Matching characteristics and AC performance of the photovoltaic-driven air conditioning system

Photovoltaic-driven Air Conditioning systems (PVAC) use local electricity generated by distributed Photovoltaic (PV) to drive Air Conditioners (AC). Both the AC cooling load and the PV electricity generation are affected by solar radiation. The PV generation cannot dynamically supply the AC power consumption during the operation. In this study, the matching characteristics of a PVAC were investigated using a case in a 207.34 m2 office room. A coupled simulation model was built, which integrated with a building model, a PV calculation model, an AC model, and a control strategy. More specifically, the AC was modeled with two heat exchangers, a compressor, and a throttling device. Both the building and the PV were simulated in EnergyPlus. The AC compressor speed was controlled so the AC power consumption could match the PV generation when the indoor temperature was within the temperature control zone. The daily matching characteristics of PVAC were strongly affected by the PV capacity. The results showed that the PV factor (PVF) should be set to 1 in order to match the AC and PV power and maximize the AC efficiency. A battery factor of at least 0.7 could ensure the grid flexibility. Finally, the optimized design of PV, battery, and AC capacities was suggested.