Severn Trent invests £60m in thermal hydrolysis plant

Water company aims to generate 50 per cent of the energy it uses by 2020

Severn Trent has invested £60 million in thermal hydrolysis technology to generate 30 per cent more clean energy at its biggest sewage treatment works in Minworth, near Birmingham.

The company said the Thermal Hydrolysis Plant (THP) is starting to “take shape” and the scheme will make the way it treats waste more efficient.

David Nyul, project manager for Severn Trent, said: “Generating clean energy through anaerobic digestion is a real priority for us and we’ve been treating sewage in this way for the last 60 years.

“The deployment of this latest generation of thermal hydrolysis technology will make that process more efficient and means we can take 30 per cent more energy out of the waste we treat.”

He added: “Across the company we currently generate around 34 per cent of all of the energy we use as a business, and the thermal hydrolysis process will move us closer to our target of making that 50 per cent by 2020.”

The process works by treating sewage sludge, using heat and pressure, and is expected to be in place by 2018.

Nyul added: “Minworth is our biggest sewage works and treats waste water from more than a million homes and businesses across Birmingham and the Black Country and already generates both power for use in the works and also gas for injection into the grid.

“By investing in the THP, we can increase our generation which is good for Severn Trent, for our customers and for the environment.

“The bio-gas we create through this process will both be used to generate electricity and to be treated at our gas to grid plant on site to make it suitable for domestic use before being injected into the grid where it will be used by local homes and businesses.

“The thermal hydrolysis process has an additional benefit as the sludge cake by-product can be classified as ‘enhanced’ status fertiliser and could potentially be used in the production of crops for human consumption. That’s something that we haven’t been able to do ever before.”

Earlier this week, Severn Trent announced it had joined forces with Open Energi to unlock demand flexibility from its equipment to “help build a smarter energy system in the UK”.