SIEMENS

Suddenly, he no longer had a quiet moment. There were calls from the Chancellery, ministries, ambassadors, and company representatives by the minute — and although Prof. Hans Müller-Steinhagen from the German Aerospace Center (DLR) in Stuttgart, Germany, is used to acting more like a manager than a researcher, he was still overwhelmed. "When you’ve got 250 people working for you, you can’t just hide in the lab," he says. Still, what he experienced in the summer of 2009, when the whole world started talking about Desertec, was something completely different. In fact, just as Müller-Steinhagen finishes describing this, the phone rings — this time it’s the German Embassy in London, asking if he’d be willing to do a presentation.

Along with the Desertec Foundation and the German Association for the Club of Rome, Müller-Steinhagen’s Institute of Technical Thermodynamics is one of the nerve centers for a project that has been compared in size with the Apollo space program — which culminated in the 1969 moon landing. Desertec, however, focuses on the sun rather than the moon — more specifically on the sun’s energy. In conjunction with the Trans-Mediterranean Renewable Energy Cooperation (TREC), a team of researchers in Stuttgart under the direction of Müller-Steinhagen’s colleague Dr. Franz Trieb has determined that solar-thermal power plants could meet the world’s entire energy requirements. To achieve that, however, it would be necessary to cover an area measuring around 90,000 km² — that’s about the size of Austria — with mirrors.

But, according to the DLR, which has studied the associated technology for over 30 years, if only 15 to 20 % of Europe’s energy demand — the goal of the Desertec project — were covered, an area of around 2,500 km² would be sufficient. An additional 3,600 km² would be needed for the high-voltage power lines that would transmit electricity to Europe.

This vision is now gaining traction because a dozen European companies joined together in July 2009 to form the Desertec Industrial Initiative (DII) and lend additional momentum to the €400 billion project. According to DLR estimates, €350 billion will be needed for the power plants and €50 billion for associated transmission technology.

Partners in the initiative include companies that are normally rivals, as well as a major bank and the Münchener Rück insurance company, one of the largest reinsurers in the world. Siemens is one of the driving forces in the initiative — which should be no surprise given that its portfolio of solutions for solar-thermal power plants includes key components such as steam turbines and receiver tubes, power plant control technology, and systems for transmitting high-voltage direct current with low losses (see articles "China's River of Power", "The Art of Converting Volts").

"Solar-thermal power works — there’s no question about it," says Müller-Steinhagen. In fact, a cluster of power plants in California’s Mojave Desert has demonstrated for over 20 years that a huge amount of electricity can be generated with solar energy. The facilities feed some 350 MW into the grid — enough electricity to power 200,000 households.

There are many reasons why this technology is now being widely discussed in the context of Desertec, with increased awareness of the need for climate-friendly power being chief among them. In addition, technology for low-loss transmission of electricity over long distances has now established itself, while recent innovations have made solar-thermal power plants even more efficient. When oil prices begin rising again, as is expected after the economic crisis, solar-thermal electricity may quickly become competitive. In fact, its production in favorable regions already costs less than €0.20 per kWh.

Major Alliance. If there’s one person who might be called the father of Desertec, it’s Dr. Gerhard Knies. Knies is Chairman of the Supervisory Board of the Desertec Foundation, which developed the Desertec concept that is now being refined in the DII. A retired physicist, Knies’ favorite quote is from Albert Einstein, who said: "We can’t solve problems by using the same kind of thinking we used when we created them." Knies believes this logic fits in very well with the issue of climate change brought about by CO₂ emissions, as this development can only be counteracted by revamping the energy supply system. Over the years, he has put together an impressive group of supporters, including TREC, the Club of Rome, DLR, and Prince Hassan of Jordan.

"We all understood that putting a halt to climate change would require CO₂-free technologies like wind power, geothermal systems and, above all, solar-thermal facilities — all on a mass scale," he says. Whereas Müller-Steinhagen is one of Desertec’s technology designers, Knies got the associated political process moving. His work culminated in the launch of the implementation phase in the summer of 2009, when a consortium was established and support was obtained from companies such as Siemens.

The DII intends to develop business plans and financing concepts for the biggest-ever solar power project within three years. The goal is to build a belt of solar-thermal power plants in North Africa and the Middle East, which would be linked via high-voltage lines with local consumers and European countries. Plans call for achieving a capacity of 100 GW and the supply of 700 TWh per year by 2050, which would cover 15 to 20 % of Europe’s electricity needs.

Obviously, these plants could meet an even higher share of the energy requirement in the dynamically growing countries in which they would be located. The electricity requirement in the MENA Region (Middle East and North Africa) is expected to increase five-fold over the next 30 to 40 years, to 3,500 TWh. "Solar-thermal plants and wind power facilities could, for example, play a key role in the energy-intensive desalination of seawater," says Knies. Moreover, because as much as 80 % of the value created through construction of the power plant facilities will remain in the MENA countries themselves (e.g. through the production of mirrors, foundations, and frames), a project like Desertec would also greatly boost development in the region. According to estimates by Greenpeace, Desertec would lead to the creation of some two million jobs in participating countries by 2050.

Dr. René Umlauft, CEO of Siemens’ Renewable Energy Division, has supported the initiative from the start. "Desertec can make a key contribution when it comes to establishing a sustainable energy supply system," he says. "And with the solutions from its Environmental Portfolio, Siemens is the right technology partner for this visionary project, many of the elements of which have already been implemented in Europe."

For instance, Siemens is the market leader in the construction of new offshore wind turbines, many of which can be found on European seas (see article "High-Altitude Harvest"). Siemens technology can also be found in European solar power plants. At the beginning of 2009, for example, the Andasol parabolic trough plant went online in Andalusia in Spain.

Just Follow the Sun. The Andasol plant is equipped with curved parabolic mirrors laid out in long rows covering an area of 500,000 m². These mirrors will enable the plant, which will consist of three complexes in its final expansion stage, to generate 150 MW in all, and 176 GWh per complex and year. To optimize the facility’s yield, the mirrors continuously track the sun to within one-tenth of a degree of arc. The light they reflect is channeled into vacuum-insulated receiver tubes that contain a special oil that is heated to nearly 400 °C. The oil later transfers its heat to water in heat exchangers, thereby creating steam.

"At that point, a solar-thermal plant begins operating like a conventional facility," says Umlauft. That’s because the downstream "power block," in which electricity is generated from steam, employs the proven technology used in steam-turbine plants.