Anaerobic digestion offers farmers food for thought

The UK's emerging anaerobic digestion (AD) industry was thrust into the limelight this week after two major new projects that promise to demonstrate the viability of the waste-to-energy technology were unveiled.

First up, energy firm Farmgen broke ground on the first in a wave of anaerobic digestion plants, designed to provide farmers with an additional revenue stream from "energy farming".

The £2.5m project at Carr Farm in Warton, Preston will be the first AD plant built under Farmgen's proposed £30m UK-wide investment programme. Local crops will be used to create biogas that will generate 1MW of electricity, which will then be exported to the national grid.

Farmgen said that it also plans to build a second £2.5m plant in Silloth, Cumbria later this year and is preparing planning applications for sites in Lancashire and Staffordshire.

The coalition government has earmarked the accelerated roll out of AD plants as a key part of its renewable energy strategy and last month launched a consultation designed to assess how new policies could help increase support for the emerging sector.

Under the existing feed-in tariff scheme, farmers or businesses installing AD systems generating up to 500 kilowatt hours (kWh) a year are eligible for payments of 11.5p per kWh, while those installing larger systems producing 500kWh to 5MW receive 9p per kWh.

Industry insiders have warned that the rates are not currently high enough to drive the widespread roll out of AD plants and have been calling on the government to increase in the incentive.

In related news, airport operator BAA announced yesterday that it has signed a deal with food management firm Vertal that will see travellers food and drink waste turned into fertiliser for use on local farms.

The company said that food waste from Heathrow's daily 180,000 passengers will be collected separately and sent to Vertal’s recycling facility in South London where it will be composted within 72 hours.

It added that it hoped the initiative would save carbon emissions equivalent to around half a million air miles.

Vertal founder and managing director Leon Mekitarian said he hoped the deal would encourage other firms with large amounts of food waste to invest in composting technology to reduce their carbon footprint.

"Our accelerated composting technology is significantly more carbon positive than any other process," he said. "And as the market matures and new legislation comes on stream, that's becoming a very important business factor."