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Life cycle sustainability assessment in the energy sector 137

3.1 Large-scale biomass combustion
This case study is based on Stamford and Azapagic (2012, 2014). It is set
within the context of national energy policy in the United Kingdom,
although it is largely applicable to other countries including those of the
EU. It considers 12 techno-economic, 10 environmental, and 14 social indi-
cators to assess the first attempts at large-scale biomass-fired electricity gen-
eration in UK power plants.

3.1.1 Context
In recent years, increasingly stringent legislation in Europe has placed tight-
ening emissions limits on large combustion plants. These measures have par-
ticularly affected coal-fired power generation due to its high emission values
for CO 2 and local pollutants. Examples include the Large Combustion Plant
Directive (European Commission, 2001) and its successor, the Industrial
Emissions Directive (2012), both of which limit the permissible emission
of particulate matter (PM), SO 2 ,NO x , and CO. When combined with
other measures such as carbon emissions trading schemes and taxes, this
has led to the early closure of many coal plants and, in some cases, the con-
version of those plants to partial or 100% biomass combustion.
Examples in the United Kingdom include RWE npower’s Tilbury plant
(750MW), which converted to 100% wood pellets in 2011 (and subse-
quently closed in 2013), followed by E.On’s Ironbridge (600MW) in
2013. At the time of writing, Drax (4 GW) has also completed the conver-
sion of two-thirds of its capacity to biomass and has proposed full conversion
in the future (Selby Times, 2012), as has Eggborough (1.96GW)
(Webb, 2012).
These major, large-scale biomass projects are almost invariably reliant on
wood pellets imported from North America. For example, during its oper-
ation, Tilbury power station imported around 60% of its pellets from British
Columbia (Canada) and 30% from Georgia (United States), the latter using
RWE’s own dedicated wood pellet production facility (Staves, 2011). Drax
also owns major wood palletization assets in North America. In 2014 Drax
alone consumed 60% of all wood pellet exports from the United States and is
the single largest consumer of wood pellets on the planet (US Energy Infor-
mation Administration, 2015).
Projects like these, with large-scale local pollutant emission and long-
distance fuel transport requirements, prompt questions about their sustain-
ability. Consequently, this section explores these questions based on the