Via EUREC member ITER
One of the main demands of the photovoltaic sector is the availability of solar panels able to be integrated in architectural projects. In that sense, replacement of conventional materials composing a standard solar panel for innovative elements represents advancement for this technology. To this end, AiSoVol project (photovoltaic generation solution as an alternative construction material) aimed to develop a new concept of photovoltaic solar module, easily integrated and versatile, conceived for building integrated photovoltaic applications.
Thus, diverse modules have been fabricated
by encapsulating its constituent electrical elements with sandwich lamination techniques and using a transparent polycarbonate as frontsheet instead of tempered glass. As backsheet, besides conventional layers, it has been used transparent polycarbonate too. A reinforcement grid, such as the ones used in sail technologies, has been integrated within the sandwich so as to strengthen the module and avoid the need for aluminium frames. This type of solution will provide not only lightness and flexibility but virtually geometry free photovoltaic modules which can adapt to any kind of shape. The conventional manufacturing process has been maintained with a view to adapt the equipment and systems of the ITER’s factory, although it should be also adjusted to the new materials. Thus, lamination process parameters (time and temperature) have been also analysed in order to figure out the most suitable lamination conditions.The modules fabrication process was studied in two different stages. First, a visual inspection was carried out in order to evaluate the appearance of the laminates and the buckling degree while adjusting the lamination parameters. Thus, a stepwise heating lamination process, which progressively melts the encapsulant in four steps at constant temperature, was developed and validated. Defects such as bubbles and lack of adhesion within the laminates were avoided and the buckling degree was minimized. Efforts were made to introduce the reinforcement grid but results achieved demonstrated a lack of adhesion around this layer. Second stage of the research was focused on the characterization of the modules using electrical tests and electroluminescence imaging. In the end, two different types of modules with satisfactory results were manufactured. The first type was manufactured using polycarbonate as frontsheet and backsheet, and is intended to be integrated into the building structure as an active window and provide both light and energy. Second type consisted on a module of polycarbonate as frontsheet and a conventional opaque backsheet. This one would be able to be screwed onto a building panel.
AiSoVol project has been funded by the National Programme for Research Aimed at the Challenges of Society (Spain). The total budget was 1,008,543.07 €, of which 849,495.70 € have been financed by European Regional Development Fund (ERDF). The project, which began on 1st October 2015 and ended on 30th September 2018, is a partnership between of the Technological and Renewable Energy Institute, S.A. (ITER) as coordinator and the National Renewable Energy Centre (CENER) as partner.