An Encryption-Based Coordinated Kilowatt and Negawatt Energy Trading Framework

With the increasing penetration of distributed energy resources (DERs), traditional grid-dependent consumers are evolving into active prosumers, who can control their generation and demand while interacting with peer neighbors to earn profits. This paper presents a novel encryption-based coordinated peer-to-peer (P2P) trading framework for kilowatt (kW) and negawatt (nW) transactions, incorporating the utilization of second-life batteries (SLBs) from retired EVs. In this framework, two different types of P2P transactions are coordinated, allowing prosumers to switch their market roles freely between kW and nW markets based on optimization results and market clearing information. The optimal market bidding strategy is determined by the household energy management system (HEMS) optimization, and a double-sided auction method is employed for market clearing. To protect prosumer privacy and prevent potential data integrity attacks (DIAs) in the P2P markets, Rivest-Shamir-Adleman (RSA) digital signatures and Goldreich-Goldwasser-Halevi (GGH) encryption algorithms are implemented. Unlike the traditional battery energy storage systems (BESS) that assume constant charge/discharge power and efficiency, the non-ideal battery models are imbedded to capture the impacts of BESS operation on the real-life P2P trading markets. The battery cycling degradation issue is also incorporated. The effectiveness of the proposed framework is demonstrated on the modified distribution system.