a lot better than semiconductor, current
CIGS nanoink is printed on top of aluminum foil at m/s^2 rates. Expect
huge advances from that area, including processivity and price, as well
as durability. There's no obvious floor for Wp price, especially if
you have self-growing panels.

-- 
Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org
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