Funding Opportunity: SuNLaMP
SunShot Subprogram: Photovoltaics
Location: National Renewable Energy Laboratory, Golden, CO
Amount Awarded: $4,500,000

Photovoltaic (PV) system degradation rates are not currently assessed in a comprehensive, standardized manner and do not account for climate, mounting configuration, or technology details. This project will develop standardized methods for determining degradation factors, which will reduce the perceived and actual financial risk associated with PV deployment. In addition, partially shaded PV system performance models will be validated and added to PV performance simulation software used by installers, increasing the accuracy of performance prediction. The project will also expand the geographically diverse PV performance database using the microinverter data.


This project will develop standard methods of calculating and reporting field degradation rates and characteristics and transmit these methods to the International Electrotechnical Commission (IEC) to eventually become a standard. Correlations between climate, mounting configurations, and other system parameters will provide additional insight into PV system degradation. Partial shading models will be validated on a variety of systems and added into the Solar Advisor Model (SAM) used by PV installers. Additionally, microinverter data will be validated using existing PV performance measurements and then collected from a variety of geographic locations to expand the PV performance database.


The new standard method for calculating degradation profiles will provide the ability for multiple analysts to apply the method and obtain reproducible rates of degradation, which will enable more accurate PV performance prediction throughout the module lifetime and lower the risk.