International Review of Waste Management Policy - Department of ...

Table 63-5: Declining Long-Term Discount Rate as Applied to Landfill Emission
Damage Costs
Period Period Period of of
of
years years
years
Discount
Discount
rate rate
rate
990
29/09/09
0-30 30 30 31 31-75 31
75 75 76 76-125 76
125 125 126 126-200 126 126 200 200 201 201-300 201 201 300 300 301+ 301+
301+
3.5% 3.0% 2.5% 2.0% 1.5% 1.0%
63.2.1.2 The Issue of Gas Capture
There is some debate with regard to both the efficiency landfill gas capture and the
proportion of the gas that is used for energy generation. Of these, the gas capture
rate is both the most sensitive and the most contested component.
A previous assessment undertaken by Eunomia used a gas capture rate of 50%, an
approach based upon two studies conducted on behalf of Defra by LQM and
Enviros. 1215 A subsequent study conducted by ERM on behalf of Defra, however,
assumed a 75% capture rate over the 100 year timeframe assessed. 1216 A
subsequent ERM report acknowledged that if one moved the analysis beyond this
(somewhat arbitrary) timeframe, lifetime capture rates might be around 59%. 1217
Documentation supplied with the Golders model indicates that the expert review
group formed as part of that study considered that 85% of the gas would be collected
during the gas utilisation phases, and a lifetime 75% gas capture rate appears to
have been suggested upon that basis. 1218
The wider literature suggests a range of estimates for the efficiency of gas collection
with a distinction being made between instantaneous collection efficiencies and the
proportion of gas that can be captured over the lifetime of the landfill. 1219 Whilst
1215 Eunomia (2006) A Changing Climate for Energy from Waste? Final report to Friends of the Earth,
May 2006; LQM (2003) Methane Emissions from Landfill Sites in the UK, Report for Defra, January
2003; Enviros, University of Birmingham, RPA Ltd., Open University and M. Thurgood (2004) Review of
Environmental and Health Effects of Waste Management: Municipal Solid Waste and Similar Wastes,
Final Report to Defra, March 2004.
1216 ERM (2006) Impact of Energy from Waste and Recycling Policy on UK Greenhouse Gas Emissions,
Final Report for Defra, January 2006.
1217 ERM (2006) Carbon Balances and Energy Impacts of the Management of UK Wastes, Defra R&D
project WRT 237. December 2006
1218 Golder Associates (2005) Report on UK Landfill Methane Emissions: Evaluation and Appraisal of
Waste Policies and Projections to 2050, report for Defra, November 2005
1219 P. Anderson (2005) The Landfill Gas Recovery Hoax, Abstract for 2005 National Green Power
Marketing Conference; USEPA (2004) Direct Emissions from Municipal Solid Waste Landfilling, Climate
Leaders Greenhouse Gas Inventory Protocol – Core Module Guidance, October 2004; K.A. Brown, A.
Smith, S.J Burnley, D.J.V. Campbell, K. King and M.J.T. Milton (1999) Methane Emissions from UK
Landfills, Report for the UK Department of the Environment, Transport and the Regions.