How long will the solar electric system last?

While photovoltaic systems are very reliable and long-lived, the inverter is the piece of equipment with the most likelihood of needing repair, maintenance or replacement within the initial 20-year time frame of the system. For this reason, an inverter replacement in year 15-20 should be considered part of any buyer’s long term ownership O & M cost plan. With modern inverters, however, complete replacement will not be necessary as much as replacement or repair of some circuit boards or components.