Metering DC coupled Distributed Energy Resource systems

The prevalence of distributed energy resources (DER) presents challenges to traditional utility metering schema. Energy consumption and demand are valuable data when planning the size and growth of electrical systems from a reliability perspective. Some utilities meter the output of the DER inverters, in order to provide generation data to the customer and adequately plan for reliability. A DER solution which supports storage and essential load when utility power is lost, which is an attractive characteristic, presents a challenge to the traditional solution of metering the AC output of the inverter. The authors investigate alternative metering solutions for these situations, and present the benefits and drawbacks of each.