ASTM E2939-13(2023)

1.1 This practice provides procedures for determining the expected capacity of a specific photovoltaic system in a specific geographical location that is in operation under natural sunlight during a specified period of time. The expected capacity is intended for comparison with the measured capacity determined by Test Method E2848.

1.2 This practice is intended for use with Test Method E2848 as a procedure to select appropriate reporting conditions (RC), including solar irradiance in the plane of the modules, ambient temperature, and wind speed needed for the photovoltaic system capacity measurement.

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.