Dear Ghaieth

The software meteonorm 7 is very useful; you can get all the Meteorological data for the entire region around the world.

Dear Dr.Khalifa, thank you. I will definitely try it.

The Food and Agriculture Organization's freely available CLIMWAT database see http://www.fao.org/land-water/databases-and-software/climwat-for-cropwat/en/ may also be of interest to you. It contains monthly, mean data based on 5,000 climate stations worldwide and includes sunshine hours as well as mean solar radiation. CLIMWAT will contain data for various stations in Italy.

One of the best FREE sources for solar radiation would be https://re.jrc.ec.europa.eu/pvg_tools/en/tools.html#MR

Another good one is http://www.soda-pro.com/web-services/radiation/cams-radiation-service

hello dear network,

I need a parameter "the hourly sunshine duration" to estimate the incident solar radiation on a sloping surface. Could You tell me a database to indicate this parameter ?

Thanks in advance

Firyal LATRACHE

Daily sunshine is a legacy quantity of doubtful accuracy that is not measured any more in many countries. You can find such data from the WRDC repository (http://wrdc.mgo.rssi.ru/), but I doubt you can find hourly sunshine data anywhere.

Actually, you don't need that to calculate solar radiation on a horizontal or tilted surface. Only the irradiance components are needed...

CMSAF

https://www.cmsaf.eu/EN/Highlights/Dokumente/News_27.html

Some useful monthly data for sunshine duration and radiation can be found in WRDC. They have arranged it according to various cities.

http://wrdc.mgo.rssi.ru

From the answers, we learned many useful links. Thanks everyone.