Cost, CO/sub 2/ emission, and primary energy consumption of a microgrid

The microgrid concept is expected to be widely implemented in the coming years. To increase renewable energy near the demand side, a microgrid is proposed that utilizes controllable prime movers such as gas engines to compensate fluctuating demand and output of renewable energy. First, we modeled the optimal operation planning of a hybrid generation system for the day ahead based on 30-minute demand data. Then, we compared the difference in operation pattern based on three different objective functions, namely, minimization of either the running cost, CO2 emission, or primary energy requirement. Finally, we did a sensitivity analysis of the annual cost of the microgrid to the battery capacity and contracted electric power demand from a utility grid. In conclusion, effective reduction of the annual cost of the microgrid requires minimizing the contracted demand.