Researchers Olympus of Germany

The science of solar power is more successful here in Germany than anywhere else.

While the German photovoltaic manufacturers worry about their leading role due to increasing competition from China and the USA, local research into solar power is in the fast track: Innovations develop rapidly, efficiency records fall constantly. Even renowned USA science can no longer keep up.

The fact that the Fraunhofer Institute for Solar Energy Systems (ISE) could break the efficiency record for multiple cells has major significance there, “We were able to set a strong scientific emphasis,” says Frank Dimroth, head solar researcher at the ISE. In January 2009, his team achieved a 41.1 percent efficiency with so-called multiple cells, thus trumping the National Renewable Energy Laboratory (NREL) of the USA, the previous record holder, by 0.3 percentage points.

Multiple cells are classed as the technology of the future: Their manufacture is difficult as they consist of several semi-conductors stacked on top of one another. But in return, they produce twice as much energy as conventional silicon cells. Until now, the technology has been an absolute USA domain: Since the 1970s, the NREL has been researching into “Multi Junctions” in order to provide space stations and satellites with solar energy. In 1980, the USA Department of Energy offered the highest solar research budget in the history of the United States, with 400 million dollars. As a result, the country established itself at the crest of global solar science.

Now German researchers are outstripping their US colleagues, and are also pushing themselves into the leading roles in other photovoltaic areas. With CIS thin-film modules, for example (the abbreviation stands for semiconducting connectors made of copper, indium and gallium as well as selenium or sulphur), the NREL has held the efficiency record for years. In March 2008, it improved the record in a pre-industrial production line to 19.9 percent. However, the Stuttgart-based Zentrum für Sonnenenergie- und Wasserstoff-Forschung (ZSW) (Centre for Solar Energy and Hydrogen Research) is already hot on the heels of the NREL. In the same environment in the spring this year, they achieved 19.6 percent efficiency. “Next, we want to jump the 20-percent hurdle,” announces Michael Powalla, head of the photovoltaic business sector at the ZSW, confidently.