Energy from grass cuttings
We are trialling a new way to use grass cuttings to generate energy and reduce the council’s carbon footprint.
The trial is part of a £4 million project which is funded by the Department of Transport.
In partnership with West Sussex Council, the Greenprint project will investigate ways cuttings could be used to make biogas, biomethane fuel for vehicles and an additive for asphalt road surfacing material called biochar.
Greenprint is part of ADEPT Live Labs 2, a 3-year, UK-wide £30 million programme funded by the Department for Transport and developed by the Association of Directors of Environment, Economy, Planning and Transport (ADEPT) that aims to decarbonise the local highway network.
What we are doing
We will be using new machinery to cut and collect grass from selected green spaces and highway verges we manage, where we would normally leave the cuttings on the ground.
The number of cuts will also be reduced from typically 8-10 times a year to 4-5 times.
The cut grass will be mixed with the household food waste already collected by our waste services and taken to the energy-from-waste plant in Avonmouth. There the mixture gets turned into biogas, biomethane or biochar using a process called anaerobic digestion.
How it helps
Existing arrangements of mowing grass frequently and leaving the short cuttings to lay on the grass can help to return nutrients to the soil.
However this doesn’t encourage other plant species to grow, which would create a more diverse natural environment and a home for more insects and other small creatures.
Leaving green areas to grow longer and removing material after cutting should:
- enable wildflowers, insects and other creatures to thrive
- allow the soil to store more carbon
Innovative use of the cuttings and mowing less frequently will help reduce our carbon footprint and work towards to limiting the impacts of a changing climate.
We hope to start piloting the new approach across selected verges and green spaces in Yate during 2023.
There are more than 600 areas of grass included in the Yate pilot, varying in size and shape. They include:
- the banks of the River Frome
- Greenways Road
- Goose Green Way
- Kennedy Way
- Scott Way
- residential areas between St Briavels Drive and Rodford Way
- other smaller areas of grass around the town
The new approach will be trialled in other areas from 2024.
The project will last 3 years followed by a further 5 years of monitoring the environmental benefits, impact, and costs.
This information as well as feedback from the community will be used to decide whether we adopt the approach permanently. No date has been set for this decision.