Thursday, February 21, 2008
Think back. Like before the Ipod, the Iphone, Google, the Breville toaster, even before black and white television, to the 1880s. Back then two men had a fight over the future of electricity and how it would reach us.
In one corner was Thomas Edison. He backed DC (electrons flowing in one direction around a circuit). In the other corner was George Westinghouse who backed AC (in which the electrons shuffle back and forth). Edison lost. The reason he lost was because over short distances spanned by early power grids AC suffered lower losses than DC. Subsequently, it became industry standard.
So what’s the big deal? Well, these days electricity travels much further than it didâ€¨in the 1880s. And DC suffers lower losses than AC. So not only does that make DC better in its own right but it would allow electricity grids to be restructured in ways that would make wind power more attractive. That would reduce the need to build more conventional (and polluting) power stations.
You see, wind power has two problems. You don’t always get wind where you want it. And secondly, you don’t always get wind when you want it.
According to Jürgen Schmid, head of ISET, an alternative-energy institute at the University of Kassel, Germany, the answer to both these problems is a continental-wide power distribution. Then the question of where the wind is blowing would no longer matter as the wind is almost always blowing somewhere. If it were windy in Spain but not in West Wales, current would flow in one direction. Conversely if it were a blustery day over here, then it would flow in the other direction.
The ‘when’ aspect of the equation would be to use a country within the European grid to store the electricity until you need it. So how does that work? Well, for example you could use Norway’s hydroelectric plants. The power is used to pump water up into the reservoirs that feed the hydroelectric turbines. That way the power is on tap when you need it.
Should the wind drop all over Europe, which happens rarely, the hydro plants could fill the gap for up to four weeks. Complicated, but at the same time, simple too.
The reason it has not been built goes back to that fight between Edison and Westinghouse back in the 1880’s. He won because high voltage is the best way to transmit power. The higher the voltage, the smaller the loss. Yet AC with its shifting current runs to earth easier, which is another way of saying it loses its power. Hence the reason why the pylons are so high off the ground.
In short, a DC pylon will beat an AC one over long distance (600 miles). And a DC line will beat an AC line at a distance as short as 20 miles. That’s why Dr Schmid calculates that a DC continental grid would allow wind to supply at least 30% of the power needed in Europe. And do so reliably.
Edison was right. DC was the best way to transmit electricity of any given voltage. He was ahead of his time.
1 AC may no longer be the future.
2 DC suffers lower losses over longer distance.
3 This will make wind power more commercial.
4 A European-wide power distribution would mean that it won’t matter where the wind is blowing as it is almost always blowing somewhere.
5 Norway has started building DC power lines between Scandinavia, the Netherlands and Germany.
6 Edison may have been right after all.
TREC say the same - use HVDC to transmit clean electricity from concentrating solar power as well as wind throughout Europe, Middle East and North Africa:
Thanks to Howies for telling the story of electricity so well - they make cool clothes too.
Friday, February 08, 2008
The very fact that within just a matter of a few months a second renewable energy conference devoted entirely to CSP was held in Spain is no co-incidence. This is an industry that is evolving by the day and such is the promise of it being on the verge of a tipping point was demonstrated by who attended. This time, attendees did not merely include international as well as national industry players but also investors and the speculators. VC's (who happily just want to throw money at CSP but complain that there aren't enough projects for them to invest in) and banks (who are becoming remarkably CSP friendly in their support) vied for space with oil and power companies who are now considering extending their rapidly depleting energy portfolios into CSP. Suddenly everyone is recognising the potential opportunity. Sign of the times.
Dr Gerhardt Knies, who has shaped the bold vision of the EUMENA - DESERTEC alliance over the past few years, now presents a viable roadmap for rapid CSP commercialisation, comparable to the remarkable achievement of the Apollo mission. To reach the goal of 3,200TWh/y required by 2050 would demand rapid deployment on the scale of 1GW every day from 2020. He calls for a EUMENA solar energy alliance - an alliance between Europe, the Middle East and North Africa to build an HVDC supergrid and share the solar resources. This is now beginning to capture the imagination of politicians and commissioners alike.
Building on the phenomenal success of feed-in tariffs for CSP in southern Europe, an EU commissioned Solar Initiative is due to commence next month. The groundswell of support for a EUMENA solar co-operation at all levels demonstrates that what was once CSP power-point is now becoming CSP power plant.
Such is the success of CSP in Spain, that the feed-in tariff cap has already been reached 3 years early. The industry is waiting to hear how far the cap will be extended to ensure progress of further development projects in the pipeline. Meanwhile in the USA, the future acceleration of CSP remains dependent on the extension of the Investment Tax Credit to ensure crucial investor support continues. They too expect to hear very soon whether a further extension of 8 years has been granted.
It is no longer a matter of 'if' but now a matter of 'when'. One thing is for sure, the next few months for CSP are full of promise.
The Pros and Cons of Solar Power
Even Malcom Wicks MP finds the prospect of CSP rather exciting. To hear the latest on CSP: Costing the Earth podcast: Bring Me Sunshine