In the sun

When you think of solar power, you probably think of solar panels on your roof, or those little solar cells on your calculator. But it doesn’t have tp be that high-tec. In concentrated solar power schemes, you simply find a large area of land in the middle of a sunny area (e.g Arizona, Spain, Australia…) and equip it with lots of mirrors that focus the sun’s light ono the top of a tower, through which you pipe water. The heat converts the water to steam, which drives a turbine, and generates electricity.

There are a number of these schemes areound the world, such as the 11 megawatt plant near Sevilla, in Spain. This has 624 mirrors, each of 120 metres squared in area. ONe major advantage of this kind of power is that steam is relatively easily stored – you can generate it when the sun is shining, but delay feeding it to your turbine until electricity demand is highest. With silicon solar cells you can’t do that so easily – you need to store the electrical energy somehow.

The Sevilla plant has had a lot of European Union subsidies behind its construction, but now operates on its own, as a fully commercial unit. THe history of government subsidies in solar power worldwide is quite interesting. THere was major investment at the end of the 1970’s as tensions in the Middle East threatened the supply of cheap oil. But in the late 80’s, as the oil price fell, so did the subsidies, and trajically so did many of the innovative companies that had been built on these subsidies. In the 90’s, with cheap oil, major market incentives were required to get research back into solar power.

Since then, until very recently, the price of oil has been climbing rapidly, and so has interest in solar power. The question now is, with the fall in oil price, will investment follow suit again, or have governments learned from their mistakes. The cynic in me says that’s wishful thinking, but for the sake of the planet I hope I’m wrong.

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