A peer-to-peer exchange framework for microgrids to improve economic and resilient operation

Abstract

Peer-to-peer (P2P) exchange is an emerging approach in smart grids which enables users to share their energy production or storage surplus or the flexibility of their demand with other end-users. This provides benefits to both energy producers and consumers. In this work, a P2P exchange framework methodology is developed. It relies on a Time-of-Use (ToU) tariff scheme to value the benefit in time-shifting demand to low cost / low carbon periods. Two groups of stakeholders are considered, the local distribution network operator (DNO) and the microgrid (MG) users. Energy trading follows three principles: First, energy sharing occurs by using the storage and renewable assets of the microgrid. Second, P2P exchange is enabled during the high-tariff period and third, it is based on cooperation to achieve mutual benefits for the DNO and the MG users. The stakeholders share the cost and benefits of P2P energy trading. The main steps of the developed methodology include a battery sizing process, user categorization and priority order, zoning and optimum battery discharging. The electrical limits of transformer and storage inverter power are considered in the process. The developed methodology investigates the benefits gained by the DNO and MG users. Benefits are examined in terms of economic benefits for the stakeholders (profits), system resilience in case of faults, carbon emissions reduction and energy storage lifetime increase. Case studies are used to illustrate the capabilities of the methodology in determining the expected performance of a P2P scheme under a range of conditions and geographical locations. The results show that this method of P2P exchange will have significantly different impacts depending upon the local conditions for demand, generation, resilience standards and tariff structure.