Roasting built a prototype and built an actual Solar Simulator, that he to test the efficiency of its prototypes. It turned out to be great commercial interest in this Solar System Simulator. This motivated Roest and a partner, the University launch Delft spin off company eternal Sun, so they could that brought solar system Simulator on the market. Eternal Sun recently came at the European finals of the BE.Project, a competition for student entrepreneurs.

Solar Collector

A hybrid solar collector is a combination of a photovoltaic solar panel and a thermal solar panel. The residual heat from the PV solar panel used to heat water. The water flows through a pipe system on a copper sheet. One very much heat is required to heat the water in the pipes. That is why the solar collector with a transparent cover is, to hold back the heat helps equipped. Unfortunately the material in the PV affected solar cell uses fast under temperatures of about 120 degrees. As a result, the efficiency is reduced by about 20 percent, and it has a lifespan of between five and ten years.

For his graduation film research as part of a master's degree in sustainable energy technology, developed Stefan roasted a new kind of hybrid solar collector with high electrical efficiency and a longer life. For starters, is roasting the solar collector does not require a transparent cover. The water flows through a variety of small ways aluminium directly under the solar panel instead of copper pipe and a copper sheet. Therefore, less heat is required to sufficiently heat the water for domestic use. Roasting chose not even to a crystalline silicon PV solar panel using the decision for a thin-film solar modules, place. It is easier to move heat from this type of solar cells. Getting rid of coverage means that the heat of the solar panel to 80 degrees are limited.

Another advantage of thin-film solar modules is, that these relatively well at high temperatures. At a temperature of 80 degrees, a loss of efficiency occurs approximately 10 percent instead of the 20 per cent in the case of crystalline silicon solar cells. Roasting hybrid collector has an estimated lifespan of 15 to 20 years.

Roasting the new solar system under the supervision of Professor of the photovoltaic developed materials and devices, Miro Zeman, who says: "." "This innovative design could play an important role in the development of affordable and efficient hybrid systems for the home"

Solar Simulator

Roasting developed a special Solar Simulator measure the efficiency of its prototypes. Almost immediately, it was commercial interest in this Simulator and the appropriate technology was fast from the Delft University of technology patented. Roasting and his partner Chokri Mousaoui since the Simulator on the market brought about their TU Delft spin-off companies eternal so eternal Sun recently came out on top in the European final of the BE.Project competition for students from universities with an innovative business model, which was organized by the technology consulting firm BearingPoint. The eternal Sun-team now on six students and graduates include, and five Solar Simulators have been sold since January.