Northampton Saints has become one of the first major sports clubs in the UK to install solar panels to help power the ground.
The 200 panels are being put on the Burrda Sport Stand’s roof at Franklin’s Gardens.
Chief executive Allan Robson said as electricity prices were rising it “made sense” to look at alternative sources of energy.
Friends of the Earth said it hoped other sports clubs would follow suit.
Northampton Saints said the solar panels would contribute towards powering the stadium, training ground and administration offices and any leftover power would be sent to the National Grid.
The club carries out other green initiatives, including irrigating the team’s pitches with water from a nearby lake.