Wednesday, February 07, 2007

What happens when it rains?

Also in the Guardian, Katherine Hamnett gets very, very excited about concentrated solar power as a source of clean energy. (Just like the trial power station the Australian Federal government is helping to fund.)

Problem is, as far as I can see, the article says nothing about what happens if a protracted cloudy period covers the power stations. Still, if environmentalists don't go nuts about tens of square kilometres of desert being covered by mirrors, I guess it could help, provided you don't lose much of the benefit in the process of getting the electricity the hundreds of miles to where it is needed.

At least if you use solar power to do the direct electrolysis of water into hydrogen, you have something you can store to generate power later. Someone's looked at that, I assume?

1 comment:

GerryWolff said...

Three points:

* One of the nice things about concentrating solar power (CSP) is that, apart from the collection of solar heat, the rest of the power station is exactly like a conventional power station. This means that it is very easy to provide gas as an alternative source of heat for those relatively rare occasions when there is a long cloudy period. This kind of hybrid system (with facilities to store solar heat) can deliver electricity at all times.

* Less than 1% of the world's hot deserts, if covered with CSP plants, can produce as much electricity as the world currently consumes.

* With HVDC transmission lines, losses are about 3% per 1000 km. This means solar electricity can be transmitted efficiently over *very* long distances.

Further information about concentrating solar power (CSP) may be found at:

http://www.trec-uk.org.uk/index.htm

and

http://www.trecers.net/index.html