  Deploying distributed renewable energy at the demand side is an important
measure to implement a sustainable society. However, the massive small solar
and wind generation units are beyond the control of a central operator. To
encourage users to participate in energy management and reduce the dependence
on dispatchable resources, a peer-to-peer energy sharing scheme is proposed
which releases the flexibility at the demand side. Every user makes decision
individually considering only local constraints; the microgrid operator
announces the sharing prices subjective to the coupling constraints without
knowing users' local constraints. This can help protect privacy. We prove that
the proposed mechanism can achieve the same disutility and flexibility as
centralized dispatch, and develop an effective modified best response based
algorithm for reaching the market equilibrium. The concept of absorbable region
is presented to measure the operating flexibility under the proposed energy
sharing mechanism. A linear programming based polyhedral projection algorithm
is developed to compute that region. Case studies validate the theoretical
results and show that the proposed method is scalable.
