- European Union Portal
- European Commission Research
http://sunbird.jrc.it/pvgis/apps/radmonth.php?lang=en&map=europe
- AGORES - A Global Overview of Renewable Energy Systems
- BSW - German Solar Industry Association
- CADDETT Renewable Energy (IEA/OECD)
- European Photovoltaic Industry Association (EPIA)
- International Energy Agency (IEA) - Photovoltaic Power Systems Programme
- PHOTON International - The Photovoltaic Magazine
- Renewable Energy Access.com - Renewable and Solar Energy News
- Renewable Energy World - James & James Science Publishers
- Sacramento Municipal Utility District (SMUD) - Solar PV Pioneer Programs
- Solarbuzz - Portal to the World of Solar Energy
- SolarPlaza - The global solar PV marketplace
www.energie-cites.org
http://www.enr-network.org/