Global climate change requires a transition of the energy system towards renewable solutions. The transformation in the German heat sector, responsible for over half of the final energy consumption in Germany, is stagnating and requires various individual solutions in a heterogeneous market. Besides varying technological requirements, various stakeholders with different interests influence the market development. Bioenergy delivers the major share of only 14% renewable heat today. In the future, this distribution is expected to change and the future role of bioenergy is uncertain. Biomass is limited and in competition between different usage options. Consequently, the sustainable utilization of the limited biomass potential in an efficient, cost optimal way is the challenge we are facing today.

Addressing this research gap, an energy system optimization model (ESOM) was set up. A focus is set on a detailed representation of the various technological bioenergy options and the heterogeneous heat sector under consideration of consumer choice and future uncertainties. Besides several scenario analysis, a comprehensive sensitivity analysis was conducted to determine the influence of uncertainties and identify robust solutions.

Through the outlined method, it is found that solid biomass, in the form of either wood chips, pellets, log wood or Miscanthus chips, is in all investigated cases a competitive option to fulfill the defined climate targets. Especially, the use of wood chips from residues and Miscanthus in high temperature industry applications is identified as the most robust option under all investigated uncertainties from a systems perspective. In these applications, renewable alternatives are rare and renewable power can more efficiently be used in other
heat sub-sectors.

Additionally, log wood technologies in the private household sector are found to be a competitive option, especially when consumer behavior is considered. However, this finding does not apply to houses with high insulation standards, in which economic factors are found to be predominant. Furthermore, hybrid CHP pellet systems are found to be a competitive option under the assumption of strongly increasing power prices. However, increasing power prices a likely to decelerate the heat transition as they lead to an economic advantage of natural gas technologies compared to power based renewable heat supply. Besides the power price, the future gas price development and the consideration of consumer behavior are identified as significantly influential on the future use of  bioenergy.

With the outlined thesis, novel methodological approaches are introduced, contributing to both, the uncertainty assessment in energy system analysis and the integration of consumer choice in ESOMs. The performed analyses in this thesis investigate a wide range of solutions and provide policy insights with a high level of confidence.