Balancing supply and demand in the electrical
grid is a challenge for uncoordinated producers and consumers.
This work considers a portfolio of units for power production
as a graph which nodes are distributed generators, and presents
a distributed optimization scheme for optimal usage of the
portfolio for electrical power balancing. We include consumers
with controllable consumption as an active part of the portfolio.
It will be shown that a suboptimal, but arbitrarily good power
balancing can be obtained in an uncoordinated, distributed
optimization framework, even when accounting for limited
computation time. We further show how the number of units in
the portfolio can be increased in a modular way that requires
no change of the overall algorithm.