Absorbing the Rays: Advanced Inverters Help Integrate PV into Electric Utility Distribution Systems

PEPCO HOLDINGS, INC. (PHI) IS one of the largest energy delivery companies in the Mid-Atlantic region of the United States, serving about 1.9 million customers in Delaware, the District of Columbia, Maryland, and New Jersey. PHI's subsidiaries Pepco, Delmarva Power, and Atlantic City Electric (ACE) provide regulated electricity service to these areas. The ACE service territory has a number of renewable distributed energy resources (DER) installations, including landfill gas (methane), wind, and solar. In particular, solar installations in the form of photovoltaic (PV) systems have been increasing due to substantial financial incentives in New Jersey, while Maryland, Delaware, and Washington, D.C. are also seeing activity due to incentives. In New Jersey, large systems are interconnected into the distribution system (12 kV) because the state has required all systems to connect to the distribution system if the system owners wish to earn solar renewable energy certificates (SRECs). Applications for installations in the PHI distribution system range from 1 kW up to 100 MW.