Power and renewables

Solar Resource Compass

Solar Energy on Demand

Reduced irradiance uncertainty, smarter site decisions

Irradiance data is available from many sources, but there is considerable variation in the estimates available from both free and paid irradiance data providers. At many project locations, the spread between the highest and lowest estimates can exceed 10%. This misalignment between data sources creates uncertainty in the solar energy modeling process. Users who rely on a single source for irradiance data may estimate high at some locations, and estimate low at other locations. To reduce the risk of selecting data that is too optimistic or too pessimistic, Solar Resource Compass allows the user to easily compare irradiance data for each project location. 

Learn more about using the tool:

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Solar Resource Compass accesses and compares irradiance data from multiple data providers and allows you to see how they compare for your project location. By default, Solar Resource Compass will access data from NREL (satellite and MTS datasets), Meteonorm and DNV GL’s SunSpot irradiance model. The results of the analysis include a statistical comparison of the available sources presented in a convenient table, chart and map.

Solar Resource Compass automatically includes data from DNV GL’s own satellite-derived irradiance model, SunSpot. SunSpot data gives you an additional irradiance data source to include in the comparison and includes TGY and historical data at 1 km resolution in 1 hour or 15 minute intervals.

DNV GL’s Solar Resource Compass can be used during the site screening process to assess the spread in irradiance estimates for your site. The service can also be used when evaluating projects during financing or acquisition to evaluate whether the estimated irradiance may be optimistic. This can improve the site selection process and reduce the likelihood of misalignment between development phase assumptions and financing/re-financing assumptions.

Access to Solar Resource Compass is available as a subscription, allowing you to choose an access level that is appropriate for your volume of projects.


  • Comparison of monthly and annual irradiance data for at least 5 nearby NREL stations, plus NREL’s PSM satellite model, Meteonorm and DNV GL’s SunSpot irradiance data.
  • DNV GL SunSpot TGY irradiance data for your project location: 1 km tile, includes GHI, DNI, DHI, ambient temperature and wind speed.
  • Meteonorm TMY irradiance data for your project location.
  • Ability to upload your own datasets.
  • Quality check of each source to ensure that GHI, diffuse, temperature and wind speed are consistent among the group. Outliers are flagged so you can see which sources passed the quality checks and which did not.
  • Summary analytics including median/average values, standard deviation and uncertainty.
  • Information about each source including distance from site, grid size (for satellite data) and elevation.
  • Map-based view allowing you to evaluate where stations are location relative to your project location.
  • Monthly summary table reporting GHI, DHI, temperature and wind speed.
  • Charting of the GHI for each source to evaluate monthly/seasonal consistency.
Schedule a demo with us to learn more about the tool.

Contact us:

Jackson Moore

Jackson Moore

Head of Section, Solar Technology

Try the tool for free

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