Solarserver
German homepage for solar energy, also in English

German WindEnergy Association

US website for renewables

Earthscan
Publisher of sustainable development publications, big database of RES companies

Hungarian Biomass Association

Hungarian Geothermal Association

The European Network for Energy Economics Research

European Wind Energy Association

World-wide Information System for Renewable Energy

Energy Information Portal
Homepage of the U.S. Department of Energy - renewables and energy efficiency

Hungarian Biogas Association

Energy Best Practice database
Online database presenting successful renewable energy investments from the Central European Region

European Renewable Energies Federation (EREF)
EREF is the European interest and lobby group for independent producers of electricity and fuels from all renewable energy sources except large hydro.

European Renewable Energy Council (EREC)
EREC is the umbrella organisation of the European renewable energy industry, trade and research non-profit associations active in the sectors of bioenergy, geothermal, ocean, small hydropower, solar electricity, solar thermal and wind energy.