Roscommon County Council will save around €40,000 a year in electricity bills through a solar energy project.
The panels have now been installed on the local authority's headquarters.
A project to increase the energy-efficiency of Áras an Chontae in Roscommon town was finished in the first three months of this year.
This included the installation of 180 solar photovoltaic panels on the roof of the building.
All light fittings were also replaced with LED lights.
It's estimated these measures will save the council around 140,000 kilowatt hours of electricity a year.
This is enough to power around 33 homes and will save the council around €40,000 a year.