Technical and economic analyses of grid-connected residential PV considering batteries and peer-to-peer energy sharing

The widespread installation of solar photovoltaic (PV) promotes using batteries and peer-to-peer (P2P) energy sharing, where prosumers sell excess PV energy to their peers. Therefore, this paper develops four mathematical energy trading models using transient system simulation for grid-connected residential PV, considering batteries and P2P energy sharing: Peer-to-grid (P2G); P2G with batteries; P2P; and P2P with batteries. These four models are proposed in order to evaluate the impacts of batteries and P2P energy sharing on reducing grid energy consumption and increasing PV energy utilisation by prosumers. An Australian house with 10 kW PV in Geelong, Victoria, is used as a prosumer, and we have collected hourly data on the solar PV generation and electrical load of the house over a year. Three consumers are assumed to be in the analyses, and their electrical loads are developed based on the prosumer's load profile. Results indicate that while batteries and P2P energy sharing can effectively increase PV energy utilisation and reduce grid energy imports for the prosumer, batteries hinder the level at which the consumers can decrease their grid energy consumption because of the operational strategy of charging batteries before P2P energy sharing. The economic analysis demonstrates that P2P energy sharing creates a positive net present value (NPV) for the prosumer over 20 years under the current economic conditions, and the highest cumulated NPV reaches AUD 4,929 at the battery capacity of 10 kWh. The minimum payback period that the prosumer can attain with PV-batteries is 12 years, at which point the battery has a capacity of 7.5 kWh. Also, the sensitivity analysis verifies that the payback periods of PV and batteries become more desirable when some influencing factors, such as initial equipment purchase costs, P2P energy sharing prices, and annual discount rates, become more favourable to users.