Thursday, July 09, 2009

Waste, Recycling and New Technologies

I've just come up for air after a seemingly endless meeting of the Environment Committee. You know it's going to be rough going when there are more expert witnesses (8) than members (7) - anyway, here goes:

This morning we looked at the development of new methods to extract energy from the waste that can't be recycled. One witness suggested that this technology is at the same stage as the computer industry 25 years ago, on the verge of life changing innovations. The Microsoft of waste management waits in the wings.

Anaerobic Digestion

Known as 'AD' to the waste community, this is the most favoured option and it is already used for sewage, with Thames Water operating 60 plants. The idea is to allow bacteria to digest the organic waste element, producing gas that can be used as fuel. Essentially the same process happens in landfill sites but most of the gas escapes into the atmosphere, whereas AD ensures it is captured for the community.

The gas can then be cleaned up and injected into the national grid of gas pipelines. Alternatively the plant can be connected to a local housing estate so the immediate residents get the benefit, but this is expensive and difficult where existing buildings require a retrofit. Local distribution is more viable for new build or for a single large industrial or public sector customer. Another alternative is to use the gas as fuel for a vehicle fleet, usually operated by the public sector.

Friends of the Earth favour AD and campaign in support of the technology but they acknowledge that the need to transport residues away by road creates some problems in the city.

Planning permission for AD seems to be relatively easy to secure, unlike incineration - the Belvedere incinerator took 16 years to approve...

Other Technologies

Including gasification and pyrolysis are as yet unproven. They burn waste gas in an engine to create electricity but the ultimate aim is to use fuel cells - which work like batteries - to generate power. These have the advantage of no moving parts so they are more efficient but current models don't work well with impure gas.

Developing solutions face problems obtaining funding, particularly in the current economic climate. Financial institutions prefer to see at least one pilot plant working, preferably in this country, before risking their money.

Friends of the Earth were less impressed, describing some of the technologies as no better than landfill or incineration.

Large vs Small

Operators prefer larger applications because one big site can achieve economies of scale and can attract the sort of large waste contracts that make investing significant sums a viable prospect. However large sites tend to attract greater public opposition so they take longer to pass through the planning process. In addition, a plant handling more than 50,000 tonnes of waste requires approval by the Mayor, so large applications will face delays and paperwork.

Commercial considerations favour large sites but public opinion and planning law tends towards smaller installations.

Waste Map

All this means that the plan to locate waste disposal sites around London is likely to change, with fewer sites designated. The current map identifies many potential sites particularly in East London. In my own patch, Hainault, Harold Hill and Rainham are identified as suitable locations for such facilities.

With the recession the volume of waste has actually started to fall so less capacity is going to be needed in the short term, however not everywhere is well served. One witness pointed out that Hackney residents seeking to dispose of objects like fluorescent light tubes are instructed to take them to Islington's civic amenity site at Hornsey - it seems unlikely that everyone will take the trouble to embark on such a journey.

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