#Bioenergy and Carbon Management

#Bioenergy Demand

Bioenergy is a key technology for achieving economy-wide deep decarbonization targets, primarily through the biofuels pathway. Figure 37 shows the range in total delivered bioenergy by category across scenario and the sensitivity of the scale of its role to input assumptions about bioenergy resources and conversion costs. With greater bioenergy supply and lower conversion costs, biofuels could become competitive with petroleum even in a reference scenario, expanding further with increased incentives for low-carbon fuels in net-zero scenarios. In scenarios with limited sectoral flexibility, more bioenergy is used for renewable natural gas, while more flexible targets direct most bioenergy to liquid fuels. These renewable liquid fuels are used primarily in the transportation sector, but they can also serve as low-carbon alternatives to gas in industrial boilers and combustion turbines in the power sector.

#CO₂ Removals

The use of bioenergy is closely linked to options for CO₂ removal (CDR) or negative emissions. In net-zero scenarios with economy-wide flexibility to allocate reductions and removals across sectors, the cost-effective trade-off between direct emissions reductions and CDR results in around 1 GtCO₂. With more optimistic bioenergy costs, most of this total comes from the use of bioenergy with CCS, particularly for liquid fuels. With less optimistic bioenergy costs, direct air capture with carbon storage (DACCS) is deployed. Note that bioenergy resources are modeled with an increasing supply curve, so the trade-off between bio-CCS and DACCS is driven by the shape of this curve relative to the quantity of bioenergy demanded. In the optimistic case, the cost of CDR through bio-CCS does not rise to the levelized cost of DACCS, which has a “flatter” supply curve (i.e. costs do not increase with quantity supplied). With less optimistic bioenergy assumptions, the supply curve is steeper, and DACCS is an economic option.