Children will be able to see how much energy a new solar panel on their school's roof is saving via digital display boards.
Classrooms at Merlin Primary in Downham, Bromley, have been fitted with the visual aids so pupils can learn about the importance of energy saving.
The large panel, which cost £28,000, should generate enough electricity to run 77 lights.
It was funded by Lewisham council and the Department of Trade and Industry.
The information is also being shown on the school's website.
Head teacher Anthony Peltier said: "The problems we face with climate change have been widely reported in the press. But there's no point in just talking about it. We have to take action now.
"I am extremely proud of what has been achieved. This is a huge asset for the local community and I hope it sets a precedent that will motivate other communities across the world to take up the challenge."
Steve Bullock, Mayor of Lewisham, said: "By creating an environmentally friendly learning culture for children we're changing attitudes of people toward climate change for the future."