How peer-to-peer energy trading between households could support an electrified future

Decarbonising Britain’s energy systems will bring big changes to the electricity grid. The proliferation of electric vehicles (EVs), electric heating and embedded renewable generation like solar PV will bring both challenges and opportunities. More electricity will need to be generated and transmitted, and, simultaneously, more households will gain the ability to generate or store their own electricity, becoming active ‘prosumers’ rather than passive consumers.

Research undertaken under Dr Solomon Brown from the Department of Chemical and Biological Engineering considers the potential of community level ‘microgrids’ as part of the renewable energy future. Using computer simulation and optimisation techniques, the group is working to understand how communities of around 100 prosumer households could use their EVs and PV to trade energy peer-to-peer (‘P2P’), bringing both financial and technical benefits.

PhD researcher Tim Hutty explains “At the moment, I can choose to charge my electric car when I know that my neighbour is generating lots of solar energy. This might be a practical thing to do; however, neither of us reap any financial benefit. Instead, the benefits all go to the electricity supplier, who bills me for energy that my neighbour generated. Peer-to-peer energy trading in a community microgrid can provide the incentive for households to cooperate in this sort of way. It may also increase the incentives for households to acquire green technology in the first place.”

A particular focus of the work is ensuring that the different households can coordinate well with each other, particularly regarding the charge and discharge of EV batteries. This is most easily accomplished by placing the EV batteries under centralised control, but such an approach raises obvious questions about how willing people might be to get involved. Alternative approaches use pricing formulas or auction-based methods that enable the households to pursue their own self-interest whilst simultaneously benefitting the overall microgrid.

Results from the work show that P2P trading can make savings for the participants, whilst also incentivising them to behave more altruistically. The P2P scheme can reduce the peak power requirement of the community, as well as the overall amount of imported energy and associated carbon emissions. The research also aims to address the equitability of the system – are the benefits fairly distributed to the different types of household?

P2P trading of electricity is still in its infancy, although interest is mounting, with pilot-scale trials carried out by both Centrica and EDF in recent years. The researchers anticipate that the motivation for P2P will continue to increase along with the prevalence of EVs and solar PV, and hope that their research can provide guidance on the benefits of P2P schemes and how they can be implemented. They also plan to extend their model to include trading of heat as well as power, and to consider hydrogen as a long-term energy storage medium.