Carmarthenshire County Council plans to procure private partners to deliver roof-mounted photovoltaic panels with battery storage systems on social housing units.
The council is assessing the viability of the project with social housing providers to install the technology on around 25,000 properties in the Swansea Bay City Deal area to provide tenants with renewable energy and lower bills.
The authority plans to publish a contract notice at the end of March 2018.
Meanwhile, commune de Saint-Rémy-de-Provence is seeking partners to design, build, finance and operate a photovoltaic power plant in southern France on a €7.9m contract.
Interested parties have until midday on 21 November to submit responses.