Continued improvement in the cost and efficiency of photovoltaic (PV) technology hints at a future in which utilities will need to accommodate high levels of variable distributed generation (DG) on their transmission and distribution systems. The communication connectedness of these diverse, often small-scale devices will be an essential factor in enabling their widespread integration. In fact, the development of a common language for communicating with distributed inverter-based systems, such as solar photovoltaics (PV) and energy storage, has the potential to vastly improve the industry’s monitoring and management capabilities and more competently exploit DG’s aggregate benefits.

Current industry practices for integrating smart, communicating inverters into utility systems are, however, scarce and largely proprietary. As a result, EPRI, along with the U.S. Department of Energy, Sandia National Laboratories, and the Solar Electric Power Association launched a collaborative research project in mid-2009 to begin a consensus-based process of identifying and standardizing a set of grid-friendly inverter/charger capabilities. The project vision included the identification of standards-based communication protocols to manage the functions.

This white paper reports on the collaborative’s latest findings and recommendations, and is intended to solicit public and industry feedback to help progress the research effort. The outcome of the collaborative’s research effort are potentially far-reaching given policy, technology, and economic factors driving increasing development of grid-tied distributed generation. Healthy government incentives such as the Investment Tax Credit (ITC), increasing conversion efficiencies, and falling production costs are helping to drive utility interest in solar PV generation. The potential emergence of a federal carbon emission reduction policy and state mandates, such as Renewable Portfolio Standards (RPS) that create specific requirements for PV, are also spurring the growth of the PV industry.

Meanwhile, storage technologies are also garnering increasing attention. As one example, the nascent electric vehicle industry, which represents a large potential market for high capacity batteries, is driving investment in novel technology concepts. And stationary distributed storage systems are receiving greater attention as they begin to demonstrate the progressive ability to satisfy a range of applications including frequency regulation, emergency backup power, load shifting, peak reduction, var support, harmonics management, and renewable integration...(Read more...)