ABSTRACT
Although the idea of producing a solar collector for both electricity and hot water is not new, this new generation is based on a very innovative concept. In a feasibility study [1] we have collected a lot of information about important aspects (costs, technology, market, contacts with industries, ...) to prove that further development is worth being done. The results are encouraging since they show: A potential market does exist for several specific applications (about 10 MW in 2005) Photovoltaic (PV) thin film technology is likely to be suited for this application from a technical and financial point of view, provided that the long term stability of the cells at temperatures above 100°C are confirmed Several photovoltaic industries are ready to collaborate in this development at different levels of participation The several technical concepts proposed are suited for the proposed application. The feasibility study showed that the competitiveness of a hybrid collector depends on several technical requirements of the integrated PV-module. The most prominent aspects are high solar absorption and compatibility with high temperatures. The goal of the present study is to verify if these technical conditions are met for the available amorphous silicon (a-Si) technology. Measurements on commercial unencapsulated samples from 6 different manufacturers based on different substrates (glass, stainless steel, polyimide) were performed. Absorption values are comprised between 78% and 90%. Some samples heated up to 210°C for one hour kept their original properties while the others showed modified characteristics.
