NREL Updates Solar Radiation Database
November 27, 2012
The U.S. Department of Energy’s (DOE) National Renewable Energy Laboratory (NREL) and
collaborators released a 20-year updated version of the U.S. National Solar Radiation
Database, a web-based technical report that provides critical information about solar
and meteorological data for 1,454 locations in the U.S. and its territories.
The updated database covers 1991-2010 and includes data from 2006-2010 for the first
time. It also features improved cloud algorithms for modeling solar radiation data,
and an improved State University of New York (SUNY) model for gridded data based on
The database, which tracks hourly solar and meteorological parameters, is widely used
by solar system designers, building architects and engineers, renewable energy analysts
and others to plan, size and site solar electric systems.
The National Solar Radiation Database (NSRDB) provides solar resource information
to industry in support of central solar power plant and distributed rooftop feasibility
studies, economic analyses and research. The database also underlies other industry
data and tools, including NREL’s Typical Meteorological Year (TMY) data sets, PVWattsTM calculator, Solar Power Prospector and System Advisor Model (SAM).
The project was completed in collaboration with Clean Power Research and the National
Climatic Data Center (NCDC). This update, which supersedes the 1961-1990 and 1991-2005
NSRDB releases, is available in three forms:
- A station-based data set at the 1, 454 Weather Service stations (860 of the stations
have serially complete data records).
- A 10 km gridded data set (the Clean Power Research SolarAnywhere® v2.2 product based
on the SUNY model) for the continental U.S and Hawaii from 1998-2009 (solar radiation
values only). NREL has filled gaps in this data set, and the NSRDB version is serially
- A solar-only enhanced research data set for the 1,454 weather observing stations.
A copy of the 1991-2010 report can be viewed and downloaded without cost on the NCDC
The NSRDB solar data fields include global horizontal, direct normal, and diffuse
horizontal irradiance. The NSRDB also features a 20-year summary with statistics (monthly/annual,
diurnal, and persistence) for the 860 serially complete stations.
NREL has applied uncertainty estimates to each hourly data record to help users determine
the suitability of data for each application. Station data are broadly classified
based on uncertainty as Class I, II and III. The first two classifications segregate
serially complete stations by data of higher and lower quality respectively; Class
III stations have data gaps in the period of record, yet hold enough data in the time
series to support many applications.
NREL is currently in the process of updating the Typical Meteorological Year data
sets using data from the NSRDB update.
Steve Wilcox, National Renewable Energy Laboratory
NREL is the U.S. Department of Energy's primary national laboratory for renewable
energy and energy efficiency research and development. NREL is operated for DOE by
the Alliance for Sustainable Energy, LLC.