This paper presents an automated peer-to-peer negotiation
strategy for settling energy contracts among prosumers in a Residential
Energy Cooperative considering heterogeneity prosumer preferences. The
heterogeneity arises from prosumers' evaluation of energy contracts
through multiple societal and environmental criteria and the prosumers'
private preferences over those criteria. The prosumers engage in
bilateral negotiations with peers to mutually agree on periodical energy
contracts/loans consisting of the energy volume to be exchanged at that
period and the return time of the exchanged energy. The negotiating
prosumers navigate through a common negotiation domain consisting of
potential energy contracts and evaluate those contracts from their
valuations on the entailed criteria against a utility function that is
robust against generation and demand uncertainty. From the repeated
interactions, a prosumer gradually learns about the compatibility of its
peers in reaching energy contracts that are closer to Nash solutions.
Empirical evaluation on real demand, generation and storage profiles –
in multiple system scales – illustrates that the proposed negotiation
based strategy can increase the system efficiency (measured by
utilitarian social welfare) and fairness (measured by Nash social
welfare) over a baseline strategy and an individual flexibility control
strategy representing the status quo strategy. We thus elicit system
benefits from peer-to-peer flexibility exchange already without any
central coordination and market operator, providing a simple yet
flexible and effective paradigm that complements existing markets