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140 Biofuels for a More Sustainable Future

Table 5.4 Origins and shipping routes of North American wood pellets analyzed in
this study

Approximate
Origin Destination Route distance (km)
Vancouver, London South along USA West Coast 16,500
British ! through Panama Canal
Columbia, ! direct across Atlantic
Canada Ocean
Nova Scotia, London Direct across Atlantic Ocean 5000
Canada
Savannah, London Direct across Atlantic Ocean 7000
Georgia,
United
States

United Kingdom, the pellets are transported 10km to the power plant by a
Euro 5-compliant lorry.
While wood pellets are predominantly imported to the United King-
dom, miscanthus is more often grown domestically; thus it is assumed that
75% of miscanthus pellet supply is UK sourced. Domestic miscanthus pellets
are transported from the pelletization facility 100km to the power plant by a
Euro 5-compliant lorry.
The remaining 25% of supply is sourced evenly from the United States
and Canada using the same transport arrangements as that of wood pellets.

Power plant operation
Combustion takes place in a large 500MW power plant, the construction of
which is based on coal plants in Ecoinvent (Ecoinvent Centre, 2010). The
efficiency of the plant is 35%, based on the figure of 35.3% achieved by
RWE npower’s Tilbury power plant after conversion to biomass
(Staves, 2011).
The recent average capacity factor of plant-biomass power stations in the
United Kingdom is 47.1% [5 year average, 2007–11 (DECC, 2013)]. There-
fore a capacity factor of 50% is assumed. In the base case, the plant is assumed
to have electrostatic precipitators capturing 99.95% of particulate matter,
low-NO x burners reducing NO x by 25%, and flue gas desulphurization
removing 90% of SO 2 . These pollution controls are based on the technol-
ogies implemented at Drax at the time of its first conversion to biomass
combustion.