Food waste (not including my fish pie) collected by the majority of the commercial waste management companies in Oxfordshire and Berkshire goes to AD (Anaerobic Digestion) in: -
Wallingford (Design Power Output 2.4 MWe) - (Severn Trent Green Power)
Cassington (Design Power Output 2.1 MWe) - (Severn Trent Green Power)
Basingstoke (Design Power Output - 1.2 MWe) - (Herriard Bio Power).
The food is ‘digested’ for an average of 85 days in large concrete stomachs (Severn Trent example) with the methane being withdrawn throughout the process and fed into generators which covert it into electricity which is fed onto the National Grid (Methane is generated by the decomposition of organic matter). 1 tonne of food generates approx. 390 kWh of electricity.
(Methane produces 21 times as much warming as CO2 and accounts for 20% of the 'enhanced greenhouse effect'. Food waste discarded into landfill allows the methane to be liberated into the atmosphere.)
The ‘digestate’ (the remaining liquid phase) is rich in N,P,K, (nitrogen, phosphorus, potassium) and has Soil Association certification for land injection on farmland as a soil improver within seven miles of the AD facility thus keeping vehicle emissions to an absolute minimum. Nitrogen added to soil in a liquid state is far quicker absorbed and therefore available for use sooner than when supplied in a solid (fertilizer).
Anaerobic digestion does not accept compostable packaging or cutlery due to the material’s inability to biodegrade over the optimal AD digester retention time. As part of the scope under the PAS 110 standard/specification for digestate from AD facilities, no individual man-made element within the final digestate may be larger than 2mm.
So where are all of these wonderful treatment plants - link
Picture - a bowl of the best fish pie created on planet Earth (by me) more like this (fish pie) - link
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