Some people compare it with the construction of the Panama Canal. Others see it as the greatest technological challenge since NASA’s Apollo programme which, after all, put the first man on the moon. Whatever the case, the news that circled the world from Munich on 13 July leaves no one exactly cold: on that Monday twelve companies called Desertec into being, probably one of the most ambitious technological projects in history. Huge solar thermal power plants will capture the desert sun in North Africa and Asia to produce electricity which is partly destined for Europe: this is Desertec’s vision. The idea is that 15 per cent of Europe’s energy requirements can be covered by the year 2050 in this eco-friendly way. 85 per cent of the energy produced by Desertec is however designated for use by the participating states of North Africa and Asia. The project will cost an estimated 400 billion euros.
The Memorandum of Understanding has been signed by Munich Re, Siemens, RWE, E.ON, HSH Nordbank, Deutsche Bank, ABB of Switzerland, the solar energy specialists and plant constructors MAN Solar Millennium, Abengoa Solar of Spain, Schott Solar, Cevital of Algeria and M+V Zander. “We are pursuing a visionary plan,” said Torsten Jeworrek, member of Munich Re’s Board of Management. The world’s largest reinsurance company is one of Desertec’s key initiators. “If it is successful, we will make a major contribution to combating climate change. The ecological and economic potential is huge. We will do our utmost to make this vision reality.”
It was announced in Munich that the Desertec Industrial Initiative (DII) planning entity will be founded in October 2009 to start turning the gigantic project into reality. The first results are expected in three years at the latest. These recommendations will determine where and how the solar energy will be gained from the desert. Whatever the decision, the climatic conditions in the proposed regions are excellent. Six hours of sunlight in the deserts provide more energy than the whole world consumes in a single year.
The technology for solar thermal energy plants is also unproblematic. Desertec plans to install parabolic trough concentrators (PTCs), a technology already used in the USA and in Spain, which in some cases has been supplying energy for decades. Unlike solar cells, PTCs do not transform sunlight directly into electricity but reflect it by means of mirrors onto a receiver. The system has “absorber tubes” containing a special heat transfer fluid which the concentrated solar energy heats to a temperature of around 400 °C. The heated fluid then flows to a heat exchanger where steam is produced. The super-heated steam drives a turbine generator which in turn produces electricity. The principle is basically similar to that used in conventional coal-fired power plants. Parabolic trough concentrators also have a great advantage over photovoltaic power plants: they supply electricity during the night when there is no sun, because an integrated storage tank continues providing the heat needed for the turbines.
At the moment the initiators still face three unsolved issues: the overall financing of Desertec, the location of the plants and the course of the power supplies all have to be clarified. But the twelve companies are certain about one thing: there’s no going back. “Progressive climate change can become the greatest risk to humanity,” says Nikolaus von Bomhard, Chairman of the Munich Re Board of Management.
