Thames Water to boost renewables portfolio to 20%

Thames Water is to generate 20% of its energy requirements through renewable sources with the installation of pre-conditioning plants for anaerobic digestion (AD).


Thames Water to boost renewables portfolio to 20%

Thames Water is to generate 20% of its energy requirements through renewable sources with the installation of pre-conditioning plants for anaerobic digestion (AD).

Pre-conditioned sludge generates higher yields through AD and last year Thames Water saved around £15m off its power bills by generating 14% of its annual energy requirement from sewage.

Effectively industrial-scale pressure cookers which heat up sludge, six new Thermal hydrolysis process (THP) plants will be installed at Thames Water’s main sewage works by 2015.

Along with other renewable energy activities including solar power, Thames Water hopes these new installations will increase the company’s renewable energy generation to 20%.

Thames Water director of capital delivery Lawrence Gosden explained that when using anaerobic digestion alone, about 45% of the organic material in sludge turns into biogas whereas using thermal hydrolysis increases this to between 60 and 65%.

In addition, using THP means there is less solid matter left over at the end of the process, reducing the number of lorries needed to transport it by half. This will save the company around £2m every year.

The new THP plants will be installed at Beckton and Riverside sewage works in Essex, Crossness in Thamesmead, Longreach in Barking, and Oxford and Crawley sewage works.

Gosden said: “This investment is good for the environment, our business and our customers. For as well as being environmentally friendly, generating energy from waste also reduces our running costs by protecting us from the price fluctuations of the mainstream, non-renewable energy markets, bringing savings that help to keep customers’ bills down.”

By generating its own power through sewage and solar panels, Thames Water has reduced its carbon emissions by 16% on 1990 levels and it is aiming for a 20% reduction by 2015.

Conor McGlone

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