Solar panels at seven major sites operated by Sembcorp Bournemouth Water (SBW) are expected to save carbon dioxide emissions equivalent to taking 134 cars off the road.
The panels have been newly installed at SBW's Alderney, Christchurch, Fordingbridge, Horton, Longham, Ringwood, and Wimborne sites.
The installation process of the 960 panels took some six months to plan and connect into the water supply company's existing electrical infrastructure.
SBW uses in the region of 30 million kilowatt hours (kWh) of electricity per annum to pump 150 million litres of water each day to about 185,000 households and 16,500 businesses in Dorset, Hampshire and Wiltshire.
The company say that the installed panels will generate more than half a million kilowatt hours of electricity per annum, equivalent to the boiling of ten million kettles of water.
When the generated power from the solar panels is not required for pumping, the excess electricity is automatically diverted into the National Grid.
SBW calculate the panels will save 285 tonnes of carbon dioxide being released into the atmosphere which is equivalent to taking 134 small family cars off the road.
Roger Harrington, SBW's Managing Director, said: "Supplying water is a very energy intensive business. We pump about 150,000 tonnes of water to our customers every day.
"The use of solar panels on our sites has reduced the amount of electricity we need to take from the grid and hence our impact on the global environment."
SBW supplies drinking water to approximately half a million people through a system of seven major treatment works and a network of about 2,800 kilometres of water main.
Three quarters of the water is abstracted from the Rivers Avon and Stour and the remainder comes from borehole sites.
The picture shows Peter Ferenczy, Sembcorp Bournemouth Water's Asset Manager (right) with Derek Jones of energy services company Anesco