Bridging gaps in bioenergy: Deploying system analysis to investigate potential biomass supply, demand and greenhouse gas mitigation scenarios from a national, European and global perspective

Abstract

In transition towards a sustainable energy system with deep reductions in greenhouse gas (GHG) emissions and reduced consumption of fossil fuels, substitution of fossil energy carriers with biomass is considered one of the most important options. In the last decade, fossil energy and GHG mitigation policies and volatile fossil fuel prices have driven rapid growth of modern biomass. In contrast to local, traditional biomass uses for heating and cooking in developing countries, modern biomass uses are often geographically remote from the locations that have the larger economic biomass supply potentials. This has already resulted in rapid growth of trade of solid and liquid biomass sources, especially in the European Union (EU) and will likely continue to grow in the future. The prospective growth of bioenergy and geography of trade are still highly uncertain. This thesis aims to bridge some of the knowledge gaps on the deployment of bioenergy at the national and European level by means of system analysis. A key focus of this thesis are the high variabilities of cost and GHG balances of bioenergy systems, which can both be caused by methodological choices, the locations of feedstock production, logistics, the conversion system and rate of technological learning. Bottom-up spreadsheet tools have been developed to compare the variability in energy and GHG balance of different biofuel production systems with variations in key assumptions and methods to account for co-products (Chapter 2). In Chapter 3, a bottom-up accounting tool is used in combination with the computable general equilibrium model LEITAP to assess future scenarios of avoided fossil energy and GHG emissions next to direct and indirect economic effects of bioenergy deployment for the Netherlands to 2030. Spatially explicit approaches are developed to account for the geographic implications of feedstock supply, logistics and demand. For the Southeast of the U.S., a key exporting regions of wood pellets, the potential of alternative, low-value wood fiber sources has been assessed taking into account the dispersed supply of wood fiber resources and locations of pellet production plants (Chapter 4). For long distance international transport of biomass, this thesis describes the development of the BIT-UU model that can be used to calculate the cost and GHG emissions of international biomass transportation taking into account the available infrastructure (road, rail, inland waterways, sea). This model is linked to the European renewable energy model Green-X model in Chapter 5 to assess the future role of domestic use and trade of biomass in context of renewable energy policies in the EU. Furthermore, the BIT-UU model is linked to the U.S. based Biomass Logistic Model (BLM) to assess the cost and GHG emissions of intercontinental lignocellulosic feedstock supply chains between the U.S. and Europe in Chapter 6. The developed methods, tools and linkages to (established) modeling frameworks provide insights into the role of domestic and internationally traded biomass in fulfilling national and European renewable energy targets, economic effects, GHG mitigation and consequences of methodological choices and input assumptions to the life-cycle GHG performance and energy balance.