Developing a "next generation" PV inverter

The most serious reliability issue for photovoltaics (PV) is the inverter. Mean time to first failure (MTFF) is estimated to be about five years. Recent efforts to rapidly expand the production of grid-tied inverters have not resulted in improved reliability. At this time the inverter industry is uniquely positioned to develop a ´next generation´ inverter that has ten-year MTFF, better performance and lower cost. The recent advents of new technologies such as DSP (digital signal processing), the growth in sales to a few hundred thousand inverters per year and the emergence of larger companies with interest in PV inverters make this possible today. At this time the Department of Energy is considering the development of a new inverter for use in distributed energy applications. This report summarizes the status of power electronics today, identifies technology issues, and identifies inverter manufacturer attributes thought to be essential for the production of a ten-year lifetime inverter.