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Last updated - Dernière modification 21/11/08 Mines ParisTech - Armines |
Uncertainty of the HelioClim-2 Database of Solar Radiation
The uncertainty has been assessed by comparisons with measurements performed in 35 stations of the WMO radiometric network in Europe. The natural variability of the radiation should be removed from the values below (approx. 10-15 %) to evaluate the accuracy of the database. See articles.
| Mean value of ground data | Bias (HC - ground) | RMSE (root mean square error) | |
|---|---|---|---|
Hourly
Values |
357 Wh/m2 1285 kJ/m2 357 W/m2 |
-7 Wh/m2 (2 %) -25 kJ/m2 (2 %) -7 W/m2 (2 %) |
91 Wh/m2 (25 %) 328 kJ/m2 (25 %) 91 W/m2 (25 %) |
Daily
Values |
3384 Wh/m2 12182 kJ/m2 141 W/m2 |
110 Wh/m2 (3 %) 396 kJ/m2 (3 %) 5 W/m2 (3 %) |
482 Wh/m2 (14 %) 1735 kJ/m2 (14 %) 20 W/m2 (14 %) |
A comparison was made between ground measurements (monthly means of irradiance) and estimates from HelioClim-1 v4 (HC1v4) and HelioClim-2 for years 2004-2005. See graphs for