Wednesday, October 10, 2012
Boris Johnson should prioritise anaerobic digestion in London
05 Oct 2012, Jenny Jones
Questions have to be asked why not a single Anaerobic Digestion (AD) plant is in operation, or currently in construction in London, despite strong backing from both the previous Mayor of London and the current Mayor, whose revised strategy says AD is the optimal treatment method for food waste, after waste reduction.
The emergence of AD in the capital has finally started, with two plants granted planning permission, but this painfully slow progress raises doubts about the effectiveness of the Mayor's Waste and Recycling Board as it enters its second term.
Has it allocated enough resources to advancing this technology, which could end the deplorable practice of sending hundreds of thousands of tonnes of food waste to landfill each year, where it rots producing the potent greenhouse gas methane?
Once operational, these two plants will have a combined capacity to deal with roughly 90,000 tonnes per year of food and green waste. Whilst extremely welcome, they will only be able to deal with one fifth of London's annual 460,000 tonnes of food waste.
According to Mayor of London Boris Johnson, the reasons for AD proposals failing to be realised include project financing, planning, guaranteeing feedstock, and agreeing gate fees.
Another threat that was lurking on the horizon for AD was the Government's proposal to block energy installations smaller than 5MW from the Renewables Obligation Scheme (ROC). Fortunately, the Department of Energy and Climate Change responded to the major concerns raised by the renewable sector and the detrimental impact it was likely to have on the renewables industry and this week announced that ROC's will remain available to new AD projects.
The lack of delivery of AD plants over the past decade, which depends on uncontaminated feedstock, is probably one of the reasons why so few boroughs have to date provided all or most of their residents with food caddies for separate food waste collection schemes. However, landfill tax will rise until at least 2014, when it will be £80 per tonne, putting up London's annual bill for sending municipal waste to landfill from about £265m to roughly £300m.
In the absence of AD capacity, councils with shrinking budgets may just divert food waste from landfill to new 'energy from waste' facilities, circumventing AD, the most beneficial method of dealing with food waste.
But the benefits of AD are numerous. It turns food waste into biogas for generating heat and electricity, or into bio-methane for injection into the national gas grid or conversion into transport fuel, and produces a rich fertilizer for garden and agricultural use.
The benefits don't stop there. Using food waste productively can also create jobs and help exceed composting targets.
Data obtained from WRAP earlier this year showed that nine London councils were not providing separate food waste collection schemes: Barking & Dagenham, Hammersmith & Fulham, Havering, Hillingdon, Kensington & Chelsea, Lewisham, Newham, Redbridge and Wandsworth.
This leaves residents with the choice of either composting food waste in their gardens, if they have one, or putting it into the black waste bag. Although a small proportion of this black bag residual waste may then be segregated, the vast majority is collected by the council and sent to landfill, or incinerated.
In contrast, councils like Bromley, Croydon, Camden and Richmond were providing almost all or nearly all of their households with separate food collection schemes, which they then composted or sent to an AD plant outside London. Some notable recent improvers were Southwark, which rolled out a food collection scheme to around half of their residents, and the City of London, which doubled its food collection scheme to reach all its residents.
The Mayor has stated that his proposals for anaerobic digestion capacity of 260,000 tonnes in London are being progressed, but it is unclear how his target will be achieved, at the rate of progress so far.
I would like to see the Mayor review the resources, and the priority his London Waste and Recycling Board gives to AD, and then draw up measures to help fast track AD and make it the preferred treatment method for large scale food waste.
Unless sufficient AD capacity is delivered, I fear less beneficial waste treatment technologies and facilities will be built in London, and become the council option to ever dwindling and costly landfill, keeping AD small scale and mainly aspiration in mayoral strategies and government press releases.