Solar power from the deserts

In just six hours, the world’s deserts receive more energy from the sun than humankind uses in one whole year. The Desertec Industrial Initiative, which was founded in October 2009 by a number of major industrial companies, aims to provide 15 per cent of the European electricity demand by 2050 through imports from solar thermal power plants in North Africa and the Middle East. The Desertec concept builds on research projects and detailed studies carried out by German Aerospace Center.

“From 2025 onwards, this electricity will be less expensive than mid-load electricity from fossil fuel fired power plants,” says Professor Dr. Hans Müller-Steinhagen from the Institute of Technical Thermodynamics at the DLR, where this work has been done. Because the technology works. Solar thermal power plants have been working reliably in the United States for more than 20 years, and DLR engineers have substantially improved the performance of many key components and operational procedures since then. In early 2009, the world’s largest solar power plant (Andasol 1) went online in Andalusia, followed by an identical power plant Andasol 2 later in the same year.

Andasol 3 is already under construction. DLR experts have made significant contributions to the success of these plants. Andasol 1 produces 50 megawatts of power. And what’s more, for up to 20 hours per day in summer. 520,000 square metres of parabolic trough collectors catch the solar heat at temperatures up to 400°C, and two giant tanks filled with liquid salt store the excess energy not required for electricity generation during the midday hours. The stored energy enables the plant to continue delivering the full power for up to eight hours after sunset.

After years of hard work and slow progress, this technology is now entering the markets worldwide at a rapid rate. Major international companies, including Siemens, RWE, Deutsche Bank and Münchner Rück in Germany, have joined forces to kick-start the Desertec concept, which may involve an investment of 400 billion euros up until 2050 for construction of solar thermal power plants in North Africa and high voltage direct current lines from Africa to Europe. Most of this investment will be recovered from the sales of the provided electricity. This means that the concept developed by the DLR scientists, which not only secures energy supply but also reduces greenhouse gas emissions and provides the conditions for sustainable growth of the MENA countries, may be implemented quickly.