Cost-Optimal Use of Bioenergy Under a Stringent Climate Stabilization Target

Using a global energy model describing the bioenergy sector in detail, this chapter examines the cost-optimal use of modern bioenergy over the period 2010-2100 under a 400 ppmv CO₂ stabilization constraint and its potential contribution to satisfying this stringent constraint. The following three main results are obtained. First, it is cost-optimal to use modern bioenergy largely to generate heat and replace direct coal use until around 2040. As second-generation bioenergy conversion technologies and CO₂ capture and storage (CCS) technologies become mature in the second half of the century, it becomes cost-optimal to produce biofuels and electricity using these technologies. All biomass gasification-based conversion technologies are combined with CCS (called BECCS) from 2060. Second, introducing modern bioenergy, particularly the strategy of negative CO₂ emissions provided by BECCS, makes a substantial contribution to stabilizing the atmospheric CO₂ concentration at 400 ppmv in 2100 and is a robust future technology option under such a stringent climate stabilization constraint. However, from around 2060, bioenergy supply potentials place a severe limit on the amount of modern bioenergy produced. Third, under the 400 ppmv CO₂ stabilization constraint, BECCS holds a large share of the global amount of CCS throughout the time horizon and offers great flexibility in the timing of CO₂ reductions, whose value is estimated to be as high as $13.3 trillion in constant 2000 US dollars. A significant portion of the CO₂ capture is implemented in now-developing regions, implying the importance of the effective transfer of CCS technologies to nowdeveloping regions for achieving stringent climate stabilization targets.

Keywords: Global warming, energy, supply, energy supply security, cost optimal use, bioenergy, energy policy, stringent climate constraint, CO₂ neutral, global energy system, optimization, model, alternative fuel, sensitivity analysis, stabilization, target.