Air Quality - Environmental Audit Committee Contents

Memorandum submitted by Calor Gas Ltd (AQ01)


  The UK renewables strategy is over-reliant on a mass switch to biomass combustion. The air quality damage in terms of an increase in particulate emissions has been costed by Government at potentially £557 million as a result of premature death: in 2020—one year alone—up to 1,175,000 life years will be lost. The corresponding impact of increased morbidity (disease) has not yet been measured by Government. The combustion of wood in large quantities will lead to rises in the emissions of most of the other pollutants meant to be addressed by the Air Quality Strategy, and in other dangerous pollutants not targeted by the Strategy. The cost of these emissions in terms of human health and the environment should be known, and thrown into an ultimate judgement of the viability of the policy.


  1.  Our submission concentrates on aspects relating to the air quality problems caused by particulates. Their impact on mortality, morbidity and the environment are fairly well understood, quantified and known to be highly significant.

  2.  There is one significant aspect of the UK renewables strategy that will make the targets on particulates harder to reach—an aspect of policy which deliberately and significantly increases the amount of particulate pollution in the air. The Government's Air Quality Strategy 2007 reads at para 95: "Where practicable and sensible, synergistic policies beneficial to both air quality and climate change will be pursued". We describe below how the air quality strategy and the climate change policy are in conflict.

  3.  The UK renewables strategy aims at a big shift to the generation of heat and electricity by biomass: "We will ramp up the supply and use of biomass for heat, power and transport..." (The UK Renewable Energy Strategy 2009, p16). The renewable heat targets are to be met, "mainly through encouraging switching by industrial, commercial and residential customers located off the gas grid from oil, coal or electrical heating, to biomass or other renewable technologies" (para.4.1.6 of "The UK Renewable Energy Strategy 2008"). The strategy contemplates the target of 38TWh of small scale biomass installations. What does it mean for air quality? And, what does it mean for human health, given that air quality is correlated with levels of cardiovascular disease.

  4.  Some of the problems with biomass are frankly described in the consultation paper, "The UK Renewable Energy Strategy 2008":

    "4.6.14  The potential cumulative effect on air quality of fine particles and nitrogen dioxide emissions from a future large-scale deployment of biomass appliances or plant is not yet well understood...In rural areas the impact on air quality, and public health, is likely to be lower, due to both lower population densities and `background' levels of pollution.

    4.6.15  The results from preliminary analysis undertaken by AEA Energy and Environment on behalf of DEFRA indicates that if high levels of solid combustible biomass were used in dense urban areas, where heat demand is highest, the impact on air quality would be likely to be very significant. Stringent emission controls on individual plant would mitigate this effect...".

    "4.6.17  There is currently no clear advice about the locations, types and sizes of boilers that would not cause air quality issues, and there is currently no agreed European test procedure.

    4.6.18  In response to these issues we are considering possible measures that will allow the deployment of biomass-fired plant, in both rural and urban areas, at the maximal sustainable rate that does not compromise our objectives on air quality or public health...".

    "4.6.25 Given that equipment deteriorates over time and needs to be operated properly, we may need to update regulations to ensure that installed equipment continues to be run in a way that meets emissions standards...".

  5.  In sum, biomass boilers without stringent controls will cause significant pollution in urban areas. The resulting pollution is being directed to rural areas because of lower existing levels of pollution in the countryside. We do not yet know the effect of particulates and NOx from biomass boilers—and, as the boilers age, they will pollute more.

  6.  Para 5.17 of the Government's "Biomass Strategy" (2007) states that, "Substitution of natural gas with biomass, on the other hand, generally leads to increases in emissions of all major pollutants". LPG has a similar emissions profile to natural gas. So, insofar as the renewables policy and RHIs manipulate a switch from natural gas or LPG—as is the clear intention—increases in all major pollutants are to be expected. We know from an AEA study ("Technical Guidance: Screening Assessment for Biomass Boilers" July 2008) that a typical domestic wood burning boiler of <50kWth would emit over 15kg of large particulates (PM10) and over 15kg of small particulates (PM2.5) per year per household. The paper states: "For modern appliances with well-designed combustion the particles emitted are all thought to be less than 2.5?". This is no comfort. As "The Air Quality Strategy" (2007) states: "Recent reviews by WHO and Committee on the Medical Effects of Air Pollutants (COMEAP) have suggested exposure to a finer fraction of particles (PM2.5, which typically make up around two thirds of PM10 emissions and concentrations) gives a stronger association with the observed ill-health effects". These observed ill-effects include congestive heart failure, heart disease, cerebrovascular problems and asthmatic attacks.

  7.  On 26 March 2009, in a Written Answer (col 695/6W) to Graham Stringer MP, the Government quantified the social (=health costs in terms of increased mortality) costs caused by emissions from biomass plants under various scenarios. For an uptake of 52TWh of biomass the social costs were estimated as £2,803,000,000 and for 38TWh (the Government target) the comparable costs were £557,000,000—these figures were calculated on the basis of existing technology.

  8. Andrew Tyrie MP asked a follow-up question answered on 10 November (col 219W):

    "Mr Tyrie: To ask the Secretary of State for Energy and Climate Change what recent assessment he has made of the effects of the use of biomass boilers installed to meet Renewable Energy Strategy targets on (a) air quality, (b) levels of particulate emissions and (c) levels of (i) morbidity and (ii) mortality.

    Jim Fitzpatrick: (a) The Government have, in support of the development of the Renewable Energy Strategy (RES), carried out modelling of the effect of an increase in the use of biomass for heat and power on the emissions, ambient air concentrations and public health impacts of fine particles (PM2.5), coarser particles (PM) and nitrogen dioxide. The key air quality results of this analysis are given in the Renewable Energy Strategy on page 121.

    (b)  As part of the analysis the increases in the emissions of particulates were estimated over a number of different scenarios. For PM2.5 these were between 0.75 and 9.1 ktonnes from a baseline in 2007 of 82 ktonnes. For PM10, emissions were estimated as being between 1.3 and 9.5 ktonnes from a 2007 baseline of 135 ktonnes.

    (c)  (i)  The impacts on morbidity resulting from the uptake of biomass as a renewable energy source were not assessed.

(ii)  The mortality health impacts of these scenarios were estimated to be between 340,000 and 1,750,000 measured as the number of life years lost in 2020 from the impact on air quality of increased biomass combustion".

  9.  Presumably, then, the social costs of the increase in particulate emission would be higher than £557m because this costing does not include morbidity. This could be significant. The emission of particulates is estimated to advance 8,100 deaths a year (=mortality) in Great Britain and to cause an additional 10,500 respiratory admissions to hospital (=morbidity) ("Quantification of the Effects of Air Pollution on Health in the United Kingdom", DoH, 1998).

  10.  In relation to particulates, then, the renewables strategy as currently conceived is significantly costly in terms of damage to air quality and human health. The precautionary principle would argue for examining whether there may be other ways of meeting the carbon emission reduction targets other than with such a heavy reliance on biomass—especially if, as we would assert, other route maps would be dramatically less costly (the "Impact Assessment" of UK renewables strategy undertaken by Government costs the policy at £56 billion even after taking into account all the climate change benefits).

  11.  The Government's Air Quality Strategy covers the following pollutants: particulates, oxides of nitrogen, ozone, polycyclic aromatic hydrocarbons, ammonia, sulphur dioxide, benzene, 1,3 butadiene, lead and carbon monoxide. Wood smoke contains emissions of all these pollutants except, perhaps, ammonia. We are not aware of any work the Government have undertaken to quantify the emissions of these pollutants which will be caused by the full implementation of the biomass strategy. Once again, the precautionary principle would suggest not proceeding with the policy until we have assessed the likely impact on human health and the environment.

  12.  We would strongly urge the Committee to consult the website—it is the website of the American Clean Air Revival campaign (Calor has no connection with this organization). This website catalogues, in harrowing detail, backed up with overwhelming scientific data, the emissions released by burning wood and the danger they present. The emissions go far beyond those covered by the Air Quality Strategy, and therefore presumably will not trigger any prophylactic measures to counteract them. These include the carcinogens creosote, methyl chloride and dioxins; and radioactive caesium. We will confine ourselves to referencing just two points made by this very informative site: the US study which found that fireplace wood ash contained up to 100 times more radioactive caesium than would be allowed as a discharge from a nuclear plant; and the WHO estimated in 1997 that wood smoke causes 2.7-3 million premature deaths worldwide. We suggest that the full human and environmental risks of a mass move to the large scale combustion of wood should be known before the harvest of damage in terms of death and disease is established ten or twenty years hence.

26 November 2009

previous page contents next page

House of Commons home page Parliament home page House of Lords home page search page enquiries index

© Parliamentary copyright 2010
Prepared 23 March 2010