  This paper proposes a peer-to-peer energy trading scheme that can help the
centralized power system to reduce the total electricity demand of its
customers at the peak hour. To do so, a cooperative Stackelberg game is
formulated, in which the centralized power system acts as the leader that needs
to decide on a price at the peak demand period to incentivize prosumers to not
seeking any energy from it. The prosumers, on the other hand, act as followers
and respond to the leader's decision by forming suitable coalitions with
neighboring prosumers in order to participate in P2P energy trading to meet
their energy demand. The properties of the proposed Stackelberg game are
studied. It is shown that the game has a unique and stable Stackelberg
equilibrium, as a result of the stability of prosumers' coalitions. At the
equilibrium, the leader chooses its strategy using a derived closed-form
expression, while the prosumers choose their equilibrium coalition structure.
An algorithm is proposed that enables the centralized power system and the
prosumers to reach the equilibrium solution. Numerical case studies demonstrate
the beneficial properties of the proposed scheme.
