Peer-to-peer electricity trading as an enabler of increased PV and EV ownership

Peer-to-peer (P2P) energy trading enables households to trade electricity with one another, rather than just with their supplier. This can help to incentivise the shifting of electrical loads to align with local renewable generation, which leads to decreased dependence on grid electricity and can bring financial savings for households. P2P is expected to be particularly suitable to complement embedded PV generation and electrical vehicles (EVs), two key technologies for grid decarbonisation. In this work we simulate P2P energy sharing for a local microgrid of 50 households with PV and EV ownership at various penetrations. In particular, we consider the merits of P2P in combination with uni-directional EV chargers (‘V1G), and with chargers that can discharge EV battery energy to the home (‘V2H’) or the grid (‘V2G’); we also consider the use of community energy storage (‘CES’) as an alternative to storage of energy in EV batteries. We simulate the interactions of the households with the P2P energy market over one week, for each of three seasons, and evaluate the microgrid’s energy independence and the financial savings for households. Results suggest that P2P trading with V1G can effect an increase in shared energy, modest improvements to microgrid self-sufficiency, and improvements to household bills. However, the combination of P2P with V2H brings advantages substantially greater than either innovation individually. The typical household can save approaching £100/a (compared to an average bill of ca. £540 with no P2P), with savings exceeding £200/a in some situations. Importantly, we find that the P2P can achieve savings regardless of technology penetration, and furthermore, all types of household can benefit, including households that own both PV and EV. Under the market mechanism considered, we find only negligible impact for allowing V2G in addition to V2H.