Sunday 26 July 2009

Desert sun power pulls in the big guns

Mark Jansen
It's a simple idea: cure Europe’s addiction to fossil fuels by connecting its electricity-hungry consumers to the deserts of north Africa that are rich in solar energy.
Simple, but surely this is straight out of science fiction? There may be plenty of sun power in the Sahara, but the cost and political problems in creating an infrastructure to harvest it are daunting.
Some serious players, however, have joined together to see if the obstacles can be overcome. Munich Re, the world’s largest reinsurance group and a leader among financial institutions on climate change, brought together 12 finance and energy companies in Munich a fortnight ago to seek a solution.
The reinsurer, which has had to make high payouts in recent years for damage caused by erratic weather, believes solar power in north Africa could deliver 15% of Europe’s electricity by 2050.
The concept of harnessing solar power from the deserts has long been promoted by Desertec, a European network of scientists and engineers, but this is the first time that commercial companies have come together to discuss how to turn it into reality.
Deutsche Bank, Eon, Siemens and ABB attended the meeting, along with representatives from Desertec, the European Union and the League of Arab States.
Delegates agreed to fund a three-year feasibility study and set up a consortium, with all 12 members having pledged to contribute to the $2.5m (£1.5m) running costs for the first year.
So what is the likely price tag for a scheme that would provide the 15% specified by Munich Re? $560 billion.
“We believe that the technology is available but we want to see if the concept can be realised from a political and economic point of view,” said the reinsurer.
The plan would depend on an enormous expansion of concentrated solar power (CSP) plants in countries such as Algeria, Tunisia and Morocco. CSP plants use mirrors to direct sunlight into a small area and generate heat. That creates steam, which drives a turbine to generate electricity (see graphic above).
The advantage over photo-voltaic solar panels is that it does not need expensive silicon to generate power. CSP needs lots of direct sunlight, making it unsuitable for European countries but ideal for deserts.
Power generation can continue at night, using spare heat that has been held over from the daytime and stored in tanks filled with melted salts such as sodium nitrate or potassium nitrate, or in blocks of concrete. This enables generators to offer a constant power supply and match the peak demand that occurs in the evenings.
Desertec claims that the world’s present electricity needs could be met by covering just 1% of the world’s deserts with CSP. Cost is a problem. Electricity generated by CSP costs about €0.15 per kilowatt, compared with €0.06 per kilowatt for electricity generated from coal or nuclear stations.
Supporters of the Desertec plan believe the price of CSP can be brought down to the same level as fossil fuels if European governments provide subsidies for 10 to 15 years.
These would probably take the form of feed-in tariffs, which would give CSP generators a guaranteed price above market rates for a fixed time.
These subsidies would cost anything between €50 billion (£43 billion) and €250 billion, according to a study by the Vienna-based International Institute for Applied Systems Analysis, which presented its findings at the Copenhagen global warming conference in March.
At least another €200 billion would be needed to build the CSP plants and invest in a transmission grid that could bring the power to European countries.
The institute’s Anthony Patt believes that north African countries are cautiously supportive of the Desertec concept, provided local energy needs are also met. “I’m confident that a deal can be struck that is good for north Africa,” he said.
Munich Re insists the money can be found: “We believe the Desertec concept can be financed by the capital markets if the right companies are involved and there is a regulatory framework that offers good investment opportunities,” it said.
The project would also provide an economic boost to the Sahara region, with Desertec estimating that about 2m jobs would be created by 2050.
Spain so far leads the world in CSP, with six plants already operating and at least 12 more under construction. It offers feed-in tariffs that are guaranteed for 25 years, which has encouraged investment.
Two CSP plants have been operating in California since 1990. Small CSP plants are also being built in Algeria and Morocco.
Despite the size of the challenges, Gerry Wolff, co-ordinator of Desertec in Britain, said he was increasingly optimistic the scheme would succeed. “People are beginning to throw their weight behind this. The logic of the idea is almost inescapable and I’m sure it will happen,” he said.
The plan is not without its critics. Hermann Scheer, head of the European Association for Renewable Energy (Eurosolar), has said the initiative is unviable, claiming its proponents have underestimated the technical and political challenges and the likely cost.
“We could invest the €400 billion here,” said Scheer. “Nothing will ever come of it.”