Work has started on a multimillion-pound project to fit homes in Cornwall with ground-source heat pumps that have been made in the county.
About 250 homes are to benefit from the £6.2m project, with pumps being first installed in the village of Stithians, where many rely on heating oil.
The pumps cost about £20,000 each, but the project by manufacturer Kensa is being paid for by European funding.
Heating homes accounts for 30% of the UK's carbon emissions.
The Heat The Streets project has been given £6.2m from the European Union's European Regional Development Fund (ERDF) and is seeing systems being rolled out to homes of different numbers of bedroom and ages in the village.
Project manager Lisa Treseder, from Kensa, said the work would mean cheaper bills "especially for people that are on oil and... even more for people that have got electric storage heaters".
Parish councillor Phil Blease, who helped bring the project to Stithians, said it was an attitude of "we're all in this together and we've all got to do our bit".
He said: "We have been very successful in doing that, and inspired a lot of other energy groups and communities."
Future plans include creating communal grids of underground pipes to source heat that people could hook into to heat homes in a carbon-friendly way, project bosses said.