Southern Water on track for renewables target with new CHP plant

By harnessing human waste to generate electricity, Southern Water hopes to reduce carbon emissions from its Sandown Wastewater Treatment Works by around 1,400 tonnes a year.

The project is part of Southern Water’s multi million pound investment in carbon mitigation and energy efficiency schemes between 2010 and 2015.

The company, which supplies 551 million litres of drinking water to customers each day, has a target of generating 20% of its energy usage from renewable sources by 2020 and it believes these schemes will contribute to meeting its goals.

Southern Water has invested £700k on installing a Combined Heat and Power (CHP) plant at its Sandown works to capture bio-gas created during the treatment process.

This gas, which would otherwise have been burnt off in a flare, can then be used to produce renewable energy and any surplus is exported to the National Grid.

As well as generating electricity, the CHP plant also recovers heat from the engine and exhaust systems via water from heat exchangers. This water is then used to warm the treatment tanks, helping speed up the bacterial digestion of the waste.1

The installation is expected to be completed in the spring.

Southern Water already converts waste to energy at 13 of its wastewater treatment works through the use of CHP plants.

Southern Water project manager Morné Cloete 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.”

Conor McGlone

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