Saturday, February 27, 2010

Solar Update

I have shown that solar power simply isn't cost effective without substantial subsidies. In a guest post last year, reader O Bloody Hell showed why solar power -- particularly photovoltaic (PV) cells -- were unlikely to be a significant energy source for the foreseeable future (especially given the land-use required, see page 38).

Craig Hunter, Vice President and General Manager of Energy Technologies at Intermolecular -- which specializes in semiconductor and solar R&D design and testing -- concurs in Greentech Media:
[T]he litmus test for any solar energy technology is its ability in the next 10-20 years to be deployed in hundreds of gigawatts per year, delivering electricity at $.05-.07/kWh, even in areas that aren't very sunny. Given the load factors of PV installations, not to mention the possible need for storage, we need to consider a target installed system price of no more than $1/Wp.

Panel prices have indeed come down significantly, but the PV "experience curve" (15% cost reduction for each doubling of production) is too slow, requiring us to get to 40-80GW per year production just to reach sub-$1/Wp panel pricing. And unless we see disruptive improvements in conversion efficiency, the "balance-of-system" costs (i.e., all the system costs other than the solar panel itself) will make it impossible to achieve a $1/Wp system price even if the panels are nearly free.
Personally, I'm agnostic about whether a technological breakthrough might make non-PV solar power significant in the long term. But I'm sure that distorting subsidies are wasteful and unnecessary--the free market responds automatically to shortages and can be counted on to solve any energy crisis. Without subsidizing what might be dead-end technologies such as PV.

(via FuturePundit)


OBloodyHell said...

Any solar system which does not address the low areal density issue for solar energy is a dead end waste of money for the general usage case.

I don't give a rat's patootie if it's made of sand and nothing else, you're still going to have to cover a substantial portion of an entire state with it to get a significant degree of power from it.

And let's face it, it's not going to be just "sand and nothing else" -- it's going to be notably more expensive than that, both environmentally and human labor/timewise, not least because of the massive amount of areal coverage absolutely required means you need to set the stuff down somewhere, even if it's on the rooftop of every home and commercial facility in the southern USA...

To that end, as I touched on back then, the only two systems I'm aware of which have any real chance of being more than a piddle in the ocean is Ocean Thermal (OTEC) and Solar Power Satellites(SPS). Both of those involve substantial engineering development requirements and, in the latter case, substantial startup costs in addition, and so have no rational place in current short-term (10-20 yrs) forecasts or planning.

I think OTEC has some interesting promise, but it's not something anyone is putting substantial R&D funding into, and it may not be functional no matter what, as it does require a noted development in low-differential conversion efficiencies (that is, getting usable power from a situation where the temperature difference is low, not high).

We currently don't know how to do that very well.

More critically, we don't know if it is possible to do it very well.

Such a breakthrough isn't on the order of E=Mc^2, but neither is it particularly trivial, either. All existing known mechanisms from deriving electricity from temperature differentials -- even Johnson's JTEC -- require substantially higher temperature differences than the ocean surface -vs- depths provide to produce substantial efficiencies in power production. We can make it work now, "kinda", but not very effectively. Hell, it could be done, and was, back in the 1920s.

Marc said...

And who's going to dust the things?

OBloodyHell said...

> And who's going to dust the things?

Less facetious than you think. If they aren't cleaned it does substantially reduce their effectiveness.

And what's the second leading cause of accidental death in the USA behind auto accidents?

Right. Falls. As in "Up on the roof cleaning out the gutters" or "Up on the roof cleaning off the panels".