Due to its reduced communication overhead and robustness to failures,
distributed energy management is of paramount importance in smart grids,
especially in microgrids, which feature distributed generation (DG) and
distributed storage (DS). Distributed economic dispatch for a microgrid with
high renewable energy penetration and demand-side management operating in
grid-connected mode is considered in this paper. To address the intrinsically
stochastic availability of renewable energy sources (RES), a novel power
scheduling approach is introduced. The approach involves the actual renewable
energy as well as the energy traded with the main grid, so that the
supply-demand balance is maintained. The optimal scheduling strategy minimizes
the microgrid net cost, which includes DG and DS costs, utility of dispatchable
loads, and worst-case transaction cost stemming from the uncertainty in RES.
Leveraging the dual decomposition, the optimization problem formulated is
solved in a distributed fashion by the local controllers of DG, DS, and
dispatchable loads. Numerical results are reported to corroborate the
effectiveness of the novel approach.