Welsh Water turns sludge to power

Welsh Water has commissioned three Advanced Digestion plants which will create electricity from treated sewage sludge.

The plants are based in Cardiff, Hereford and Port Talbot and will produce enough electricity to power a town the size of Caernarfon.

The plants are of particular interest because they are much larger than earlier facilities and the sludge is digested at a higher temperature releasing more methane gas.

The water company has invested around £75 million on the plants and two of them will be self-sufficient in electricity.

Welsh Water says the new plants will save them around £8 million on energy every year and will reduce its carbon emissions by 40,000 tonnes.

The company is aiming to reduce its carbon footprint and generate around 17% of its energy needs from renewable sources by 2015.

As well as recycling sewage sludge to generate electricity, Welsh Water also has five small hydro sites in operation and it is currently developing another five sites.

The company is investing a further £25m in smaller energy generation and energy efficiency schemes including changing pumps and motors to energy efficient models and installing 1000 online electricity meters at wastewater treatment works and pumping stations.

Managing director, Nigel Annett, said: “We are one of Wales’s largest energy users – we spent £34 million last year on gas and electricity – and we are determined to reduce our impact on our environment.”

Alison Brown

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