Microgrid for Residential and Office Building with Battery Storage and Central Hot-Water Tank

Abstract

–Renewable                Energy Resources(RER)are becoming a greater fraction of the energy supply, and efficiently delivering this energy to variable loads presents a variety of problems. This paper models a small-scale microgrid consisting of residential and office building with energy supplied from solar panels, battery and hot water tank, and grid as a backup. The load profiles representing one year of building electrical and hotwater energy demand are developed from historical meter data. Electrical demand is supported by battery storage, and hotwater demand is supplied from a central storage tank. A dispatching control algorithm is designed to transfer available renewable power directly to the loads or storage systems, while confirming constraints on power flows and stored energy. For a fixed annual load profile, the proposal goal is to size system elements to minimize cost while maintaining high renewable energy penetration and low renewable curtailment. Renewable energy from a PV array is dispatched to the load or is stored for later use, and the microgrid performance is measured by the renewable energy penetration, renewable curtailment, and system cost over time. Modeling results indicate that replacing some electrical storage capacity with thermal storage for demand hotwater has the potential to decrease cost and increasing renewable. penetration and decrease renewable curtailment.