Using solar heat in a wide variety of ways

In human terms and dimensions, solar energy is inexhaustible, and yet its technical application is not yet fully matured. “We need intelligent solutions so that we can generate power around the clock and can also store the energy efficiently,” says Professor Robert Pitz-Paal, Head of Department Solar Research at the Institute of Technical Thermodynamics, German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt – DLR). DLR experts are working flat out on these solutions in several EU projects. They have helped to build the largest European test facility on a 100 or so hectare site on the Plataforma Solar in Almería in South-Eastern Spain which the Spanish partner organisation CIEMAT is meanwhile running. They are testing new components here to either convert sunlight into electricity or to store the solar energy, for example, in the form of hydrogen. To this end, DLR experts and their European partners have jointly developed the hydrogen reactor called Hydrosol that continuously and extremely efficiently uses the Sun’s heat to split water into hydrogen and oxygen.

A solar-hybrid gas turbine has meanwhile become operational. DLR researchers developed the test facility in cooperation with eleven international partners working under the EU project Solhyco and have now installed it on the solar tower CESA-1. An array of mirrors directs the sunlight onto three solar receivers that gradually heat the compressor air of the 250 kilowatt gas turbine up to 800° Celsius. Only when needed does the turbine‘s biodiesel driven combustion chamber step in so that electrical energy can be generated regardless of time of weather. “These tasks were very demanding,” says Pitz-Paal, “but our scientists eventually solved them.”