Assessing the economic efficiency of bioenergy technologies in climate mitigation and fossil fuel replacement in Austria using a techno-economic approach

Highlights: → Costs of GHG mitigation and fossil fuel replacement of bioenergy are assessed. → Technologies include heat, CHP and biofuel production plants of different sizes. → Abatement costs vary widely and depend on numerous parameters. → Heat generation and (under favourable conditions) CHP are most efficient. → Wood-based biofuels show low abatement quantity per unit of feedstock used. -- Abstract: The core issues of the Austrian energy policy agenda include reducing greenhouse gas (GHG) emissions and dependence on fossil fuels. Within this study, the costs of GHG mitigation and fossil fuel replacement (abatement costs) of established and upcoming bioenergy technologies for heat, electricity and transport fuel production are assessed. Sensitivity analyses and projections up to 2030 illustrate the effect of dynamic parameters on specific abatement costs. The results show that the abatement costs of wood-based heat generation technologies substituting oil-fired boilers and gas-fired heating plants, respectively, are in the range of -45 Euro per ton CO2-equivalent ( Euro /t CO2-eq.) and -11 Euro per MW h higher heating value ( Euro /MW hHHV) to 93 Euro /t CO2-eq. and 24 Euro /MW hHHV. Heating systems around 50 kW show the lowest abatement costs. For combined heat and power (CHP) plants, two different cases with regard to heat utilization are assumed. In an optimal mode (100% of generated heat displaces fossil fuel-based heat production), abatement costs of wood-based technologies, substituting electricity from modern combined cycle gas turbines, range from 5 Euro /t CO2-eq. and 1 Euro /MW hHHV to 201 Euro /t CO2-eq. and 38 Euro /MW hHHV. Representative values of typical CHP plants with a capacity of 1 MWel and more are in the magnitude of 50 Euro /t CO2-eq. and 10 Euro /MW hHHV. Under less favorable conditions (3000 heat full load hours per year), abatement costs of typical plants are around 100 Euro /t CO2-eq. and 17 Euro /MW hHHV higher. The costs of GHG mitigation and fossil fuel saving with established transport fuels (biodiesel and ethanol) range from 71 Euro /t CO2-eq. and 8 Euro /MW hHHV to 200 Euro /t CO2-eq. and 82 Euro /MW hHHV. For liquid fuels from lignocellulosis, abatement costs are estimated 147 Euro /t CO2-eq. and 38 Euro /MW hHHV to 240 Euro /t CO2-eq. and 59 Euro /MW hHHV. The abatement costs of synthetic natural gas are found to be significantly lower: 75 Euro /t CO2-eq. and 14 Euro /MW hHHV to 128 Euro /t CO2-eq. and 23 Euro /MW hHHV. The results suggest that heat generation and - given favorable conditions - CHP generation are the most cost-efficient options for reducing GHG emissions and fossil fuel dependence in Austria. A core advantage of CHP is higher quantities of abatement per unit of biomass used. In contrast, this is found to be the main drawback of synthetic transport fuels from wood.