Study on thermoelectric performance of thermochromic coating PV/T system

Abstract

Solar thermal and photovoltaic unit on traditional PV/T system are restrict each other because the collector is installed on the photovoltaic unit. Some coating cover plates were prepared with thermochromic materials of that application in industry, textiles and daily life. The coating cover plate will adjust its optical properties due to the temperature. An innovative thermochromic coating PV/T system was established. The comprehensive experimental device was set up for carrying out test in simulation. Comparing with the fluid beam-splitting PV/T system, there is more difference in the ray transmittance of the thermochromic coating cover plate before periods after discoloration. When temperature is less 45 °C, the heat-collecting effect is better whereas more 45 °C it decreases and then the ray transmittance and the performance of photovoltaic power generation for system are improved. When the mass fraction of 500 nm graphite powder added to the thermochromic coating is 2‰, the heat-collecting effect is the best, and the rate of primary energy utilization of the system is 40.1% in maximum value. The thermochromic coating PV/T system can flexibly adjust the use of photovoltaic power and thermal energy. When the water temperature is lower, the thermochromic coating PV/T system mainly collects heat and generates electricity as a supplement. After reaching the hot water requirement, the system reduces heat-collecting function and improves the photovoltaic power generation capacity, and it is of great practical value. The research results can provide a new solutions method for the application of PV/T systems.