[Press release] New ICCT study: Reassessing global potential for energy from biomass
For immediate release: 25 March 2014
Many climate change mitigation strategies rely on projections of strong growth in biomass energy. But a new study by the International Council on Clean Transportation casts doubt on much of the research behind those projections, and questions whether the ambitious goals for bioenergy use required by those strategies can be sustainably achieved.
U.S. federal government policy supports transport biofuels through the Renewable Fuel Standard. The European Union has set a target of 20% of all energy in the region to be renewable in 2020 and 50% by 2050, with much of the shift being met with co-firing biomass in coal plants and transport biofuel consumption. “These targets are important for guiding decarbonization in the transport and renewable energy sectors,” said Stephanie Searle, the paper’s lead author. “But a common problem with much of the associated long-term government and research modeling is that it assumes practically unlimited potential for biofuel production. But biofuel potential isn’t really a limitless panacea to be accepted simply by assumption.” The question the ICCT researchers sought to answer in their paper, published in the journal GCB Bioenergy, was whether the displacement of fossil fuels with biofuel and biopower can be scaled up as dramatically in coming decades as these models estimate.
Surveys of studies estimating future bioenergy potential done by the International Energy Agency (IEA) and the Intergovernmental Panel on Climate Change (IPCC) revealed a wide range of estimates of the amount of biomass that could be available from energy crops, wastes, and residues without impacting food production. The IEA and IPCC reports indicate that the potential for future bioenergy production in the 2050 timeframe is equivalent to 500–1500 exajoules per year, which ranges from about ten to twenty-five times the current total bioenergy usage worldwide, and up to double the expected global energy consumption in 2050. The IEA expects demand for biopower and biofuel to be about 90 EJ yr-1 in 2050. Based on their review that 500–1500 EJ yr-1 could potentially be produced, they do not expect meeting bioenergy demand sustainably to be much of a challenge.
The ICCT research looked at the assumptions used for parameters including crop yields, land availability, costs, and the inherent energy content of the biomass, which together account for most of the variation in the estimates produced by the studies surveyed by the IEA and IPCC. Most of the studies underestimated the area that would be needed for food production, resulting in high projections of land availability. Some modelers assumed the biomass grown on this land would be implausibly productive, while others were overly pessimistic. Production of biomass for energy will not be economically viable in all areas, but only two of the studies tried to account for this.
After adopting more plausible assumptions supported by the existing literature, accounting for conversion losses, and factoring in the probability that poor governance in unstable countries will limit production potential, the ICCT study concludes that a better estimate for total bioenergy potential would be 60 to 120 exajoules per year in the 2050 timeframe. This is equivalent to around 10%–20% of today’s global energy usage and is considerably lower than the high estimates cited in the IPCC surveys and from other similarly optimistic research studies.
The ICCT study’s authors stressed that this is an estimate of the highest amount of biomass that could be produced globally in future decades based on the basic constraints that they analyzed. “While this level of production of biomass for energy could potentially be achieved in 2050 if all governments make deployment a high priority and if significant investments are made in production, harvesting, and conversion technologies,” said Searle, “the amount of biomass we’re likely to produce is much lower.” One implication of this, the authors pointed out, is that IEA’s projection for about 90 EJ yr-1 of demand for bioenergy in 2050 will likely be difficult to meet sustainably.
The results of the study show that while biomass energy is likely to have a role in achieving long-term climate goals, it can only be part of the solution in any sector. “For transportation, this reminds us that while sustainable low-carbon biofuels are critically important, there is also a need to reduce oil consumption through other measures like greatly-increased efficiency and the use of battery and fuel cell electric vehicles,” said Searle.
Download the paper at onlinelibrary.wiley.com/doi/10.1111/gcbb.12141/abstract.