United Utilities cuts carbon emissions by 11%

United Utilities has reduced its carbon footprint by 11% over the past year, with a recently opened anaerobic digestion (AD) plant taking the water giant's renewable energy production to new heights.

The Warrington-based company, which is the largest listed water firm in the UK, has reduced its carbon emissions by 23% since 2005/06, with an overall aim of reducing emissions by 21% by 2015, off a 2006 baseline.

Part of this reduction will be achieved via United Utilities’ new £100m AD plant in Davyhulme, Greater Manchester. The advanced sludge thermal hydrolysis plant is the largest of its kind in the world; generating biogas from Manchester’s sewage sludge which is used to power turbines on the site, creating clean, green electricity.

“The recent completion of our recycling and energy plant at our Davyhulme wastewater site has contributed to our highest ever renewable energy production in 2013/14,” said the company’s CEO Steve Mogford.

“This represents c17% of our total electricity consumption (up from c13% last year) and has helped us avoid energy purchase costs of around £10m, as well as attracting renewable incentives of around £5m.

“We have plans in place to further increase renewable energy production over the next few years.”

The Environment Agency’s latest ‘eco-friendly table’ ranked United Utilities joint-second out of the UK’s 10 water and sewerage companies in 2012-13.

Sustainable business

Earlier this year, edie reported that United Utilities had been looking at innovative ways to recycle hard-to-handle waste materials as part of its materials re-use drive. The water firm digs a lot of holes during its operations – last year, it recycled 88% of the soil and stones that it removed from the ground. However, some of the residue material is harder to recover and the company has been working with its contractors to find solutions to this challenge.

It has also been working on waste prevention and last year the overall volume of waste generated was 970,000 tonnes – a 15% decrease on the previous year.

Promoting water efficiency is also another priority. In 2012-13 its customers saved 3.13 mega litres of water per day beating United Utilities’ target of 2.51 mega litres per day – the third successive year that its Ofwat-set target has been superseded.

United Utilities’ carbon emissions totalled 524,264 tonnes of CO2 equivalent in 2013 – an increase of 0.4% from the previous year.  The firm says a key factor behind this increase was the wet weather, which required it to purchase more electricity for operational purposes.

The company also saw a decrease in the amount of renewable energy it generated in 2012/13, due to a combination of technical issues, planned maintenance and a loss of output as existing combined heat.

Luke Nicholls

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