Renewable energy to be produced with food waste

Edinburgh and Midlothian Councils’ proposal for a contractor to deliver anaerobic digestion (AD) facilities is being prepared to meet the requirements of Scotland's Zero Waste Plan.

The Zero Waste Plan, which is expected to come into effect in 2015, has been implemented to impose bans on source-segregated food waste and recyclables. The Councils of Edinburgh and Midlothian insist that anaerobic treatment will meet these prerequisites and hope that the AD contract will be awarded in 2012.

At present, most food waste in Edinburgh and Midlothian is sent to landfill. This unsustainable practice wastes resources and contributes to the production of methane, a powerful greenhouse gas.

AD is the process where plant and animal material is converted into biogas, in the absence of air, by micro-organisms. The biogas can then be combusted to produce electricity and/or heat.

The contractor who provides AD facilities will treat 20,000 tonnes of food waste collected by the Councils. At the facilities, the waste will converted into biogas to produce renewable energy.

This development is a significant step towards a sustainable future in the UK. Kenny Boag, SEPA head of Waste Policy, said:

"There is significant and growing interest in the use of anaerobic digestion technology in Scotland. It is a technology that can help maximise the recovery of value and resource from source segregated biodegradable wastes, principally through the recovery of biogas and high quality soil improvers."

With rising demand for bioenergy and AD, Scotland will be at the forefront of renewable energy. Edinburgh and Midlothian Councils are set to commence a separate procurement process for mixed waste treatment facilities later in the year. This will be in time for the proposed ban on the disposal of biodegradable waste to landfill in 2017.

AD recently came under some scrutiny with critics citing high costs and the contamination of water as disadvantages. David Reay, lecturer in Carbon Management at the University of Edinburgh disagrees with the claims, saying: “There should be no water contamination issues with well-run AD plants - they are subject to stringent environmental pollution regulations.

“With efficiency of scale, AD is a financially viable option.”

The Millerhill site has been purchased by Midlothian and Edinburgh Councils. Moreover, an application for planning permission to build a 30,000 tonne per year AD facility will be submitted by spring 2011.