The graduation project of Stefan Roest, a student of Sustainable Energy Technology, in TU Delft turned out to be a profitable venture leading to the starting of an offshoot company Eternal Sun.
Solar Collector and Solar Simulator" />Solar collector Stefan Roest TU Delft
Stefan Roest has formulated a new model hybrid solar collector that offers increased efficiency and augmented lifespan than the hybrid type of systems currently available.
The Hybrid solar collectors presently available in the market mix the use of solar cells and a thermal solar collector to perform the functions of power generation and water heating. The left over heat of the electric power generated from solar panels is used to warm up the water. The water in the solar thermal collector moves through a copper piping system positioned over a copper sheet. For the purpose of heating the water, the hybrid solar collectors utilize a transparent cover to draw and retain the heat. Most of the times the materials placed in the solar PV cells when exposed to temperatures of about 120°C gets degraded quickly within 5 to 10 years.
The new hybrid solar collector developed by Stefan Roest replaces the use of a transparent cover, the copper piping and the copper sheet instead the water is run through a large number of aluminum conduits kept directly below the solar panel. The arrangement needed less quantity of heat to warm the water suitably for the use at home. In the new arrangement, Roest opted for thin film solar panels instead of the conventional crystalline silicon PV solar panels to attract the heat quickly. Also, the non-use of cover over the solar panels assisted in maintaining the heat level approximately at 80°. Also the thin film solar panels used in the set up perform better in high level temperatures with an efficiency loss of 10% instead of the normal 20%, thus allowing an extended life span of 15 to 20 years for the system.
The special solar simulator developed by Roest to compute the efficiency of this prototype product also has become a hit. TU Delft has patented the technology and introduced it in the market through its spin-off business, Eternal Sun.