A €400 billion plan to power Europe with Sahara sunlight is gaining momentum, even as critics see high risks in a large corporate project using young technology in north African countries with weak rule of law.
Desertec, as the initiative is called, would be the world's most ambitious solar power project. Fields of mirrors in the desert would gather solar rays to boil water, turning turbines to electrify a new carbon-free network linking Europe, the Middle East and North Africa.
Its supporters, a dozen finance and industrial firms mostly from Germany, say it will keep Europe at the forefront of the fight against climate change and help North African and European economies to grow within greenhouse gas emission limits.
Others warn of numerous pitfalls, including Maghreb politics, Saharan sandstorms and the risk to desert populations if their water is diverted to clean dust off solar mirrors.
They say the concentrated solar power (CSP) technology behind Desertec involves greater costs and risks than the fast-growing patchwork of smaller-scale photovoltaic cell installations that generate most of Europe's solar energy today.
Desertec's founders are lured by the fact that more energy falls on the world's deserts in six hours than the world consumes in a year.
"The Sahara offers every advantage you want - proximity to Europe, virtually no population and more intense sunlight," said George Joffe, a research fellow and Maghreb expert at Cambridge University, who is not affiliated to the plan.
"It would be mad to pass up this opportunity." Proposed by the Club of Rome, an international group of experts that suggests solutions to global problems, Desertec became an industrial project last month when reinsurer Munich Re hosted its launch at its headquarters in the Bavarian capital.
"We have a special relationship with climate change: It affects our core business, the insurance of weather-related natural catastrophes, which count among the most expensive losses we have to bear," said Peter Hoeppe, head of Munich Re's Geo Risk Research department.
Many European governments aim to cut their greenhouse gas emissions by 80 per cent below 1990 levels by 2050.
Desertec's backers say it would also be a positive gesture from the developed world to countries of the Middle East and North Africa, which stand to suffer most from the more frequent droughts and desertification blamed on global warming.
They have yet to draw up a business plan or specify how it will be funded but hope to recruit shareholders and partner companies from a variety of countries.
Desertec officials say the Sahara could one day deliver 15 per cent of Europe's electricity, but expect the plan to advance in small stages with completion not before 2050.
Supporters of more established solar energy technology, such as photovoltaic cells, argue decentralised generation will prove more popular as falling prices make the heavy infrastructure needed for CSP unviable.
They also think European governments, which already accept the risk of importing energy from north African countries such as Algeria, would given the choice opt for the security of producing renewable energy within their own borders.
"Sahara power for northern Europe is a mirage," said Hermann Scheer, a member of Germany's parliament and head of the European Association for Renewable Energy.
"Those behind the project know themselves that nothing will ever come out of this," said Mr Scheer, an architect of renewable energy policy in Germany, which included a strong emphasis on photovoltaic technology.
Mr Scheer said the costs of Desertec were being downplayed artificially and its technical capabilities over-estimated.