Over the years, CEG has received support from the following organizations and foundations:
- Annenberg Foundation
- Basel Agency for Sustainable Energy
- Bipartisan Policy Center
- Carbon Trust
- Citigroup Foundation
- Educational Foundation of America
- Emily Hall Tremaine Foundation
- Energy Foundation
- Heinrich Böll Foundation
- Jane's Trust
- Lenfest Foundation
- National Association of State Energy Officials
- National Renewable Energy Laboratory
- New York Community Trust
- Oak Foundation
- Rockefeller Brothers Fund
- Surdna Foundation
- The Bullitt Foundation
- The Canaday Family Charitable Trust
- The John Merck Fund
- The Pew Charitable Trusts
- Turner Foundation
- U.K. Department for International Development
- U.K. Department of Energy and Climate Change
- U.S. Department of Energy
- U.S. Environmental Protection Agency
- United Nations Environment Programme
- Wells Fargo Foundation
- World Bank