Waste flushed down the toilets in homes in Bristol is helping to create enough energy to power the equivalent of more than 5,000 homes each year.

Bristol sewage treatment works in Avonmouth has been generating biogas produced during the treatment process for a number of years to create renewable energy.

But now state-of-the-art facilities are increasing the amount of renewable energy produced.

Such is the success of the initiative, by Wessex Water, it was named the best large renewable energy scheme at the South West green energy awards.

Mohammed Saddiq, of Wessex Water, said: "We are now producing 40 per cent more biogas at Bristol sewage treatment works during the treatment process which in turn is being used to generate electricity to power the whole site. The amount of energy produced equates to the amount that would be used to power more than 5,400 homes a day – which is about the number of households in Avonmouth ward.

"This not only helps to reduce our future operating costs but is better for the environment. The improvements at Avonmouth have reduced our carbon footprint by 12,900 tonnes a year."

The process works like a human body, solids are broken down and then energy is produced. It involves sludge – a by-product from the sewage treatment process – being passed through newly installed acid phase digesters before reaching the energy production stage.

This allows it to stay in the treatment system for longer, increasing the amount of biogas produced.

The approach was praised by sustainable energy agency Regen SW, which awarded Wessex Water the best large renewable energy scheme for breaking new ground in technology which delivers significant carbon savings.

Wessex Water said the technology being used at Bristol Treatment Works was attracting interest locally and from overseas.