During the past 30 years, over 17,500 anaerobic digestion (AD) plants developed across Europe, over 9,000 of which are located in Germany. In Northern Ireland, there are around 60 plants in operation. AD has created a new enterprise for many farmers and an additional market for crops and slurries.

AD is the natural process of the decomposition of organic matter in the complete absence of oxygen. The AD process begins when organic feedstock such as grass, crops, slurries, food, etc are put inside a sealed tank (anaerobic digester) and heated.