INVERTERS ARE A CRITICAL COMPONENT FOR GENERATING PV ELECTRICITY. THEY HAVE BEEN IDENTIFIED AS THE LARGEST SOURCE OF CORRECTIVE MAINTENANCE AND DOWNTIME IN LARGE-SCALE PV PLANTS. SEMINAL RESEARCH ON DOCUMENTING INVERTER FAILURES INDICATES THAT ELECTRICAL COMPONENTS ARE, CUMULATIVELY, THE BIGGEST CULPRIT. EXTENDING COMPONENT LIFETIME TOWARDS IMPROVING INVERTER RELIABILITY IS IMPORTANT FOR NUMEROUS REASONS, INCLUDING: CONTINUING TO REDUCE TO THE LEVELIZED COST OF ENERGY (LCOE) FROM PV PLANTS AND INCREASING RELIANCE ON INVERTER-BASED RESOURCES TO PROVIDE GRID SUPPORT AS PENETRATION LEVELS INCREASE. IMPROVING INVERTER RELIABILITY IS ALSO IMPORTANT TOWARDS ACHIEVING THE 2¢/KWH LEVELIZED COST OF ELECTRICITY (LCOE) TARGETED BY SETO, ESPECIALLY FOR THE VISION OF 50-YEAR SERVICE LIVES FOR PV PLANTS. THIS PROJECT USES A MIX OF FIELD-BASED AND LAB-BASED TESTING TO BETTER UNDERSTAND INVERTER FAILURE MODES, IDENTIFY OPPORTUNITIES FOR IMPROVING INVERTER RELIABILITY, DEVELOP SERVICE LIFETIME ESTIMATES AND PREDICTIVE MAINTENANCE FOR INVERTERS, AND ESTABLISH BEST PRACTICES FOR INVERTER-FOCUSED RETROFITTING AT LARGE-SCALE PV PLANTS.