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The UK currently has 15 solid waste incinerators, but in order
to deal with the expected increase in municipal solid waste (MSW),
one estimate suggests that we will need 70 more combustion plants.
However, according to the Observer (29/10), statistics derived from
government sources suggest that the resultant emissions of acidic
nitrous oxide gas might be expected to ‘cause at least 350
deaths a year’ for the 25 year life time of the plants- 8,700
deaths in all.
This estimate is, they say, based on a DETR prediction that 50 tonnes
of nitrous oxide emissions would on average lead to one death- and,
despite using newer, cleaner, technology than the current incinerators,
the new incinerators would release 17,000 tonnes. Similar figures
were used by Greenpeace in their campaign against the proposed expansion
of the Edmonton incinerator in London- see Renew 129.
Greenpeace noted that ‘the Department of Health’s Economic
Appraisal of Health Effects of Air Pollution (EAHEAP) have prepared
a cost benefit analysis which calculated ‘Number of deaths not
brought forward’ per tonne of pollution avoided. The figures
are 0.02 deaths a year per tonne of NOx, 0.005 deaths per tonne of
SO2 and 0.002 deaths per tonne of particulates. The figures are quoted
in the DETR’s report: Regulatory and Environmental Impact Assessment
of the proposed Waste Incineration Directive.’
In addition, the Observer noted, there could be deaths due to other
emissions - including heavy metals and dioxins from the combustion
of plastics, a point also made by Greenpeace. The Observer says that
an as yet unpublished US study indicated that 7% of cancers are due
to dioxin exposure, and that around 80% of the dioxin exposure is
from incinerators. In Renew 126, we quoted figures from an earlier
US study which suggested that, in the USA, the incineration of municipal
waste, medical wastes and sewage sludge produced 64% of dioxin emissions.
However, we also noted that the official view in the UK is that incineration
of MSW makes a much smaller contribution than other sources- for example
a 1998 Environment Agency study put the figure for incinerators at
1% of total dioxin intake by human beings, whereas car exhausts contribute
9.5%. Other large emitters include the steel industry and domestic
bonfires. It's also sometimes argued that the combustion of dioxin
sources in incinerators actually reduce the publics exposure to dioxins.
New technologies are also meant to be better at reducing emissions-
especially gasification/pyrolysis .
Even so, it seems increasingly unlikely that concerned local people
will accept incinerators in their areas- for good or ill, after the
BSE disaster, official assurances or risks are simply not believed.
All of which means that the waste management problem is going to get
worse.
Waste Strategy
The UK is supposed to be reducing its reliance on landfill, and increasing
its recycling effort. It certainly has some quite ambitious targets.
As we noted in Renew 126 the governments new waste strategy includes
a two thirds cut in biodegradable waste sent to landfill sites by
2020, and almost a doubling of waste recycling- with 33% being recycled
or composted by 2015. To this end, the Government has just allocated
£50m for curb-side domestic waste collection. However, that won’t
be enough to avoid the need to expand waste combustion.
Many other European countries currently incinerate more waste than
the UK (42% of Denmarks waste is burnt, compared to 9% in the UK),
but they are gradually reducing this in favour of recycling. The enthusiasts
for recycling say it can be expanded well beyond the UK’s target
(we only recycle 9% at present while Denmark recycles 39%) but the
counter view is that this would be expensive. Some hard choices clearly
need to be made. That’s also the case in terms of the use of
waste as an energy source- see our review of ESD’s new report
below, and the Reviews section (Renew 130), p 27-28.
EfW: Energy Recovery
Certainly the issues get even more complicated by the fact that waste
is also a potential energy source- whose recovery offsets the costs
of waste collection and disposal. For example, landfill gas (methane)
can be tapped and is one of the cheapest sources of non-fossil energy.
So of course is the energy released by waste combustion. The NFFO
has supported both in the past- and they were seen as helping the
UK to reach its target of getting 10% of its electricity from renewable
sources by 2010.
However, waste combustion has not been included in the list of renewable
sources in the European Unions draft Renewable Directive (see EU report
later)- and the DTI have decided not to include waste combustion as
a eligible source for meeting the Renewable Obligation. Landfill gas
is however included. Since we have landfill sites, it certainly makes
sense to capture this powerful greenhouse gas rather than letting
it escape. The downside of course is the unsightly and unpleasant
expanses of landfilling and the leakage of often toxic materials from
sites. Some of these problems could be avoiding by better site management
and design, and there may even be ways to get biological processes
established within the decaying waste which can trap and neutralise
some of the leachates- as John Todd argued at the recent Schumacher
Lectures in Bristol (see Renew 129).
Even so, the long term solution must surely be to reduce the amount
of post consumer wastes we produce- for example by reducing the amount
of packaging of consumer products. Just getting consumers to bring
their wastes back to be landfilled, burnt or even recycled, is not
enough.
Keep Burning?
Some argue that pyrolysis or full gassification will be ‘cleaner’
than straight combustion, but it’s not clear if that also means
that dioxin production would be lower. If you really want to burn
something then it looks like energy crops are a much better bet than
waste. British Biogen notes that ‘SRC is not likely to be a major
source of toxic organic substances such as PAHs, dioxins and furans,
which are produced as a result of many combustion processes. Controlled
burning of SRC and use of appropriate pollution abatement equipment
will keep these to a minimum’. On nitrous oxides, it adds ‘wood
has a small inherent nitrogen content, typically 0.1% by weight for
willow SRC, compared with coal which is typically 1%: so using SRC
is likely to result in lower emissions’.
See http://www.britishbiogen.co.uk/gpg/srcgpg/srcgpgenrgyprod.html
ESD on Energy from Waste - Burning Money?
ESD, the Energy for Sustainable Development consultancy, has
produced a report for Greenpeace which looks at the various subsidies
for energy from waste incineration (EfW) projects. It calculates that
the 160MW of electricity generating EfW capacity supported by the
Non Fossil Fuel Obligation (NFFO) and Scottish Renewable Order (SRO)
has received around £233m between 1990-1999, or around 34% of the
£683m allocated to date to NFFO/SRO projects. If this money had been
made available to offshore wind projects instead, and assuming that
these were also supported by capital grants (as has now been proposed
in the DTI consultation on the Renewable Obligation), so as to support
contracts at 5.5p/kWh then, ESD argues, some 154MW of capacity could
have been developed. ESD assume that the 3p/kWh buy out price proposed
by the DTI is accepted and runs for 15 years and that in practice
capital grants only cover 20% of the cost on average, as opposed to
the 40% suggested by the DTI for initial projects.
What about the future? ESD report that, while all four of the EfW
projects awarded contracts under NFFO-1 have gone ahead, only 2 out
of the 10 supported by NFFO-2 have proceeded and only 4 out of the
20 in NFFO-3 have been commissioned. And, so far, no EfW projects
under NFFO-4 or 5 have gone ahead. In part this poor success rate
has been due to local opposition and planning objections. The implication
is that abandoning the new projects would not be a major loss.
ESD say that, from 2000 onwards, when and if they did go ahead, the
new EfW projects, plus existing ones, are likely to receive around
£187m as a result of existing NFFO/SRO contracts, since these contracts
are to be honoured under the transitional arrangement proposed for
the switch over to the Renewables Obligation. If, instead, these contracts
were revoked, and the money was allocated to offshore wind, ESD say
that around 123MW of capacity could be developed- again assuming 5.5p/kWh
contracts over 15 years with capital grants.
ESD also notes that if EFW projects had been left as eligible for
inclusion the Renewable Obligation, then that would have given the
industry a major windfall. Based on the 3p/kWh buy out price, they
could have obtained around £308m by 2010. You can see why the DTI
decided to exclude EfW- arguing that it is now able to operate without
support.
ESD say that, if that money was spent on offshore wind, it could
help to develop some 283 MW of capacity, assuming once again a 5.5p/kWh
contracts over 15 years. Since EfW has been excluded from the RO,
in principle this money is still available. So if we add all the above,
and assume that support for EfW is abandoned, then there would be
£728m available which could support 670 MW of offshore wind by 2010.
See ‘Going to Waste’ ESD/Greenpeace, Oct 2000
MBM Power Doubts
The waste combustion debate took on a new turn with concerns also
emerging over the combustion of ‘meat and bone meal’
(MBM). As we reported in Renew 120, MBW is a powder produced by rendering
down the carcasses of the cows slaughtered under the governments ruling
which requires that all cows are destroyed after 30 months to eliminate
BSE- mad cow disease- from the UK cow herds. Animals which exhibited
signs of BSE are incinerated separately. The rest, the presumably
mostly healthy animals, are converted in to MBM, which is then burnt
as a fuel.
Fibrogen has a plant at Glanford in North Lincolnshire now used for
this purpose- it was initially designed for burning chicken litter.
MBM is actually a better fuel, with less emissions resulting. The
resultant ash is currently being sent to a landfill site at Winterton
in N. Lincolnshire. But, given that there may be some cows with BSE
feeding into the MBM (the MAFF estimate is 1%), there have been concerns
about whether the combustion process would effectively sterilise all
the infected material. The official view has been that there was no
risk.
However, according to the Observer (29/10) recently ‘tests
carried out by the Environment Agency officials on ash from one incinerator
have found potentially lethal proteins in the residue.’
It reported that the agency has demanded that Fibrogen ‘identifies
measures to improve the combustion of the material’ and
‘design and install’ new equipment.
Fibrogen sells the electricity generated from its MBM operation-
and that provides some of the power used by Yorkshire Electricity
for part of its green tariff scheme- subscribers were informed about
the use of this source when the company first took it on. Evidently
most were happy with it. After all, whatever happens, the MBM will
have to be burnt (there is evidently 400,00 tonnes of carcasses still
in store awaiting incineration) and it’s surely better to get
energy from the MBM rather than just burning it without energy recovery.
At least then something good would have come from the BSE disaster.
But if infected material is escaping then not many people will see
this as a green source.
As it turns out however, it’s far from clear whether the Observer
article actually got its facts right. It seems that Fibrogen have
been asked to improve there ash handling process, but this had nothing
to do with safety. Yorkshire Electricity commented (29/10/00) ‘The
article in the Observer is misleading when it refers to "infected
ash" and "potentially lethal proteins" - because MBM
has come from BSE free cattle, the ash is not infected and any protein
traces found in the ash are those of healthy cattle.
As an additional safety measure, the MBM incinerated by Fibrogen
does not contain any traces of spinal cord (the part of the cattle
that could be infected).’
It added ‘Fibrogen have a number of very strict safety procedures
in place to ensure that the ash is transported and disposed of in
a safe manner. When the ash is transported to and from the plant,
it is in sealed, airtight containers. It is then incinerated at 1200
degrees centigrade. The ash that remains is then transported, in sealed
containers, to the landfill site where it is put into an airtight
silo and covered with water to prevent any spread. It is then put
into the landfill site and immediately covered with other material.’
They also noted that ‘Fibrogen regularly send samples of
the ash for testing and those from the chimney beat the standards
for emissions set by the environment agency. Fibrogen are currently
looking at improving the standards in relation to the ash at the bottom
of the grate, this is in accordance with new standards set by the
European Union’.
Finally, it concluded, ‘any risk associated
with the process of incinerating MBM at Glanford is less than one
in 100 billion’.
Pretty long odds then by any standards. Even so, what matters is
the perception of risks, and for many people it seems, statistical
estimates are less convincing than what looks like real and present
dangers. For good or ill then, the MBM issue goes to show yet again
just how unpopular combustion is as a way of dealing with wastes of
whatever kind. Maybe the technology can be improved. Certainly it
must be if we are to continue with waste combustion. But, in an very
competitive energy market, there is always the fear that, despite
regulatory controls, corners will be cut, and errors made. In which
case, given the post -BSE sensitivity of the public to health risks,
the prospects for waste combustion of any type look grim.
The implications for waste strategy are clear, and might be positive
if emphasis is placed instead on source reduction and recycling. But
let's hope that the abandonment of municipal waste combustion and
the doubts about MBM does not also undermine the UK’s green power
programme.
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