Fuel of the future

United Utilities has teamed up with National Grid to convert a by-product of the wastewater treatment process into gas for injection into the local gas pipeline network.

The £4.3m initiative, which is expected to be operational by early 2011, will be based at the Davyhulme wastewater plant in Manchester and has been given funding by Defra through its Waste & Resources Action Programme (WRAP).

Caroline Ashton, biofuels manager at United Utilities, said: ‘The team is thrilled to have won this funding, which will give the project a huge boost. It has been in development for some time, but now we can put our plans into action and the people of Manchester will soon be using “poo power” to heat their homes.’

The plans involve installing the upgrade equipment, a gas compression and fuelling station and a pipeline to link into the local gas distribution network. In addition, United Utilities intends to use the converted gas to fuel a fleet of sludge tankers.

Janine Freeman, head of National Grid’s Sustainable Gas Group, said: ‘Biomethane is a fuel for the future. Renewable electricity from sources such as wind power is already available, but this is the first time we will be able to supply renewable gas to consumers. This pilot is an important step in helping deliver a low-carbon energy future.

‘Not only are we reusing a waste product, but biomethane is a renewable fuel, so we are helping to meet the country’s target of 15 per cent of all our energy coming from renewable sources by 2020.

‘This pilot project should supply gas to about 500 homes and the overall potential of biomethane from a plant like Davyhulme would be to supply a small town of about 5,000 homes.’

A United Utilities sludge tanker has already been converted to run on diesel and compressed natural gas, demonstrating that a dual-fuel system does not affect the engine performance of such heavy vehicles.

Ashton added: ‘When we have the kit in place to utilise the gas produced on site, we should be able to save hundreds of thousands of pounds a year in fuel costs with the 24 tankers we aim to convert initially.’

According to the National Grid, there will be no fundamental technical difficulties to injecting biomethane into the gas distribution network with a number of plants in Europe demonstrating its possibility.

Dr Richard Swannell, director of Retail and Organics at WRAP, said: ‘Working with National Grid, the project aims to be the first in the UK to process and inject biomethane into the gas grid on a commercial scale. By using biomethane as a fuel for sludge tankers it could also help our country make more widespread use of renewable energy.’