Energy efficiency of solar collector with translucent photovoltaic cells

Solar energy is a renewable source with the greatest potential for sustainable energy production. Among modern energy societies, the use of heat and electricity predominates. Both energy carriers can be produced with relatively high efficiency with solar energy utilization. However, the conversion efficiency is higher if heat and electricity is produced simultaneously. In the master's thesis, the research and technological trends in the field of combined solar heat and electricity generators (PV/T) is presented and the design of a solar PV/T generator is built on the basis of a commercial vacuum two-pipe solar collector was proposed. An algorithm for the calculation of solar radiation on the circular surface of the receiver was developed and a combined model of heat transfer and electricity production was built for determining the efficiency of solar energy utilization for heat and electricity. The model enables the determination of energy flows for PV/T generators with opaque and translucent solar cells. The model was validated with in-situ measurements of the stagnation temperature of the absorber. A validated model was then used to optimize the PV/T design with respect to the size of the photovoltaic module and its transmittance. Energy production was analyzed for different climatic conditions. Is found out that the optimum size angle of PV cells is 90° since increasing the size angle to 180°only provides 30% more electricity. In both cases PV cell does not affect significantly to heat production as it is reduced by approximately 5%