Parallel Session 14 – Sustainability of Bioenergy Pathways

Thursday 24 October 2024, 11.30-13.00 BRT

Moderators: Zoe Harris (University of Surrey, UK) and Tiziana Pirelli (FAO/GBEP, Italy)

Speakers:

Selected conclusions and key messages:

  • Bioenergy has an important role in the clean energy transition and in the substitution of fossil fuels; most scenarios that align with the goals in the Paris Climate agreement indicate a bioenergy share between 15 and 25% in overall primary energy use in 2050. Climate effects of bioenergy depend on: the biomass feedstock (residues, dedicated crops, type of production system, …); conversion technologies and co-products; and effects of bioenergy on carbon stocks, land use and the energy system. In any analysis of climate impacts, it is key to take a broad enough system boundary and to consider a credible reference system, i.e. what would be the land use without bioenergy; how would carbon stocks in forests evolve without demand from the bioenergy side; how would the energy system (electricity, heat, transport energy) evolve without bioenergy; and what would be the reference fate of the biomass that is used. Divergence in these assumptions is often the reason for widely different results (picturing bioenergy from ‘worse than coal’ to climate neutral). Moreover, it is important to look at the whole bioeconomy to understand the impacts of bioenergy, as the feedstocks for bioenergy are often a residue or co-product. For example, the climate impact of sustainable forest management is determined by the impact on carbon storage in the forest, the storage of carbon in long-lived forest products, and by the replacement of GHG-intensive materials and fossil fuels through bioenergy and other forest products.

  • The GREET LCA model examines life-cycle impacts (i.e., energy use and emissions) of vehicle technology/fuel combinations in road, air, rail, and maritime transportation. It covers an extensive and growing list of energy systems, including a variety of biofuel technology pathways. This model informs policies and regulations in the USA, plus Canada’s Clean Fuel Regulation. In the comparison of life cycle GHG emissions of ethanol, it is clear that the feedstock makes the big difference. GHG emissions of biofuels have improved over the years with improved practices in feedstock production and in processing facilities. It is possible to obtain negative emissions from corn-based ethanol when CO2 emissions from the mill are captured and stored. Two approaches are used in regulations/programs to address Induced Land-Use Change (iLUC) GHG emissions: (1) quantify potential iLUC GHGs (applied in the US and by ICAO) or (2) risk-based approach to prevent high-risk ILUC with sustainability criteria (applied in the EU, Canada, Brazil and in IMO guidelines). Mind that estimated ILUC emissions saw a downward trend as a result of better developed, calibrated economic models to incorporate up-to-date data.
  • Life Cycling Thinking (LCT) is about going beyond the traditional focus on production site and manufacturing processes to include environmental, social and economic impacts of a product over its entire life cycle. The main goals are to reduce a product’s resource use and emissions to the environment as well as improve its socio-economic performance through its life cycle. This way a connection can be made to the impact on several Sustainable Development Goals (SDGs). An example was shown for double-cropped maize ethanol in Brazil, assuming an expansion from 2.9 to 8 billion liters of ethanol, and in addition the production of 600 MWh of electricity, 4 million tons of DDGS and 0.16 million tons of maize oil.
  • An Integrated Sustainability Assessment Platform focuses on the ecological transition, addressing synergies and trade-offs to identify solutions with net positive impacts. It includes biodiversity and ecosystem services, as well as socio-economic variables. In Brazil, there has been an ecological approach for sustainable expansion, consistent with the conservation of biodiversity and food/feed production (Agro-ecological Zoning). This has had positive impacts in carbon stocks and water availability, and medium impacts on biodiversity. Conclusions are that a multifunctional landscape approach is paramount to promote an ecological transition; an integrated framework with ecosystem services is needed for sustainable development and should in future also incorporate social impacts; recognition and quantification of synergies and trade-offs are central.
  • Agriculture is part of the solution, considering energy for agriculture and energy from agriculture, as well as sustainability and efficiency in agriculture. Some conclusions of GBEP Sustainability Indicator (GSI) implementation in various countries and bioenergy pathways:
    • Biogas in Viet Nam: anaerobic digesters for biogas production, mainly fed with agrifood waste and residues (pig manure), are common in the country and represent a win-win solution, especially at household level where they enhance access to clean cooking and light. Use of bio-CCU from biogas at large scale level for beverage production, represent a successful example of integrated bioenergy and bioeconomy systems. Recommendations are to enhance plant and co-products management capacity to improve efficiency of plants, and to increase the availability of capital to allow for electricity generation from biogas in medium-/large-scale livestock farms.
    • Bioethanol in Paraguay: GHG emissions of sugarcane- and corn-based bioethanol pathways can be further reduced through the adoption of climate-smart agricultural management practices that lead to sustainable crop intensification. Corn, cultivated as secondary crop, in rotation with soybean, allows for reduced impact on LUC and GHG emissions.
  • Overall, ensuring sustainability is key. Sustainability is the results of its three dimensions (environmental, economic and social) and it depends on both the spatial and temporal context. Stakeholder engagement is a powerful means to better understand the local context and priorities. Monitoring, through science-based approaches, can help to minimize bioenergy related risks and tradeoffs, and take out the best of opportunities. Providing data and information to inform the development of new policies could foster a further sustainable development of the sector. Building an enabling and stable policy framework is strongly required to attract investments, implement new technologies, foster RD&I and build consumers’ trust.