How Yorkshire Water is turning sewage into electricty at its revamped Leeds site

The organisation has now completed its new treatment and anaerobic digestion facility at its Knostrop Energy & Recycling Facility, which stands just a few miles out of the city centre in the Aire Valley area of the city.

In a series of giant towers, pumps and pipes it is creating more renewable energy, making significant cost savings and is on course to help the the Lower Aire Valley become a hub for green energy and industry.

In the last five years, 3,000 people have worked on turning the water treatment plant, which has been there for a hundred years, into a lead for other water companies to follow, according to a former secretary of state.

Rt Hon Hilary Benn, the MP for Leeds Central said: "The exciting thing about this is that this is the future. Last week in Parliament we passed a change to our law which agreed we need to be net zero by 2050 and this is a wonderful example of how we are going to do that.

"People see something like this and other water companies can do the same. The word spreads and technology gets better, that is why the investment was worth making."

The plant takes waste from all around Leeds which is passed through thickeners and fed into anaerobic digesters, where it is held for 12 days to make methane biogas and digested sludge.

That biogas, in turn, powers two heat and power engines and two boilers to create energy. That sludge is treated with lime before the hardened sludge is recycled to agriculture. The byproduct is pumped into the new treatment plant and the treated product is returned to the sewerage works.

Previously most of the waste was incinerated or sent to landfill.

Statistics

94 per cent of Leeds sewage sludge will be recycled at Knostrop.

The site will process up to 131 tonnes of dry sludge a day, 48,000 tonnes of dry sludge per year.

55 per cent of the energy required to run Knostrop will come from the renewable energy we generate on site - the equivalent of powering 7,600 homes.

3,700 cubic metres of methane can be stored at Knostrop and all of this turned into electricity to power the site.

15 per cent reduction of Knostrop’s carbon emissions will come as a result of this investment - Carbon footprint saving equivalent of 85 flights per year from London to New York.

Richard Flint, the chief executive of Yorkshire Water added: "It is a day of celebration. More important is what this will do in terms of reducing energy and carbon and what it says in terms of the commitment to be carbon neutral by 2030. This plays a huge part in changing the climate and the economy for the future."