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Rapid economic growth places unique challenges on Ireland
as it seeks to meet its future energy needs as well as its
Kyoto emissions targets.
New research suggests that using willow and miscanthus
as biofuel crops could reduce Ireland's overall carbon emissions,
whilst securing long-term economic benefits.
Food crops, such as corn, are often used as feedstocks for
biofuels such as ethanol. Food shortages and increased food
prices are two of the problems recently attributed to the
diversion of food crops for biofuel production. As a result,
attention has turned to using non-food crops as a source of
biomass for energy production.
Willow and miscanthus (a tall grass similar
to bamboo) are amongst the most promising sources of such
biomass. Both willow and miscanthus are fast-growing
and can be burned to produce heat and steam to power turbines.
The CO2 emissions that result when these
crops are burned are equal to the amount of CO2
that they absorbed from the atmosphere during growth.
The researchers quantified the greenhouse gas (GHG) and economic
consequences for Ireland of using willow and miscanthus
for heat and electricity production. They performed life-cycle
and economic analyses to quantify all GHG and economic impacts
arising from changes in fuel-chains, land-uses and carbon-credit
purchase requirements for compliance with Kyoto and future
GHG emissions targets.
Using these crops as biomass fuels could lead to annual emissions
savings of between 7.7 and 35.2 tonnes of CO2
per hectare of land converted to grow the crops. These savings
were calculated from reduced fossil fuel use and land use
change - after accounting for emissions attributable to growing,
processing and transporting the biomass.
Rapid economic growth has led to substantial increases Ireland's
energy requirements and GHG emissions since 1990. Consequently,
Ireland will have to buy carbon credits to meet its EU targets,
or work to quickly include new sustainable energy sources
within the energy mix. A nominal cost of carbon credits of
€10 per tonne of CO2 was used to
calculate the national economic savings attributable to biomass
CO2 reductions.
The net financial costs or benefits likely to be realised
by farmers and consumers switching to miscanthus and
willow biomass were also calculated. Integrating these
economic impacts for a range of possible land use and fuel
combinations, the authors estimated that annual national economic
benefits could equal €457 to €1,887 per hectare
cultivated. The economic benefits of biomass heating are moderately
dependent on oil and gas costs (an oil price of US$58 per
barrel was assumed).
Meanwhile, the economic benefits of electricity-generation
are highly dependent on the trading price of CO2
under the European Emission Trading Scheme (a value of €20
per tonne was assumed). At current CO2
prices, co-firing biomass with coal to generate electricity
is more expensive than using coal alone. However, co-firing
miscanthus with peat to generate electricity and using
willow woodchip instead of oil, gas and electric heating,
could result in both economic and GHG benefits.
The Irish government began offering grants to farmers growing
willow and miscanthus in 2007. To encourage
farmers to grow energy crops, the authors recommend extending
current subsidy schemes and adding modest and well-targeted
financial support and regulation. Grants are also available
to install wood boilers (for burning willow and other wood)
in homes and commercial premises. This could be extended to
include combined heat and power plants.
Using miscanthus and willow could contribute
to Ireland's EU commitments to generate at least 20 percent
of its electricity from renewable sources and emit 20 percent
less GHG, by 2020. The authors conclude that growing these
crops would represent a more efficient land use option than
current liquid biofuel (e.g. ethanol) production from food
crops.
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