Anaerobic digestion revisited

Anaerobic digestion revisited

Following Rockfire’s earlier study of food waste, it is heartening to see that Oxford-based Agrivert has been forging ahead with the completion of anaerobic digestion plants in South Wales and North London. [1]   These two plants represent 40% of Agrivert’s total portfolio and were completed at lightning speed in order to obtain maximum benefit from the government feed-in-tariffs before they were phased out for plants producing more than 1MW.  The two facilities were completed in just nine months and will bring Agrivert’s total treatment capacity to a quarter of a million tonnes.  That’s still nearly 500 swimming pools’ of food, using Wrap’s favourite measure.[2]

The Agrivert plant at Bridgend, opened at the start of this month, is the largest anaerobic digestion facility in Wales.  The facility cost £14m to build and will produce power equivalent to the needs of 5,900 homes.[3]   It generates its own renewable heat as well as methane gas for connection to the grid and a digestate that will be used by local farmers as a fertiliser.

With this facility operational, Wales is now recycling 60% of its food waste each year, up from 4% in the year 2000.  The Welsh Government has set a target of 70% for 2025.

Agrivert started life in 1994 as a waste water treatment operator, converting the sludge from sewage into fertiliser.  It remains active in the area of waste water and offers a number of additional services such as in-vessel composting.  In July this year, its West London anaerobic digestion plant won the AD & Bioresources Association award for ‘Best food waste AD plant’ for the second year running.[4]

It is not likely that Agrivert will continue to expand at the frenetic pace of 2016 now that the subsidies have been removed but if DEFRA’s dream of a 5Mt treatment capacity by 2020 stands a chance of being realised, they and others like them will have to keep up the good work.

[1] Agrivert completes two AD plants in ‘record’ time
[2] Waste and Resources Action Programme
[3] The food we waste is now generating electricity and being turned into fertiliser at a new £14m plant
[4] AD Biogas Awards