LAWR

ANAEROBIC DIGESTION 10 Local Authority Waste & Recycling June 2015 Poor access to food waste is limiting AD expansion Rapid expansion in the past 12 months will see anaerobic digestion (AD) provide a significant contribution to the UK's electricity production. But access to food waste in the medium term could put the brakes on further deployment, according to the National Non- Food Crops Centre (NNFCC). Two hundred new plants have entered the development pipeline in the past year, taking the total to over 500, according to NNFCC figures. But only around a quarter of these (46) are expected to rely predominantly on food waste – the rest will be fed with agricultural crops. "Only two million tonnes of the reported 16 million tonnes of food waste generated every year in the UK is currently treated through AD. The issue here isn't availability – it's accessibility," explained the centre's lead consultant for bioenergy and AD Lucy Hopwood. Speaking at Sustainability Live in April, as he launched the second annual AD deployment report, NNFCC senior consultant Michael Goldsworthy said operators are finding it difficult to provide evidence of where the feedstock will come from for the lifetime of new plants. The findings prompted renewed calls for further legislation on source-segregated food waste collections. ReFood commercial director Philip Simpson told LAWR that "[England] can't continue to rely on voluntary decisions by local authorities". Data published by Wrap for 2013/14 showed that 33% of UK local authorities collect food waste separately, whilst 59% offer food waste collections of some kind. In England, 29% offer separate food waste collections, compared to 53% in Scotland and 95% in Wales. Wales and Scotland have already set in motion new regulations to divert food waste from landfill. On 1 April, Northern Ireland joined them – the new Food Waste Regulations (Northern Ireland) 2015 banned the landfilling of separately collected food waste. District councils will also have to provide seperate food waste collections from 2017 (see page 19). In March, the UK government suggested AD operators would need to contribute to collection costs "for them to be viable for local authorities". NNFCC says poor accessibility could stifle the expansion of AD. Energy from food waste in 2015 Capacity grows In the past 12 months the UK anaerobic digestion sector has "continued to thrive", according to bioeconomy consultants at NNFCC. Some 50 new plants have been commissioned, with the total number of operational plants now standing at 185. These are powered by around 5.5m tonnes of organic feedstock, around 2m tonnes of which is food waste. Farming frenzy Many of the UK's AD plants are farm-based, fed with, usually, a mix of agricultural waste and biocrops. In all, some 636,000 tonnes of slurry, 1.2m tonnes of crops and 229,000 tonnes of crop waste are used. However, agricultural wastes remain an untapped resource – less than 1m of the 90m tonnes of slurry and manure generated are being treated through AD. Bright spark The installed capacity currently totals 168MWe, which is enough electricity for 350,000 houses. There has also been an expansion of biomethane injection plants. Indeed, by recycling inedible food waste through AD, the industry claims it could produce 9.3tWh a year by 2025 – that's enough green gas to heat every household in Northern Ireland. Future development Changes to green energy incentive schemes as well as (potentially) a new government, makes this a big year for AD. The coalition manifesto of 2010 committed to promote a "huge increase" in the technology. But accessibility could be an issue in the next five years – especially in England where there are no regulations to encourage food waste collections.

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