A water company is aiming to become Britain's biggest producer and industrial user of solar power.
Thames Water has agreed a deal which will lead to the installation of solar panels which will provide an annual output of more than 4,500 megawatt hours (MWh) of electricity, which is enough to run about 970 average-sized homes.
Thames Water estimates the scheme will shave £100,000 a year off its £80m energy bill.
The panels will be fitted in three sites across London: on the roof of the Beckton desalination plant in Newham, on storm tanks at Crossness sewage works in Bexley and on redundant sand filters at Walton water treatment works in Sunbury.
The scheme will see Ennoviga Solar, a specialist photovoltaic developer, maintain the panels, repaying the £7m investment by selling all the clean electricity produced to the water company at a competitive price.
Dr Piers Clark, commercial director at Thames Water, said: "With the price of energy forecast to increase above inflation, the way we've structured this agreement will give us a cheaper, renewable source of power from a secure source over the long term.
"We think this is the right thing to do for our 14 million customers and to help move Britain that little bit closer to becoming a low-carbon economy." PA