Thursday 14 April 2011

From 11am to 2pm

BiogenGreenfinch's Westwood anaerobic digestion plant is located in Rushden, Northamptonshire. Westwood was commissioned in June 2009 and can process 45,000 tonnes of food waste each year. This amount of food waste produces 2MW of renewable electricity, sufficient to power 3,000 homes continually for a year. A nutrient rich biofertiliser is also produced which can be used on 1,750 acres of growing crop; this fertiliser replaces the need for fossil fuel based fertlisers and is spread on Bedfordia Farms land.

The plant processes all manner of packaged and unpackaged food waste from households, food producers, caterers and supermarkets.

The food waste enters a sealed building where it is processed into a porridge like mixture, before being pumped into temperature controlled sealed digester tanks. Naturally occurring bacteria in the digesters feed on the food waste and produce a methane rich biogas that is captured and used as a fuel in a combined heat and power (CHP) unit. Over 90% of the renewable energy produced is exported to the national grid as a valuable source of green electricity. The remaining electricity is used back in the AD process along with a third of the heat produced, thus making the plant self sustaining.