A Sustainable Energy Community (SEC) is a community in which everyone works together to develop a sustainable energy system. To do so, they aim as far as possible to be energy efficient, to use renewable energy where feasible and to develop decentralised energy supplies.

A Sustainable Energy Community can include all the different energy users in the community including homes, sports clubs, community centres, churches and businesses. SEC's are now being encouraged to join the new SEAI supported SEC Network to help build capacity and share skills across communities.