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Waste to energy for London

by Mel Starrs on November 3, 2009

in Renewables

waste to energy london assemblyLast month saw the issue of the report ‘Where there’s muck, there’s brass‘ (pdf, 34 pages) from the London Assembly.

Waste to energy is a topic which remains on periphery of many building services engineers range of expertise – and yet we are expected to have opinions and knowledge of the technology. Would we be expected to know as much about power stations? Possibly not.

Anyway, the report sets out some useful facts and figures (with a London centric bias, obviously).

There is a Mayoral target for doubling recycling rates to 45% by 2015 and 50% by 2020. The report acknowledges this reduces the potential volume of fuel for waste to energy plants, but emphasises that energy to waste is part of a hierarchy, which begins with the classic reuse, recycle and compost:

Where waste cannot be reused, recycled or composted, value should be recovered in the form of materials and energy.

Costs of landfill are explored, with some useful figures:

The rising costs of waste disposal and incentives to reduce landfill (landfill tax is set to increase by £8 per tonne per year, rising from £48 per tonne in 2010 to £72 in 2013) plus long term increasing energy prices from fossil fuels makes the economic argument of using waste to generate energy even stronger.

Risks, in the form of air quality is covered and cited as a reason why incineration is not considered (plus the fact that it does not qualify as a renewable, and therefore does not benefit from ROC’s, unless in CHP mode).

Four technologies are covered:

  • Non-thermal
    • aerobic and anaerobic digestion
    • mechanical biological treatment
  • Advanced Thermal Treatment
    • gasification
    • pyrolysis

The most interesting section for me was the barriers, 6 of which were identified:

  1. Contracts
  2. Planning
  3. Unproven techniology
  4. Public opposition
  5. Inadequate infrastructure
  6. Grid connectivity

By far the most pressing issue from an engineering point of view is the question of infrastructure. It is something which is coming up, again and again in the zero carbon debate, and with the renewable heat incentive will start to figure more and more. The realisation that buildings are not islands, but part of a larger network (at least on a community scale) needs to be addressed, and quickly.

And if you want to read a more forthright plea in favour of waste to energy, Jackie Sadek (my blogging idol du jour) is on top form, as always, here.

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