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

our analysis, as well as those associated with the use and generation of electricity.
These impacts are discussed in the following sub-sections.
63.1.3.1 Electricity
The carbon intensity of an energy source is the quantity of GHG emissions associated
with generating the energy. Where emissions are avoided as a result of generating
energy from waste, assumptions regarding which source of energy is considered to
have been displaced are important in determining the overall GHG benefit associated
with power generation.
Over the period 2005-2007, electricity demand in Ireland increased by 3.1% per
annum on average. With a growing demand for electricity, the marginal source of
generation – that considered most likely to be newly built in the absence of capacity
arising through energy from waste infrastructure – is assumed to be displaced. For
Ireland the marginal source would be CCGT gas plant, representing the trend in terms
of recently commissioned power generation technology in Ireland. 1205 The CO2
emissions associated with generating electricity from natural gas are taken to be
360g/kWh. 1206
Natural gas is a very clean fuel and is thus completely combusted at CCGT plant,
resulting in negligible emissions of particulates and SO2. The principal emissions to
air associated with the generation of electricity using CCGT are therefore NOx and CO.
The European Commission Reference Document for large combustion plant suggests
a range of NOx emissions of 10-130 g/GJ electrical output depending on the size of
the plant and the abatement technique employed. 1207 Measures taken to reduce NOx
emissions are less effective at the higher generation efficiencies. The lower end of the
range reflects measurements taken at a relatively small (100 MWe) facility using SCR
to reduce NOx emissions. We assume NOx emissions of 70 g/GJ electrical output for
electricity generated at a new CCGT plant.
CO emissions are usually lower for CCGT plant in comparison to the NOx emission,
although these also vary depending on the size of the facility. We assume CO
emissions of 45 g/GJ electrical output for electricity generated at a new CCGT plant
based on data obtained from the aforementioned Reference Document.
1205 Sustainable Energy Ireland (2008) Energy in Ireland 1990 – 2007. Available at
http://www.sei.ie/Publications/Statistics_Publications/Energy_in_Ireland/Energy_in_Ireland_1990-
2007.pdf (accessed May 2009)
1206 BERR (2009) Fuel Mix Disclosure Data Table, UK Department for Business Enterprise & Regulatory
Reform. Available at http://www.berr.gov.uk/energy/markets/electricity-markets/fuelmix/page21629.html
(accessed May 2009).
1207 European Commission (2006) Integrated Pollution Prevention and Control: Reference Document
on Best Available Techniques for Large Combustion Plant, July 2006.
985
International Review of Waste Policy: Annexes