Applied Research On Distributed Photovoltaic Solar-thermal Building Integration System

The integrated solar building system can efficiently reduce the energy cost of buildings. Currently, more and more attention is paid on the development and application of the integrated solar building system technology around the world. It is common to have photovoltaic and photo-thermal power systems in buildings in our nation; however, the technology of cooling, heating and hot water supply from solar energy is still under development. To further explore the application of integrated photovoltaic and photo-thermal systems in buildings, and to enhance the performance of the related system, based on the efficient solar energy transformation and utilization technology, the study on performance of thermoelectric conversion in an early-designed CPC-PV/T system is carried out. Anintegrated PV/T building design scheme, which matches the system, is further proposed and analyzed. The study mainly includes the following three parts:1) Starting from the sun, the energy transmission process in the CPC-PV/T system can be categorized as solar energy source process, outer space process, tracking process, light condensation process, frequency division process, and PV/T process. A further CPC-PV/T system model is further built to study the influence of frequency division process. It is indicated that frequency division can lower the temperature rise of the batteries under the same circumstances; however, with low power condensation, the frequency division process will reduce the efficiency, which is expected to be solved by increasing glass optical transmittance.2) The influential factors over transformation efficiency of the CPC-PV/T system are studied inFluent software. The systems under circumstances with different wind speed, temperature, light intensity and water velocity are compared, and the changes of transformation efficiencies are analyzed. It is indicated that system efficiency is little influenced by radiation intensity, but influenced by cooling fluid velocity and circumstances. It needs heat preservation around the PV/T module and its back side.3) Based on early studies, a CPC-BIPV/T system is proposed. Through the introduction and feasibility study of the photovoltaictechnical solution, photo thermal cooling, heating and hot water supplying technical solution and measurement & controlsystem solution, technical support for the industrialization of the combination of CPC-PV/Tsystem and building is provided, which directs the future key researching area.