Use of Models and Facility-Level Data in Greenhouse Gas Inventories

Use of Models and Facility-Level Data in Greenhouse Gas Inventories
GHG inventory and the EUETS. Many of the source categories reported in the GHG inventory relate to an economic
sector such as cement clinker production or electricity generation. In order to use and compare UK GHG inventory data
with other data sets, it is necessary for those data sets to cover all or practically all of the installations in those economic
sectors.
This condition is met for those economic sectors that are characterised by a small number of large installations e.g.
electricity generation, cement and lime manufacture, crude oil refineries, coke ovens, steelmaking etc. They all included
in the EUETS, although there were temporary opt-outs in the UK for some installations during Phase I (2005 to 2007)
when those installations that were included in UK Climate Change Agreements (CCAs) were excluded from reporting
emissions data under EUETS. The exclusions due to CCAs covered many sites within the cement and lime sectors,
limiting the usefulness of the Phase I EUETS data for comparisons against other estimates for those sectors.
A number of very small electricity generation plant on islands off the UK mainland are too small to be included under the
EUETS and so no data are available for those sites. The fuels consumed at these sites will be trivial compared with the
fuel consumption of the electricity generating sector as a whole so their absence from some data sets is not significant.
Other IPCC source sectors include many small- and medium-sized enterprises that are not subject to IPPC or EUETS.
This means that it is not possible to aggregate data in the EUETS to cover all of those source sectors as defined in the
UK inventory. For example, the GHG inventory source category ‘other industrial combustion’, IPCC sector 1A2f, covers
the emissions from fuel use across all types of combustion equipment from the largest boilers and furnaces down to
space heating systems similar to those used in the domestic sector. It also covers a wide range of industry sectors
including: non-ferrous metals, chemicals, engineering, papermaking, food and drink. The GHG inventory estimates for
this source category therefore cover a very large number of installations reporting to the CITL, but also cover an even
larger number of additional installations that are too small to be included the EUETS. It is not possible to make a
judgement about what proportion of sectoral emissions might be missing from EUETS data sets. Any comparisons of
reported emissions are therefore limited to a quality-checking of de-minimis emissions for the source sector, due to the
incompleteness of the sector coverage under the EUETS.
In the UK, the definition used for combustion installations for ETS purposes currently excludes devices such as furnaces,
driers etc where the heat from the combustion is used in the device to perform some process such as melting, drying etc.
A more detailed description of the sources included by the UK is given in a regulatory impact assessment report
produced by DECC (EU emissions trading scheme (EU ETS) phase II (2008-2012), potential expansion of the scheme.
Full regulatory impact assessment, February 2007) 11 .
1.3.3 Reporting protocol for carbon emissions
Both the GHG inventory and the EUETS contain detailed information on the sources of carbon emissions, allowing a
distinction to be made between carbon emissions from combustion of fossil fuels and carbon emissions from ‘processes’.
EUETS data includes information on the use of biofuels, but no emissions data are included in the CITL data set.
However, comparison of the EUETS and the Environment Agency’s Pollution Inventory (PI) data for the same installation
can help to identify where carbon emissions reported in the PI might include biocarbon.
Emissions reported under the ETS should exclude emissions from biocarbon. If verified final emissions were used
directly from the CITL there should be no risk of including emissions from biocarbon. However, the raw emissions data
taken from the more detailed ETS show instances of companies reporting emissions from biocarbon use – either these
are errors in the data, or more probably they represent emissions of fossil carbon from fuels that are mixtures of biofuels
and fossil fuels. More clarity in the reporting of fuels would help to resolve this issue.
11 In Phase I, a range of interpretations of the definition of “combustion installation”, and therefore the combustion processes
included within the Scheme, were taken by Member States. These were termed narrow, medium and broad referring to the level of
inclusion of activities. In its decisions on Phase I NAPs, the Commission rejected the use of the narrow definition but accepted both
the medium and broader definitions. The UK followed a “medium” approach, defining a combustion installation as a stationary
technical unit that burns fuel for the production of an energy product (which could be electricity, heat or mechanical power). Around
half of all Member States interpreted the term more broadly (e.g. the Dutch and Danish NAPs), including all combustion units,
whether designed specifically for energy production or not. These inconsistent interpretations have led to competitive distortions in
certain sectors. Member States and the Commission have therefore recognised the need for more consistency in Phase II.
http://www.decc.gov.uk/assets/decc/what%20we%20do/global%20climate%20change%20and%20energy/tackling%20climate%20ch
ange/emissions%20trading/eu_ets/publications/ria-expansion.pdf
IPCC Expert Meeting Report 75 TFI