Optimized design of a distributed photovoltaic system in a building with phase change materials

Building decarbonization is one of the most important ways to stop or reverse climate change. Phase change materials (PCMs) were embedded into a building wall to reduce air conditioning energy consumption and related carbon emissions in this article. Moreover, a distributed photovoltaic (PV) system was designed to provide electricity for the building. The thermal and electrical performance of the building with four different amounts of PCMs and a PV system was simulated and compared with a building using PV system only. To validate the simulated results, an experimental apparatus for buildings with PCMs and a PV system was designed and constructed. Results show that the peak demand load is reduced by maximum of 47% using 5.2 vol% PCMs and shifted by one hour in summer. However, the demand load is 1.3% higher during daytime in winter. Three different optimizations were conducted with the aim of highest building self-balance and PV self-consumption as well as minimum interactions between buildings and grid. The economic benefits for the building with PCMs are higher because of the reduction of peak demand load. However, the payback period is 0.5 year longer for the building with PCMs than the reference building. The carbon emissions are reduced by 11.58 kg more using 5.2 vol% PCMs in a building with an area of 6.25 m2, compared to the reference building.