Independent comparisons of solar irradiance models

In this document

We will introduce you to independent evaluations that play a crucial role in assessing solar data and software providers. These evaluations offer an unbiased comparison across different models and providers, helping to identify strengths and weaknesses without potential conflicts of interest.

Worldwide Benchmark of Modeled Solar Irradiance Data (2023)

Description: The International Energy Agency (IEA) recently released the report “Worldwide Benchmark of Modeled Solar Irradiance Data 2023”, developed through a collaborative effort by international solar energy experts under Task 16 of the IEA PV Power Systems Programme. This task, titled “Solar Resource for High Penetration and Large-Scale Applications”, benchmarks model-derived direct normal irradiance (DNI) and global horizontal irradiance (GHI) data across 129 globally distributed ground-based measurement stations.

Results: Among all evaluated models, Solargis consistently achieved the lowest average deviation metrics. The benchmark revealed significant performance variations between modeled datasets. Models based on geostationary satellite imagery displayed closer deviation metrics compared to NWP-based and polar satellite-based datasets.

Evaluated models: Solargis, ACCESSG3, CAMS_pre-v4, CAMS_v3.2, CERES, CSIRO HIMAWARI, DWD SARAH, KNMI SEVIRI, Meteotest, NSRDB GOES.

Authors: Anne Forstinger (CSPS), Stefan Wilbert (DLR), Adam R. Jensen (DTU), Birk Kraas (CSPS), Carlos Fernández Peruchena (CENER), Christian A. Gueymard (Solar Consulting Services), Dario Ronzio (RSE), Dazhi Yang (Harbin Institute of Technology), Elena Collino (RSE), Jesús Polo Martinez (CIEMAT), Jose A. Ruiz-Arias (Uni Malaga), Natalie Hanrieder (DLR), Philippe Blanc (MINES ParisTech), Yves-Marie Saint-Drenan (MINES ParisTech).

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IEA Satellite Data Validation Study (2014)

Description: This study validated satellite-derived GHI and DNI data across 18 locations in the European and Mediterranean regions, covering hourly, daily, and monthly values over up to 16 years. Locations spanned diverse climates, from desert to oceanic, with altitudes ranging from sea level to 1580 meters.

Results: Solargis was identified as the data source with the lowest overall bias, mean bias deviation, and RMSD among all evaluated models.

Evaluated models: Solargis, Meteonorm 7, NASA-SSE, CM-SAF, ESRA, Helioclim, Heliomont, IrSOLaV, PVGIS-CM SAF, RetScreen, Satellight, Solemi, WRDC.

Authors: Pierre Ineichen, University of Geneva.

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IEA SHC Task 36 Data Inter-Comparison Study (2011)

Description: In this study, GHI and DNI data from five satellite-derived irradiation databases were compared with measurements from 23 locations in Europe, the Middle East, and Africa for the year 2006.

Results: The study showed Solargis as the source with the lowest bias and RMSD values among all validated data sources.

Evaluated models: Solargis, SoDa Helioclim, 3Tier (Vaisala), IrSOLaV, University of Oldenburg (EnMetSol-Solis and EnMetSol-Dumortier).

Authors: Pierre Ineichen, University of Geneva.

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Comparison of Annual GHI Maps for Australia (2018)

Description: This study compared annual GHI data for Australia across multiple models, including Solargis, Meteonorm 7.2, NASA POWER, and others.

Results: Solargis demonstrated the lowest bias and RMSD values among validated data sources.

Evaluated models: Solargis, BoM, MERRA-2, NASA, and others.

Authors: Jessie K. Copper and Anna Bruce, University of New South Wales.

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