Redstow Renewables Anaerobic Digestion Plant near Swaffham, Norfolk. Photo: Future Biogas
Finding new ways of generating energy is crucial to help reduce our dependency on fossil fuels. Anaerobic Digestion (AD) is a biological process where microorganisms break down organic material without oxygen to produce biogas.
The UK produces 10 million tonnes of food waste each year that can act as a renewable source of organic material for the AD process. Food waste is still dumped in landfill sites where it gives off methane, a potent greenhouse gas, when it rots. This waste can also contain phosphorus and other trace metals that can contaminate water if left unattended.
AD plants are facilities capable of producing biogas consistently at a large industrial scale. They don’t produce any emissions and, as a side product, they can produce a valuable fertiliser for farming which can provide another revenue stream. This product will have lower levels of pathogens as the operating temperature of the process is low, reducing the risk of losing crop yields to diseases. The strengths of AD plants make them one of the best methods of dealing with our food waste whilst producing green energy. However, the technology has a few cons and the most important are costs and scale.
Anaerobic digestion is only profitable on a large scale and to build the anaerobic digesters that house the process is very expensive and requires a lot of available land. The costs involved with obtaining organic material in large quantities and storing it must also be considered. The process is time-consuming and requires daily attention and, to ensure the process is efficient, regular maintenance of the system is necessary.
Future Biogas is a company that specialises in AD and operate 11 crop-based AD plants spread throughout the UK, including 5 plants in Norfolk. The plants use organic materials like maize, whole-crop cereal, chicken manure, grass and beet. The green energy the plants produce powers UK homes, the Centre Parcs at Sherwood Forest, Noble Foods, British Chlorophyll and Holkham Estate. Redstow Renewables is the company’s largest AD plant west of Swaffham operating at 4.5MWe. Future Biogas has recently managed to set up a green energy supply to RAF Marham, 6k west of the plant. You can visit their website to find out more about them www.futurebiogas.com.
Agri-Tech East are hosting an event at Hethel Engineering Centre called ‘We’ve Got the Power; On-Farm Solutions to Energy Demands’ on the 23 May from 1:30 to 5pm to discuss topics like anaerobic digesters and other alternative energy technologies and you can sign up and find out more here www.agritech-east.co.uk.