When examining the potential of biomass for co-firing in each location it is necessary to consider not only internationally traded biomass fuels but in the first instance the potential of indigenous biomass resources in order to establish the scale of the benefits that might be realized in practice.
Several forecasts have been undertaken in the United Kingdom to date on the quantities of biomass fuels that could be obtained from UK indigenous sources. The Cadent Review of Bioenergy potential 2017 (Review of Bioenergy Potential, 2017) made a critical and independent assessment of earlier forecasts (by Committee on Climate Change referencing work by inter alia Ricardo, and AEA) and produced a range of estimates for potential non-waste solid biomass fuel production potential in the United Kingdom up to the year 2050. A medium-range scenario has been defined in order to illustrate the effects of planting rates, constraints and competing factors, resulting in a considerable prediction for 2050. These are shown in Table 1.
Energy crops are seen to present the largest potential resource amongst biomass fuels internationally, but considerable uncertainty exists as to the rate at which the market can be developed, and critically in the sustainability constraints and cost which together with competition for land use will ultimately pose a limit on their development.
It is important to note the implicit assumption by many jurisdictions which support biomass energy developments that subsidies for energy crops are required to establish supply chains rather than to compensate for the intrinsically higher wholesale cost of biofuels compared with fossil of the order of US$9 per GJ for wood pellets (source: Wood Pellet Association of Canada) c.f. US$3 per GJ for natural gas (Henry). In a similar vein it is often presumed, without logical justification, that grown biomass fuels will be competitive with fossil fuels when demand for oil and gas ultimately outstrips supply.
These considerations point to the observation that in order to establish the widespread use of solid biofuels it may be vitally important to establish an effective global emissions trading scheme to discourage the release of fossil carbon into the atmosphere. The traded price of GHG emissions to bring this about has been predicted by the World Bank to be of the order of US$40 – 80 per tonne of CO2 equivalent by the year 2020 (State and Trends of Carbon Pricing, 2017).
