Photovoltaic module performance measurements traceability: Uncertainties survey

The performance of a photovoltaic module is mainly defined by the maximum power Pmax, which is measured under standard conditions (1000 W/m2, AM 1.5, 25 °C) using a sunlight (natural or simulated) and a calibrated reference device. This reference photovoltaic device, placed in the same lighting conditions than the module under test, allows the measurement of the sunlight levels through the monitoring of the maximum power of these devices. As a key metric for photovoltaics economy, the measurement of Pmax must be a subject of a strong attention. This paper describes the metrology applied and the typical levels of uncertainties achievable by National Laboratories as well as in the Industry.