A CO 2 -evaluation is made for landfill and Waste-to-Energy (WtE) concepts. Different concepts are identified and compared for their performance on energy and materials recovery. Performance indicators for WtE are compared; like energy efficiency, EXergy efficiency, the R1-D10 formula from the EU Waste Framework directive, and CO 2 -emission and avoidance. It is shown that, due to the biomass content and the avoidance effect due to the recovery of energy and materials, conventional WtE has a near zero CO 2 -emission per ton of waste. Optimised WtE can have a significant negative overall emission of 200–300 kgCO 2 /ton of waste. This means an absolute net avoidance of CO 2 by WtE. The reduction relative to land filling is as much as 500–1200 kgCO 2 /ton of waste. The potential for optimisation of the energy recovery as well as the material recovery of the WtE infrastructure is demonstrated. If WtE is evaluated as a power plant, an optimised plant can have an emission of only 0,336 kgCO 2 /kWh, lower than a gas fired electrical power plant, and this absolute figure does not include the avoided landfill emissions. With CHP this can be reduced even further. The actual potential of electricity production from WtE for the EU-15 is calculated to be over 7,5% of total electricity production. Additionally heat and the metal recoveries could be doubled.

Municipal solid waste (MSW) management is internationally recognized for its potential to be both a source and mitigation technology for greenhouse gas (GHG) emissions. Historically, GHG emission estimates have relied upon quantitative knowledge of various MSW components and their carbon contents, information normally presented in waste characterization studies. Aside from errors associated with such studies, existing data do not reflect changes over time or from location to location and are therefore limited in their utility for estimating GHG emissions and mitigation due to proposed projects. This paper presents an alternative approach to estimate GHG emissions and mitigation using the concept of a carbon balance, where key carbon quantities are determined from operational measurements at modern municipal waste combustors (MWCs).

The EPA has developed the Waste Reduction Model (WARM) to help solid waste managers estimate greenhouse gas (GHG) emission reductions from several different waste management practices. This model is useful for high level analysis but breaks down when applied to specific local systems. This paper will discuss new work currently being done by HDR to provide more reliable analysis of local conditions. This capability is of growing importance given the emergence of national carbon regulations which will require solid waste managers to develop greenhouse gas reduction strategies for their local systems.

The SWANA Applied Research Foundation’s (ARF) Waste-to-Energy (WTE) Group identified the issue of the waste-to-energy’s ranking in the solid waste management hierarchy as one of high importance to the group.

In December 2007 the United Nations Framework Convention on Climate Change (UNFCCC) took place in Bali. It was based on the IPCC report no. 4 presented in Barcelona on November 2007. The messages are briefly: • Warming of the climate system is unequivocal; • Global greenhouse gas (GHG) emissions due to human activities have grown since pre-industrial times; • Continued GHG emissions at or above current rates would cause further warming and induce many changes in the global climate system during the 21 st century that would very likely be larger than those observed during the 20 th century; • Key mitigation technologies in the waste sector: Landfill Gas (LFG) methane recovery; waste incineration with energy recovery; composting of organic waste; controlled waste water treatment; recycling and waste minimisation; biocovers and biofilters to optimise methane oxidation. The above by the IPCC proposed mitigation technologies for the waste sector can be categorized regarding specific waste treatment scenarios and their efficiency expressed in kg CO 2 equivalent emitted per ton of waste. • Landfill w/o LFG recovery 1850 kg CO 2 -eq; • Landfill with LFG recovery 250–775 kg CO 2 -eq; • Energy-from-Waste plant −1000..−100 kg CO 2 -eq. With a population of little over 300 million people and a per capita municipal waste generation rate of 760 kg/person.year, the total waste generated in the USA is about 230 million Mg/year (OECD). With the treatment scenarios discussed above, the following can be stated: • If all wastes were landfilled waste disposal would correspond to 425 million tons of CO 2 equivalents. • If all wastes were incinerated in Energy-from-Waste (EfW) plants, the emissions could be reduced by about 500 million tons of CO 2 equivalents (about 9% of today’s US CO 2 output) and make the waste management sector a GHG emissions sink. • The total electricity generated from EfW plants could be as high as 15,000 MW replacing about 50 standard 300 MW power plant units. To an average US 4 person household about 3 t/year of municipal solid wastes can be allocated, corresponding to an annual difference between landfilling without LFG recovery and EfW treatment of about 6.9 Mg CO 2 -eq /year. If this household wanted to achieve the same reduction of CO 2 equivalent emissions by other means than having these wastes burnt in a modern EfW plant, they have the following options: • Remove one automobile from use (EPA: 6.0 Mg CO 2 -eq /year); • Cut household electricity consumption by 80% (EIA: 7.8 Mg CO 2 -eq /year). The European parliament commission has proposed to reduce CO 2 emissions in Europe to 20–30% below 1990 levels. In comparison with Europe, annual GHG emissions (CO 2 -eq/person year) in the U.S. today are on a level about double that of the Europe. In order to achieve a similar reduction in the U.S., significant efforts have to be done on all energy fronts. Energy-from-Waste (EfW) is one of them, which at the same time solves a space and pollution problem and does not leave these issues to future generations.

A description is given of the key elements of European Union (EU) policy and EU directives, which may affect the desired switch from landfill to Waste-to-Energy (WTE) and recycling of waste within the 27 EU countries. The most important directive is the one which forces individual member states to reduce the landfill levels for MSW to 35% of the quantity of the base year 1995.