Sunday, August 08, 2004

More Good News

Apparently, there is a solar power boom worldwide, but especially in Germany (where, while elsewhere sceming against wind power - as wind reached a level threatening to conventional quasi-monopolies, the lobbyists started to work overtime -, all parties agreed to raise mandatory feed-in tariffs for photovoltaics).

Last year was a record year, with 145 MW generating capacity added (almost twice of what was added in 2002), pushing the German total to 417 MW. For this year, the industry expected 200 MW, but last week they raised the number to 330 MW - an even higher growth only limited by the fact that factories are working at full capacity, and companies are scrambling to accelerate construction of more assembly lines. At this rate, world leader Japan (887 MW total at the end of 2003 after adding 219 MW) is not far away. And once capacity reaches demand again, the economies of scale, as well as the increased budget for R&D enabled by the increased income, plus competition will surely lead to significant cost reductions.

Worldwide, additions of 744 MW pushed the total to 3120 MW; with until-the-nineties dominant USA still in third place behind Japan and Germany, but for the first time with falling production. As one facory was closed in California, maybe Arnold Schwarzenegger took notice, and that's why he is said to be about to implement some of his election promises regarding solar-favoring house construction and better feed-in possibilities.

However, for comparison: a 1000 MW nuclear power plant block, which mostly runs at full capacity, produces 8 billion kWh a year - that's 8 kWh per Watt. An average 1.5 MW wind power plant on land, which on average runs on a fourth of full capacity, generates 3.75 million kWh per year (those on a seashore more, up to 5 million) - that's 2.5 kWh per Watt. And an average 150 W solar module on a Central European rooftop, with its energy yield a function of day and night and clouds and summer and winter, produces 150 kWh a year - that's 1 kWh per Watt. In other words, the end-of-2003 German capacity would still just replace one-twentieth of a modern nuclear block.

In other words, still a long way to go.

However, I have reason to think an even bigger boom is not far away - the reason is the development of multi-band solar cells on film. Current solar cells, those familiar blue silicon chips in glass, are heavy, unwieldy, on some buildings an eyesore, and have a photovoltaic efficiency (that is, how much of the incoming light they convert to electricity, NOT the previous stuff about non-ideal sunlight exposure) of 13-18% (and a module efficiency of 10-14%).

However, multiband cells in development will push that to 50%, so that a family home rooftop will be enough area for solar cells to work not just as backup, but (with the help of a storage battery) will be able to carry the full load and more - and on film, they can be formed into various shapes, plus colored to some extent (they obviously have to be dark) according to taste.


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