- Acadia Center is a non-profit focusing on research and advocacy for clean energy. They are an invaluable source of research and policy recommendations for CT. They have an office in Hartford.
- Beyond Nuclear is an excellent source of information about nuclear energy and arms. A tireless and effective advocate or a world free of both, Beyond Nuclear was co-founded by Lou Friedman, wife of Judi, who led PACE for over forty years.
- Clean Coalition Based in Palo Alto, CA, the mission of the Clean Coalition is the promotion of renewable energy and a modern electric grid. Their staff includes not only policy experts but also engineers. They have particular expertise in Community Microgrids.
- Connecticut Clean Water Action
- Connecticut Fund for the Environment
- CT Roundtable on Climate and Jobs Formed in 2012, the Roundtable is a diverse collaboration of the Inter-Religious Eco-Justice Network (IREJN) and the CT AFL-CIO. The Roundtable, led by John Humphries, is an effective advocate for clean energy and jobs in the state.
- Eastern CT Green Action is a network of local groups in Eastern CT devoted to reducing climate change through action at the local and state level.
- Sierra Club, Connecticut Chapter