The Kitchen Waste budget

Here’s the answer I received yesterday to a question I submitted to Lewisham Council about kitchen waste:


Please provide a breakdown of the energy produced by the SELCHP divided into energy produced by incineration of kitchen waste and that of other kinds of waste. What share of this energy production belongs to Lewisham Council and what share of this energy is produced by the incineration of waste produced by Lewisham?


The total energy output of SELCP is 220,000 MWh per annum.

Lewisham waste provides approximately 23.8% of this = 52,360 MWh

From SELCHP’s waste analysis approximately 6.9% of the energy comes from putrescible kitchen waste.

Therefore energy recovered from Lewisham kitchen waste is about 3,600 MWh per year (after deduction of a contribution to the total parasitic load of running the plant) or 1.6% of the total energy output.

This isn’t the first post on this blog about this or the fist time I question the Council on the matter of the incinerator, the revenue it provides and the appropriateness of what’s fed to it, read more here and here.

We know that kitchen waste forms about 35% of the incinerated, and now we also know that it only produces 6.9% of the energy (the 35% is the figure we have for both kitchen and garden waste combined, but I think that we can safely assume that the weight of the kitchen waste in this mix represents the overwhelming majority with the garden waste being in comparison almost negligible. So, let’s live with this small approximation in the know that we’re only looking for a ballpark figure here).

Using the figure provided by DirectGov of 14.0p/kWh as the price for bulk purchase of electricity at domestic or small industrial scale in July 2009 we can put a MWh (unit of the answer) at £140 and this means that 52,360 MWh is therefore sold at approximatively £7,330,400.

Of this amount the kitchen waste, that is about 35% of the incinerated, produces only 6.9% of energy – 3,612 MWh (the answer says 3600 after deduction of a contribution to the total parasitic load of running the plant, the difference with this calculation is so marginal that I’m not even going to approximate all calculations for that) –  at £140/MWh this bring in £505,797.

The remaining 65% produces instead 93% of the energy – 48,695 MWh – at £140/MWh this bring in £6,817,300.

This means that 1% of Lewisham waste at the incinerator earns in energy produced:

–  £14k if kitchen waste;

– £104k if non kitchen waste.

For each percentage point of kitchen waste swapped for non-kitchen waste Lewisham Council would make over £90k, and given that there is enormous demand for the use of the incinerator it would be possible to take out the kitchen waste from the mix and allow non-kitchen waste from other boroughs or other clients to be incinerated instead, this would produce an extra profit for Lewisham Council of well over £3m through increased energy production.

The reduction of 35% of Lewisham’s incinerated waste would also bring a saving in gate fee at the SELCHP of  £1,211,268 for Lewisham (see here).
This would be revenue-neutral for the SELCHP (of which LBL is a partner) as the fee would be replaced that for waste from other clients.

It looks to me that there is therefore an untapped budget for composting of well over £4m available year on year to be derived from the removal of kitchen and garden waste from the incinerator (without even counting the savings of fuel for the fleet of bin lorries that would always travel with a load about one third lighter than they currently do).

These savings could be able to fund a labour intensive composting operation that would provide a large number of local jobs to collect and compost kitchen and garden waste in microsites around the Borough.

For quite some time I wondered if those savings would be able to pay for a replacement collection and composting service, I’d now say that yes, they probably do. The figures need reviewing and I welcome opinions on this proposal.

Yesterday I used my opportunity for a supplementary question to try to explain this to the Mayor, I tried my best to be clear but it’s not an easy thing to do in a Council meeting. I had with me a sheet of paper with these calculations and wanted to give it to him, I explained him “look, I found over £4m for composting in your budget”, but he wasn’t having it, no one came to take the paper to bring it to him, so I sat down and I now write it here.


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2 Responses to “The Kitchen Waste budget”

  1. The Kitchen Waste Budget #2 and other considerations megapost « . Says:

    […] . not really a diary « The Kitchen Waste budget […]

  2. Felix Staratschek Says:


    Greatings from Germany! I have made an informationpage about an german recycling- and waste- management- idea for plastics and e- waste in german and english language (kryo- recycling). Pleace spread this infomation to all persons, you know, that many people get knowkedge about this idea and good alternatives to incineration.

    If you and others have some more or new information, pleace send the information to my adress. .

    Here is the link to my informationpage:

    With best Greatings, Felix Staratschek, Freiligrathstr. 2, D- 42477 Radevormwald

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