Major UK Water Company’s Invests in Anaerobic Digestion of Sewage Sludge

The following article is based on an extract of Wet News (November 2008) the original article is about work done by May Gurney to refurbish and improve the current Severn Trent Coalport, Newport and Monkmoor, anaerobic digesters which digest sewage sludge:

AS NEW energy and environmental directives come into action, the UK sewage treatment industry is increasingly under the spotlights.

Many examples of renewable energy projects by the gigantic water firms and their framework partners are reported to be on their way which will be almost guaranteed to draw much interest from politicians, rivals and the public. Combined heat and power (CHP) is at the forefront in the UK Water Industry, manufacturing heat and electricity from a single input source that might otherwise be burned off as waste.
Severn Trent Water and May Gurney completed an intensive project to install new anaerobic digestion technology on 3 of Severn Trent's sites. The water company has been working in cooperation with contractor May Gurney, a consultant in biogas optimisation, which has been carrying out these works since 2007.

Last summer when the article was writted it was getting near completion on the last site located at Coalport, Shropshire. The other 2 sites, at Newtown ( Powys ) and Monkmoor, Shrewsbury ( Shropshire ), were handed back this summer and are manufacturing biogas from their improved digester systems and using it to fuel CHP units.

The work at Newtown, Monkmoor and Coalport has enabled the sites to scale back their carbon footprints and produce green energy. Doing so will also prove very much a bargain as Severn Trent will become more self-sufficient and save heavily on external energy suppliers' ever growing costs.

At Coalport alone, the median daily sludge feed to the digesters is 129m3, which produces a mean of 2,640m3 of biogas each day - enough to power the on-site CHP units that generate electricity to run the site as well as the heat to operate the boilers and continue the digestion process.

The authors of the article see a huge future for biogas.
"For all the same environmental, legislative and commercial reasons that have inspired Severn Trent Water, others will certainly follow suit," and they are saying, much more positive things about Anaerobic Digestion, as follows:

"We are happy about the possibilities for expansion and development in this area. A complete industry is expanding round the re-emergence of anaerobic digestion, which enables waste material, eg food waste, to be used as a resource to provide replenish-able energy.”

"The giant increase in available volumes of biogas, rising oil costs, increasing demand for new renewable fuels and bio energy will excite investment in biogas utilization technologies which will see biogas refining to be used as auto fuels or injection into the nation's grid.”

"This latter opportunity will definitely not have escaped the notice of water firms. While sites with anaerobic digestion processes already benefit from self-sufficiency by manufacturing their own energy, we need only look to states like Sweden to see examples of how extra revenue can be generated by selling electricity and bio-methane and at the same time make a contribution to govt. climate change, waste management and wider environmental objectives."

In the field of renewable resources the authors say that Severn Trent is sure to be at the forefront as the industry moves in this direction. As the number 1 producer of renewable energy in the water sector, Severn Trent is progressing with its investment programme to further develop greener energy.

Having set itself the target of just about doubling self-generation from renewable resources to thirty percent of its total energy use by 2013, Severn Trent has clear plans to develop usage of existing technologies as well as introduce new and emerging technologies.

Severn Trent operates thirty CHP plants across its area using methane gas produced from the sewage treatment process. In 2005, this accounted for 51 percent of all clean energy derived from sewage gas in the United Kingdom and about 1.3% of all clean energy generated in the United Kingdom.

Current investment plans are reported to include schemes to increase the use of CHP plants across the region, install more water turbines in its dams, generate power from energy crops, and generate power from turbines at acceptable locations.

Furthemore, that investment is reported to be ongoing as a consequence of the success of the Monkmoor, Newtown and Coalport projects, the company has, we undertand, been in advanced talks with May Gurney about another 9 CHP projects.

More about May Gurney.