  With the advent of prosumers, the traditional centralized operation may
become impracticable due to computational burden, privacy concerns, and
conflicting interests. In this paper, an energy sharing mechanism is proposed
to accommodate prosumers' strategic decision-making on their self-production
and demand in the presence of capacity constraints. Under this setting,
prosumers play a generalized Nash game. We prove main properties of the game:
an equilibrium exists and is partially unique; no prosumer is worse off by
energy sharing and the price-of-anarchy is 1-O(1/I) where I is the number of
prosumers. In particular, the PoA tends to 1 with a growing number of
prosumers, meaning that the resulting total cost under the proposed energy
sharing approaches social optimum. We prove that the corresponding prosumers'
strategies converge to the social optimal solution as well. Finally we propose
a bidding process and prove that it converges to the energy sharing equilibrium
under mild conditions. Illustrative examples are provided to validate the
results.
