Evaluation of PV/T technology in Sweden

This master thesis was performed for the consulting firm WSP in collaboration with the think tank Besmå. The main aim of the thesis was to examine if photovoltaic/thermal solar systems (PV/T-systems) is suitable for single family houses in Sweden and if it can be a more viable option than photovoltaic systems based on economical and energy performance aspects. The thesis also examines if the owner of a single family house with existing solar panels can benefit from installing an intercooler and a heat-exchanging system that could add the untapped heat of the panels to the house’s heating system. This would decrease the solar panel temperature, thus increasing their efficiency and electricity production. It also examines the possibility of PV/T-systems playing a role in fulfilling the increased energy performance regulations placed upon contractors today, by reducing the primary energy number (primärenergitalet). To achieve these objectives the heat demand of a typical house in Sweden was simulated in VIP Energy based on a real house in Gothenburg which has a photovoltaic system. A modell for electricity production of a solar cell which included the temperature dependency was created in Matlab and a modell of a PV/T-system was created in Simulink. From these models and real data from the existing house and energy system, total production of heat and electricity was acquired. The results showed that the intercooler can enhance the solar cell performance but a life cycle cost analysis found that it was not a neconomically viable option due to its excess cost. It also showed that the PV/T system can be a suitable choice for single family houses in Sweden under certain conditions, mainly depending on uncertain price points. It did enhance the total energy performance of the house in comparison to solar cells but was only economically viable (from a life cycle perspective and not initial cost) when the main heating system consists of an electric heater. Surprisingly, it was also found that smaller PV/T-systems of 5 square meters of module area can yield a better life cycle cost than solar cells, even when the main heating system is a heat pump. Lastly, it was found that a PV/T-system can act as a viable option when building real estate as a method of lowering the primary energy number, assuming a stable and economically competitive price point and that investing in large scale systems leads to a lower price per produced unit of energy and unit of area of modules