This week The Prince of Wales opened the country’s first full-scale Anaerobic Digester and Biomethane-to-Grid Plant which will provide renewable gas direct to the local community in Poundbury. At maximum capacity the plant will provide enough renewable gas for 56,000 new-build homes in the summer and 4,000 in the winter and is the first plant in the UK to inject renewable gas directly into the local distribution network on a full-scale basis.
The plant has already been generating renewable electricity since April, and over the course of a year will export enough electricity for approximately 500 homes.
The Anaerobic Digester is owned and run by JV Energen, a joint venture between local farmers and the Duchy of Cornwall set up to provide a renewable energy solution for the Duchy’s development at Poundbury. Scotia Gas Networks, which runs Southern Gas Networks – responsible for the local gas distribution network – was contracted by J V Energen to clean up the biogas produced by the AD and inject the resulting biomethane directly into the gas network.
JV Energen has selected DMT Environmental Technology’s new Carborex® MS system (http://www.dirkse-milieutechniek.com/dmt/do/index), distributed in the UK by Heat and Power Services Ltd, which uses highly selective membranes in a multistage configuration to provide a simple, low-cost yet robust method of biogas upgrade. “We were convinced that DMT’s new membrane technology would be simpler, cheaper to run and more flexible than previous pressurised water scrubbing systems and hope it will assist us greatly in our efforts to be the first commercial gas upgrade AD plant in the UK,” said Nick Finding of JV Energen.
The Prince of Wales, as Duke of Cornwall, has taken a keen interest in the development of the plant and has been consulted at every stage of the project. The Prince has visited the site throughout its development and on Wednesday November 21st has officially open the plant and heralded a milestone in the renewable energy sector in the UK.
Anaerobic Digestion is a natural process where, in the absence of oxygen, organic material is broken down by micro-organisms to produce biogas which is rich in methane. The Anaerobic Digester at Rainbarrow Farm, Poundbury, will produce this biogas from approximately 41,000 tonnes of maize, grass silage and food waste each year. This fuel will be sourced from local farms and businesses, including Dorset Cereals and the House of Dorchester Chocolate Factory, both based in Poundbury, and Express Potatoes from Weymouth.
An additional benefit of Anaerobic Digestion is that it produces a bi-product known as digestate which can be used as organic fertiliser on arable crops. Digestate retains all the nutrients (nitrogen, phosphorus, and potassium) for fertilising local farmland, and acts as a good soil conditioner.
As well as providing an environmentally friendly waste disposal option and reducing levels of waste being sent to landfill, the plant produces a net carbon saving of around 4,435 tonnes of CO2 equivalent emissions a year.
Simon Conibear, Dorchester Estate Director for the Duchy of Cornwall, said: “This project is a major milestone for Poundbury, Dorchester and the Duchy of Cornwall and for the UK renewable energy industry. It is the result of exemplary collaboration with local farmers and producers of waste, and it will provide a substantial amount of renewable electricity and gas to houses and businesses on the development and further afield.”
Scotia Gas Networks Chief Executive Officer John Morea said: “Greening the gas, by connecting distributed sources of renewable gas to our network as we are in Poundbury, is at the heart of our long-term vision of an enduring and sustainable gas network. It’s a key part of our strategy, and also central to decarbonising the UK’s heat supplies.”
Local farmer and member of JV Energen, Nick Finding, said: “Growing maize for the Anaerobic Digestion plant means we can produce much more energy per acre and we no longer have to send crops abroad to convert into biodiesel. Growing energy crops is an important additional income stream for local farmers like me.”
Fellow Dorset farmer Howard Mason said: “We know the digestate is full of nutrients, and we’re excited to learn how it improves our soils and increases the yields from land producing food.”
Rainbarrow Farm sits on Duchy of Cornwall land just outside Poundbury, the urban extension to the Dorset county town of Dorchester which is built to The Prince of Wales’s architectural principles. Poundbury is known internationally as a pioneering example of urban development and is an example of a sustainable community designed to put the needs of people before cars. Poundbury was created by His Royal Highness in 1994 and mixes high-density social and private housing with work and leisure facilities. Poundbury is expected to be fully completed by 2025 when it will house approximately 5,000 people and provide 2,000 jobs in the factories, offices and general facilities across the site. It is already home to 2,000 people as well as providing employment for some 1,600 people and a home to 140 businesses.
The Duchy of Cornwall started looking at sustainable energy solutions for Poundbury in 2008 and work began in June 2011 on the Anaerobic Digester. The project was undertaken in two phases. Phase one was the development of the Digester to generate electricity with technology supplied by German company Agraferm, which has built around 50 AD plants across Europe. This phase of the plant was completed in February 2012 and electrical generation began at the end of March. Phase Two involved working closely with Scotia Gas Networks for the clean-up and treatment of the raw biogas to produce biomethane followed by the injection of this gas into the local network.
The construction and operation of the plant has and will continue to support local businesses including groundwork operators, builders, electricians, pump specialists, fencing contractors, engineering companies and suppliers of seeds and feedstock coverings.
The entire project can be seen here: http://www.jvenergen.co.uk/page25/page25.html
Written by Constantin Tudose, Area Manager Romania for DMT Environmental Technology
Photo source: http://ecofriend.com/wp-content/uploads/2012/07/organic_waste_cznnz.jpg