GRASS cuttings from roadside verges in Yate are being turned into green energy in a three-year trial.
Grass cut by council tractor-driven mowers is being collected and sent off to a plant at Avonmouth to generate power.
The project, called Greenprint, will investigate new ways the cuttings could be used, including producing biogas, biomethane fuel for vehicles and as an additive for asphalt road surfacing material, called biochar.
It is being run by South Gloucestershire Council and Live Labs 2, a government-funded decarbonisation project, and is aimed at reducing the district’s carbon footprint.
Workers are collecting grass from highway verges and other green spaces, where it is normally left to lie.
The grass is then mixed with the council’s food waste and taken to an energy-from-waste plant. There the mixture will be subject to a process called anaerobic digestion, where it is broken down by microorganisms in an air-free space, to create methane gas.
The council hopes the Greenprint project will also be good for nature.
Grass areas are usually mowed eight to ten times a year, and the cuttings left on the ground.
Under the new scheme, cuts will be reduced to between two and five a year, which the council says will encourage wildflowers, help insects to thrive, and increase the levels of carbon stored in the soil.
The new arrangements started in Yate over the summer, using existing tractor-driven cutters – new machines will arrive later in the year.
The pilot is gradually being rolled out to more than 600 areas of grass in Yate, including the banks of the River Frome and verges in Greenways Road, Goose Green Way, Kennedy Way and Scott Way, as well as residential areas between St Briavels Drive and Rodford Way.
Trial will expand to other areas
It will be expanded to other parts of South Gloucestershire from next year.
The trial will last three years, followed by a further five years of monitoring of the environmental benefits and impacts, and costs. This information, as well as feedback from the community, will be used to decide whether to make the changes permanent.
The council says the cuttings will be transported with existing food waste in Yate before being transported to Avonmouth, so there will be no extra journeys to take it to the digester – but there will be an increase in lorry fuel consumption because of the extra weight. This will be taken into account as the project is reviewed.
A spokesperson said it was known that mixing grass cuttings with food can enhance the production of methane, and the trial aims to establish if using this to turn the waste into a gas that can be used to produce power will have overall green benefits.
The council’s cabinet member for the climate emergency, Dodington ward councillor Louise Harris, said that, if successful, the scheme could be adopted by other councils across the UK.
She said: “This is an exciting, innovative project which is considering new ways of working to help with our climate and nature emergency goals.
“Our green spaces are an important local amenity, but they also play a key part in supporting the nature recovery and how we manage a changing climate.
“For this trial we will be changing the way we manage our grass areas, along highways and in green spaces, to see if we can make a difference supporting ecology and biodiversity.”
Live Labs 2 programme director Giles Perkins said roadside grass areas could be a great green asset, adding: “This first step is an exciting one in considering how we approach local roads as a whole system, from a decarbonisation point of view.”
More information about the project can be found online at www.southglos.gov.uk/greenprint.