Best Practices for Operation and Maintenance of Photovoltaic and Energy Storage Systems; 3rd Edition

Revision: 3.0
Date: December 2018
The goal of this guide is to reduce the cost and improve the effectiveness of operations and maintenance (O&M) for photovoltaic (PV) systems and combined PV and energy storage systems. Reported O&M costs vary widely based on the requirements of the system and the nature of the O&M contract, but a more standardized approach to planning and delivering O&M has the potential to both decrease costs and make those costs more predictable over time. However, the bigger payoff for improved O&M is increased performance. Actuarial data indicate that comprehensive PV-only system O&M could improve the average performance ratio (PR, adjusted for age and temperature) of systems from 91.7 to at least 95%, which is a substantial increase in revenue and environmental benefits of a PV system (oSPARC 2018). Drivers to improve O&M include the following: increase efficiency and energy delivery (kWh/kW), decrease downtime (hours/year), extend system lifetime (e.g., from 25 to 40 years for PV modules), reduce cost of O&M ($/kW/year), ensure safety and reduce risk, enhance appearance, and meet requirements of financing and warranties.