Biogas Technology in Europe

In Europe and USA anaerobic digestion was seen as being mainly used for processing sewage. Traditionally the gas generated was used in static engines to power processes on the sewage plant site and even for powering vehicles. In 1990, the Non-Fossil Fuel Obligation scheme in the UK encouraged investment in new engines in sewage plants to generate electricity to sell to the grid. It also inspired the collection of gas from landfill sites to run electric generating units.

More recent interest by the Green Movement in mainland Europe has encouraged the development of plants to process wastes more directly. High rate anaerobic digestion projects, such as DRANCO, Valorga and Kompogas, were developed in the 1990s, but were not seen as economically attractive for widespread investment.

The introduction of financially attractive electricity feed-in tariffs in Germany in 2000 encouraged the development of large tank digesters to process agricultural wastes and energy crops such as forage maize. The tariffs tended to emphasize the use of energy crops in Germany, a policy that suddenly became less attractive when crop prices increased in 2007. Plants using agricultural and domestic wastes were seen as better investments in Denmark and Sweden. Some of these plants provide gas to power public transport.

A German design of plant was built in the UK by Farmatic Biotech Energy at Holsworthy in 1998, but a combination of a lack of government support and regulations caused the operation to go bankrupt twice. The plant is now being run by Andigestion Ltd who seem to be more successful. The main feed is organic commercial wastes.

Greenfinch Ltd has been developing a digester for domestic food waste, which has culminated in a pilot commercial plant in Ludlow in early 2006. After some initial problems, mainly caused by the feeding of the wrong sort of waste materials, the plant is now running very effectively. They have recently joined up with Biogen to offer AD expertise for the UK.  

View of Holsworthy biogas plant

Main tanks at Holsworthy

Greenfinch project in Ludlow

Photo by Michael Chesshire