Annual Solar Irradiance Anomaly Features Over the USA During 1998-2017 Using NSRDB V3

Research output: Contribution to conferencePaper

3 Scopus Citations


Annual solar irradiance anomalies (or departures from the long-term mean annual value) have a direct impact on various phases of solar energy projects, from prefeasibility studies to technical deployment decisions. Anomalies can happen because of normal climate variability or exceptional weather patterns. This study investigates such anomalies for both global horizontal irradiance (GHI) and direct normal irradiance (DNI) using Version 3 of the National Solar Radiation Database (NSRDB V3) and surface irradiance measurements at eight U.S. locations. At each site, the annual anomaly is analyzed here by evaluating the irradiance deviation from the long-term average for each specific year from 1998–2017. A positive/negative anomaly indicates that the solar resource was higher/lower than the long-term average during that specific year. The results show that in most cases the anomaly is within ±5% for GHI and ±10% for DNI using either ground-based irradiance measurements or modeled data from the NSRDB.
Original languageAmerican English
Number of pages5
StatePublished - 2021
Event2020 47th IEEE Photovoltaic Specialists Conference (PVSC) - Calgary, Canada
Duration: 15 Jun 202021 Aug 2020


Conference2020 47th IEEE Photovoltaic Specialists Conference (PVSC)
CityCalgary, Canada

Bibliographical note

See NREL/CP-5D00-76858 for preprint

NREL Publication Number

  • NREL/CP-5D00-79301


  • anomaly
  • direct normal irradiance
  • DNI
  • GHI
  • global horizontal irradiance
  • photovoltaic
  • PV
  • resource
  • solar radiation


Dive into the research topics of 'Annual Solar Irradiance Anomaly Features Over the USA During 1998-2017 Using NSRDB V3'. Together they form a unique fingerprint.

Cite this