  A cooperative energy scheduling method is proposed that allows joint energy
optimization for a group of microgrids to achieve cost savings that the
microgrids could not achieve individually. The discussed microgrids may be
commercial entities in a distribution network under utility electricity rate
plans comprising both Time of Use (ToU) and peak demand charge. Defining a
stable operation as a situation where all microgrids would be willing to
participate, it is shown that under such rate plans and in particular due to
the peak demand charge, a cost distribution that is seemingly fair does not
necessarily result in a stable cooperation. These results are derived in this
paper using concepts from cooperative games. It is therefore sought to devise a
stable cost distribution algorithm that, while maximizing some measure of
fairness among the participating microgrids, ensures they all benefit from
their participation. A simple case study is presented that demonstrates
fairness and stability aspects of the cooperation.
