Northumberland franchised dealer Blackshaws has invested in more than 100 solar panels for its dealership.
The Nissan and Suzuki dealer, in Alnwick, decided to take action after discovering it was spending more than £30,000 a year on electricity.
The company has had a 30kWh solar PV system, consisting of 122 solar panels, installed at its site by Newcastle-based renewable energy company Eco Environments.
The total payback over 25 years is expected to be around £460k while the annual Co2 saving will be more than 12,000kg.
David Blackshaw, managing director, said: "A survey was done on our lighting consumption which revealed that we could make savings over three or four years of as much as 25%.
"We see it as a very good financial investment which will also significantly reduce our carbon footprint over the coming years."
Blackshaws won AM Awards this month for Best Marketing Initiative and Aftersales Operation of the Year.