Assessment of PVT-technology efficiency in combined solar power plants

Combined PVT-cycle with gallium-arsenide high-temperature solar cells and solar radiation concentrator is proposed to increase the energy performance of solar power plants. Cooling of the solar cells is carried out by means of the coolant which is the cycle fluid of the steam turbine cycle. Purpose: To determine the quantitative indicators of combined PVT-cycle. Temperatures providing high efficiency must be found. Methodology: The research was conducted based on analysis of the function of the overall efficiency of the combined cycle and analysis of its first and second derivatives. The function of the overall efficiency was constructed using the approximation of experimental research for gallium-arsenide solar cells and analytical relationships for the thermodynamic Rankine cycle. Findings: The values of efficiency of combined PVT-power plants with unijunction and heterostructure solar cells were received. The waste heat was used in classic steam turbine cycle. Originality: The methodology allows us to determine, for the first time, the temperature of the solar radiation receiving system, which provides optimal combined conversion performance indicators. The quantitative values of efficiency of combined PVT-cycles were found. Practical value: The method determining the optimal efficiency indicators can be applied when designing the reception systems of prospective PVT-power plants and other systems with similar thermal conversion cycle.