Comparison of Solcast TMY data

Compare Solcast historical and TMY products to Solargis, Meteonorm, Vaisala, and free data sources

Historical and Tmy
How does Solcast compare to other data sources?

Our goal is to make your work easier. Part of this is making the best data, making it fast and easy for you to download, and giving you free requests to get you started. But we also want to make it easier for you to understand how we compare to some other data providers.

For more detail read the full comparison of Solcast against some commonly used datasets in the solar development community:

Solcast Solargis Meteonorm Vaisala
Free trial with instant access and data download?
Download wait time 1-9 minutes 5 minutes to 48 hours 1 minute 5 minutes to 24 hours
Mean Bias Error (GHI) 0.0% 0.0% N/A 3.1%
Standard Deviation of Bias (GHI) ± 2.0% ± 2.9% N/A ± 4.9%
90% of sites have bias (GHI) smaller than ± 2.5% ± 4.6% N/A Not published
Mean RMSE (GHI) 16.5% 18.0% N/A 18.47%
Comprehensive, global, independent validation
Validation Sites 46 220 N/A 196
Satellite based estimation as primary method
Global Coverage
Resolution of satellite data used 1-2 km 3-4 km 2-8 km 3 km
10+ years of satellite data at full temporal resolution
Ignores older, less reliable satellites
Suitable for use in steep mountain terrain with local relief over 1000m

Free sources comparison summary

Solcast NSRDB PVGIS
Download wait time 1-9 minutes 1 minute 1 minute
Mean Bias Error (GHI) 0.0% 0.3% 0.7%
Bias Deviation (GHI) ± 2.0% ± 2.7% ± 3.2%
90% of sites have bias (GHI) smaller than ± 2.5% Not Published Not Published
Mean RMSE (GHI) 16.5% 22.9% Not Published
Comprehensive, global, independent validation
Validation Sites 46 9 22
Satellite based estimation as primary method
Global Coverage
Resolution of satellite data used 1-2 km 4-10 km 4 km
10+ years of satellite data at full temporal resolution
Ignores older, less reliable satellites

Historic Data Products

Time Series

The complete suite of irradiance and weather data required for effective monitoring, operation, and forecasting at your large-scale solar farm.

Typical Meteorological Year (TMY)

The complete suite of irradiance and weather data required for effective monitoring, operation, and forecasting at your large-scale solar farm.

Monthly Averages

The complete suite of irradiance and weather data required for effective monitoring, operation, and forecasting at your large-scale solar farm.