Solel och solvärme ur LCC-perspektiv för ett passiv-flerbostadshus

Sammanfattning: This master’s degree project concerns the combination of a multi dwelling passive house with solar energy for the generation of electricity and domestic hot water (DHW). Different alternatives with either solar thermal systems or photovoltaic (PV) systems are compared with two reference alternatives producing DHW from electricity or district heating. The economical comparison uses a life cycle cost (LCC) perspective based on the present value of expenditures for investment, energy and annual operating and maintenance. The energy yields from the solar energy systems were calculated by hand and with simulation software. Calculation and dimensioning of PV systems were carried out with a software called PVSYST. Solar thermal systems were calculated by hand and with the software Winsun Villa Education. Both softwares use hourly weather data for the calculations. The LCCs are lower for the two reference alternatives than for the solar energy alternatives. The reference alternative with district heating generates the lowest LCC. The alternatives with solar thermal energy replace more energy and have significantly lower LCCs than the PV alternatives. The study also shows the importance of using cheap and environmentally friendly backup energy for producing DHW. When aiming for a quantitative energy use target, the DHW-circulation losses ought to be taken into account as these can be extensive.