UK's First Energy Self-Sufficient Large Sewage Works

Yorkshire Water are embarking on a multi-million pound project to create the UK's first energy neutral urban sewage plant.

Starting today, this £30 million project will involve installing the UK's first BioThelys Sludge Treatment Plant at Esholt sewage works, which will be used to create energy from human waste and effluent.

The Esholt works has operated a sewage sludge incinerator for many years, but Yorkshire Water is pioneering a more sustainable route for sludge disposal using Veolia's thermal hydrolysis system (Biothelys) combined with anaerobic digestion.

Thermal hydrolysis uses heat and pressure to break down sewage sludge prior to treatment by anaerobic digestion which creates energy rich biogas that can then be burned to produce electricity which in turn will be used to power much of the plant.

As the bio-gas is rich in methane, it means that it can be converted to electricity and directly used to power the site, the process is carbon efficient and means the plant is not reliant on mains electricity, further reducing costs.

Not only does the process create green energy to fuel the plant, but the digested sludge generated following thermal hydrolysis is classified as 'enhanced treated' which means it can be legally applied as a fertiliser or soil conditioner for all crops including cereals, vegetables and salads as well as for horticultural purposes.

Engineering specialists Morgan Sindall and Grontmij will be undertaking the work, with the new plant estimated to take around 18 months to complete, and is expected to be commissioned in early 2013.

Ben Roche, Manager of energy and carbon at Yorkshire Water, comments:

"At the moment we already generate a third of the energy we use on site at Esholt through renewable energy technologies, but our aim is for this huge facility to become fully energy self-sufficient by 2015."