Using anaerobic digestion, the plant will produce renewable energy to power and heat the works, while surplus electricity will be exported to the power grid.
The CHP plant will also use heat from the engine and exhaust systems to warm treatment tanks and speed up the bacterial digestion of the waste.
The project, due to be up and running by spring this year, forms part of Southern Water’s programme to self-generate 20 per cent of its electricity needs from renewables sources by 2020. The company also hopes to the CHP plant will reduce its carbon emissions from the site by around 1,400 tonnes a year.
Morné Cloete, Southern Water project manager, said: “Harnessing recoverable energy through the use of CHP plants is just one of the innovative ways Southern Water is helping reduce its impact on the environment by reducing our carbon footprint while also cutting our energy costs.”