This study investigates calibration responsivities provided by NREL's broadband outdoor radiometer calibration (BORCAL) and a few prominent manufacturers. To establish or understand the differences in calibration methodology, we processed and analyzed field-measured data from these radiometers. Some of these radiometers are calibrated indoors and some outdoors. This study addresses the effect of different calibration methods provided by radiometric calibration more » service providers, such as NREL and manufacturers of radiometers, on the resulting calibration responsivity. The accuracy of solar radiation measured by radiometers depends on the instrument performance specification, installation method, calibration procedure, measurement conditions, maintenance practices, location, and environmental conditions. Accurate solar radiation data sets reduce the expense associated with mitigating performance risk and assist in understanding the impacts of solar resource variability. Furthermore, utility planners and grid system operators need to understand the impact of the variable solar resource on solar energy conversion system performance.

Further advancing procedures for precisely calibrating radiometers to world reference standards that reduce measurement uncertainties will help the accurate prediction of the output of planned solar conversion projects and improve the bankability of financing solar = ,īanks financing solar energy projects require assurance that these systems will produce the energy predicted. Here by analyzing these differences will ultimately assist in determining the uncertainties of the field radiometer data and will help develop a consensus on a standard for calibration. These different methods of calibration resulted in a difference of ☑% to ☒% in solar irradiance measurements. To establish or understand the differences in calibration methodologies, we processed and analyzed field-measured data from radiometers deployed for 10 months at NREL's Solar Radiation Research Laboratory. Some of these methods calibrate radiometers indoors and some outdoors. This study addresses the effect of different calibration methodologies and resulting differences provided by radiometric calibration service providers such as the National Renewable Energy Laboratory (NREL) and manufacturers of radiometers. Accurate solar radiation measured by radiometers depends on instrument performance specifications, installation method, calibration procedure, measurement conditions, maintenance practices, location, and environmental conditions.

Radiometer point measure