A Norfolk housing association is investing more than £7m in solar-powered energy for 1,000 of its 4,600 homes.
Saffron Housing Trust will install photo-voltaic (PV) panels on the roofs of the properties in south Norfolk.
The association estimates tenants with an average electricity bill could save £125 a year.
Not all homes will be eligible and one of the main criteria for the free solar panels will be a south facing property.
The roofs also have to be big enough to take a number of panels, have the right slope and not be shaded by large trees or other buildings.
Saffron will take advantage of the government's Feed-in tariff scheme which encourages investment in low carbon electricity in return for guaranteed payment for the electricity generated and exported.