Welsh Water green energy plant moves a step closer

31 March 2021

A facility close to Dinas Powys that will generate clean, green energy from sewage has taken a step closer towards completion.

Dŵr Cymru Welsh Water has been investing more than £50 million to create a new energy generating facility at its Cog Moors Wastewater Treatment Works. The state of the art Advanced Anaerobic Digestion (AAD) facility, which recover energy from the waste processed at the site and uses it to create electricity, has now entered its commissioning phase.

The construction of the AAD facility will enhance the existing Anaerobic Digestion plant at the site, enabling more gas – known as biogas – to be recovered from the waste. The biogas recovered will then be used in engines to generate the electricity.

Once completed, the AAD will generate enough energy to power the works which will make it an energy neutral site. The energy it will produce would be the same as that needed to power 4,800 homes.

While the AAD is being commissioned, the not for profit utility company will complete the remaining onsite activities – which include the reinstatement of the land around the new facility – which it is anticipated will be completed by the end of May 2021.

Shaun O’Leary, Welsh Water’s Programme Delivery Manager, said: "The advanced anaerobic digester at Cog Moors will improve the way we treat the wastewater at the site, as well as help us to reduce our carbon footprint by producing renewable energy. It will also help keep customer bills down as we will be using our own energy to help power the treatment works.

"The work at Cog Moors has been ongoing since 2018, and we’re pleased to say that it’s nearing completion. The new process for recovering energy from the waste processed onsite will be in full service following the commissioning process, which is anticipated to be completed during the spring.

"The majority of the work has been completed within the site of the treatment works and has not adversely affected protected species or sites of nature conservation importance in the surrounding area. We have been keeping local residents informed throughout this project and would like to take this opportunity to thank them for bearing with us while we have carried out this work."

As a company, Welsh Water is one of the largest energy users in Wales, operating and maintaining a network of 27,500km of water mains, more than 30,000km of sewers, 838 sewage treatment works and 66 impounding reservoirs. In recent years, the company has been looking at ways to generate electricity across its sites. It currently generates 25% of its own energy needs through wind, hydro, solar and advance anaerobic digestion, and plans to be 35% self-sufficient by 2025.

This investment project at Cog Moors Wastewater Treatment Works forms part of the company’s commitment to be carbon net zero by 2050. To date, the company has invested over £200 million into AAD plants across Wales which will help manage the effects of climate changes and reduce its carbon footprint.