The role of biomass in a low-carbon energy system: capturing the complexity of biobased options, land use and carbon balances in an energy system model demonstrated for Brazil

Biomass is considered an important climate change mitigation measure. National energy system models are used to provide insight in the role of biomass to mitigate climate change. However, in those models biomass is modelled too simplistic, especially considering bioenergy-related land use change (LUC) emissions, mainly because they are place- and time dependent. By integrating the place- and time-dependent biomass supply potential in the model, as well as the associated LUC emissions, insight is provided in; i) how much biomass can be used to meet energy demand, ii) the associated LUC emissions, and iii) the energy system costs. The role of CO2 capture and storage in the subsurface in combination with biomass conversion (BECCS) is also analyzed. Brazil is used as a case study.
This research shows that biomass can supply between 5-10 EJ of the final energy demand in 2050 (35-60% of the total). Of this, between 0.5-7 EJ is supplied from new bioenergy plantations, with emission factors between 5-15 kg CO2-eq. per GJ of primary biomass. The large bandwidth is caused by:
• Intensification of agriculture: with a high intensity, land becomes available for new bio-energy plantations. As a result, little natural land (with a high carbon penalty) is needed;
• A CO2 penalty for natural succession on former farmland
• The CO2 injection rate of BECCS
When there is limited biomass supply with a low CO2 footprint, the costs for the energy system increase significantly because the industry and transport sector must be extensively electrified to achieve CO2 targets.