Enhance the Effectiveness of Peer-to-Peer Trading in Renewable Energy Community by Innovative Imbalance Price Settlement

This paper proposes a system, CosyGrid, to achieve the objective of Renewable Energy Communities (RECs), such as maximizing self-consumption, through Peer-to-Peer (P2P) trading. In P2P trading, each order from the peer is matched with an order (or orders) from any other peer (peers) in the same REC marketplace. But it is often not possible to fill all orders of peers with matching orders from the other peers. Those orders from the peers that remain unfilled at the start of the delivery period but cannot be cancelled (i.e. are not flexible) are matched with the peer's retailer as per the supply agreement, based on actual volumes imported or exported. In this proposed design for CosyGrid, contracts are instead settled based on contracted volumes of consumption and production and the difference (imbalance) between actual and contracted volumes, and the retailer contracts for unfilled orders are settled at a higher spread between buy and sell price than the supply agreement. These adapted supply agreements allow for stronger p2p price signals and are referred to in CosyGrid as Framework agreements. But the resulting difference between supply and Framework agreements can negatively impact the effectiveness of P2P trades to achieve the REC's objective. To minimize the impact, CosyGrid settles imbalances such as to ensure that the aggregated value in Framework agreements is the same as the aggregated value in Supply agreements. A price per unit of imbalance called the Imbalance price, is calculated, and applied to every end-user proportional to the individual imbalance. The proposed approach will incentivize end-users to respond to price changes and motivate them to use accurate forecasts for their orders, which will further improve the effectiveness of P2P trading.