Renewable energy from waste
The National Physical Laboratory (NPL) is working with Cranfield University to develop and test a method for calculating the potential renewable energy derived from waste material, which could save time and money for the energy and waste industries.
Around 200 million tonnes of the waste produced in England alone could be converted to energy that has the potential to supply up to 4% of the UK's electricity and water heating needs. There are incentives for UK electricity suppliers to source more of their electricity from renewables and they must also demonstrate the biomass content of mixed fuels. However, current techniques for calculating the renewable content of waste involve inefficient manual sorting or expensive flue gas analysis.
The Technology Strategy Board (TSB), Department for Environment, Food and Rural Affairs (Defra) and Department of Energy and Climate Change (DECC) recently funded work to develop a new process at Cranfield University, which uses an image and microwave analysis tool. When placed above a conveyor belt in a waste treatment facility, this tool is able to accurately determine the composition of a mixed waste material and subsequently calculate how much renewable energy can be produced from each component of the waste.
NPL's role in the project is to develop and test measurements of water content, which is important for calculating the net calorific value, or energy content, of the waste stream. Microwaves are used to make this measurement as they can penetrate deeper down through a volume of waste than optical techniques. The microwave energy is passed through the material and some of it is absorbed. At certain frequencies this absorption is proportional to the number of water molecules, and this makes it possible to obtain the water content by measuring the transmission loss.
NPL will continue to work with Cranfield University to further develop the tool and test it in a range of waste handling facilities.
Find out more about NPL's work in Electromagnetics
For more information, please contact Richard Dudley