Severn Barrage will pay back carbon in less than six months, says study
The payback period of carbon costs incurred by the production and transport of materials and construction work for the Severn Barrage would be less than six months, according to a recent study published by the Chartered Institute of Water and Environment Managers.
The barrage would be formed of reinforced concrete caissons constructed on shore and towed to the site, along with over 200 large water turbines and electrical generators and 166 sluice gates. This would incur a large carbon cost. However, the Ciwem study noted that once in place it can fill up to 5 per cent of the UK's electricity needs.
In just over four and a half months the barrage can be expected to have paid back the carbon costs incurred from the sourcing of materials, manufacture of components and their transportation to the barrage site. When including the on-site works used to construct the barrage, this increases the payback period to five and a half months, Ciwem said.
The authors also point out that there is little carbon cost incurred during plant operation, and that although the barrage will take nine years to build, it can begin electricity generation while still part constructed.