Solar Measurement and Modeling

NREL supports grid integration studies, industry, government, and academia by disseminating solar resource measurements, models, and best practices.

Text version

These resources are used to design and plan renewable energy systems. Since 1981, NREL’s researchers have continuously gathered basic solar radiation information at the Solar Radiation Research Laboratory, and they now gather high-resolution data in up to 1-second intervals from World Meteorological Organization first-class radiometers and photodiode sensors.


  • Solar resource calibration, measurement, and characterization
  • Solar resource modeling
  • Solar forecasting
  • National and international standards development and best practices dissemination
  • Solar monitoring training and mentorship


The Solar Resource Calibration, Measurement, and Dissemination project supports the Department of Energy SunShot Initiative by improving the tools and methods that measure solar radiation to reduce uncertainty in predicting solar output and thereby lower risk in solar projects. This project seeks to develop and disseminate accurate solar measurement and modeling methods, best practices and standards, and data to stakeholders, including academia, industry, and laboratories.

This project seeks to build on satellite-based modeling to quantify solar resource in the plane of array (POA) for various PV module types. The project will provide technology-specific, long-term PV resource data that will enable increased use of POA measurements, resulting in an improvement in the accuracy of PV plant performance assessment. This increased accuracy will significantly reduce the price of electricity delivered and increase return on investment of a proposed project, thereby increasing the viability of solar projects.


Best Practices Handbook for the Collection and Use of Solar Resource Data for Solar Energy Applications: Third Edition, NREL Technical Report (2021)

A Fast All-Sky Radiation Model for Solar Applications (FARMS): Algorithm and Performance Evaluation, Solar Energy (2016)

Intercomparison of 51 Radiometers for Determining Global Horizontal Irradiance and Direct Normal Irradiance Measurements, Solar Energy (2016)

Modeling Beam Attenuation in Solar Tower Plants Using Common DNI Measurements, Solar Energy (2016)

Radiometer Calibration Methods and Resulting Irradiance Differences, Progress in Photovoltaics: Research and Applications (2016)

A Method to Measure the Broadband Longwave Irradiance in the Terrestrial Direct Solar Beam, Journal of Atmospheric and Solar-Terrestrial Physics (2015)

View all NREL publications about solar measurement and modeling.


Manajit Sengupta

Chief Scientist