Alternative energy: The solar sandwich

With a new technology win photovoltaic manufacturers twice as much electricity from sunlight as before. Corporations promise of solar energy for the future, which is as cheap as electricity from coal power plants. This is made possible a record yield with a simple trick.

A strong magnifying glass and a sheet of newspaper – all it takes to light a campfire. At least as long as the sun shines strong: She has so much energy that the paper bursts into flames when the concentrated solar rays hit it.

Use this as simple and effective principle to the photovoltaics industry. Companies and research institutes working on innovative solar modules, which are equipped with special lenses. As a magnifying glass to concentrate the rays of the sun around the 500- to 1000-fold – and hence their energy content. The solar cells can thus gain very small area much electricity.

The CPV technology (Concentrated Photovoltaics) scientists achieve in the laboratory is already efficiencies of 40 percent and more. For factory-made CPV modules figure is still 30 per cent. An enormously high value – the commercial silicon modules are just half.

And while manufacturers of conventional modules tedious to every tenth of a percent more efficient fight the concentrator specialist screw the efficiency of their products in the shortest time equal to whole percentage points upwards. The end of the story is far from being achieved: “I assume that we are at the cellular level to break the fifty percent mark in the next few years,” says Andreas Bett from the Fraunhofer Institute for Solar Energy Systems, the large proportion of the has development of this technology. Bed is the end of October awarded the German Environmental Award, he is one of three winners this year.