Sustainability assessment of heat and electricity generation from biomass in Turkey

  • Gulizar Balcioglu

Student thesis: Phd

Abstract

This research has assessed the environmental, economic and social sustainability of heat and electricity generation from biomass in Turkey. To give a broad perspective, it has considered a diverse range of feedstocks, including both wastes and energy crops, and their utilisation via various technologies (direct combustion, gasification, co-firing with lignite, anaerobic digestion (AD), landfilling and incineration). A detailed and comparative assessment of alternative bioenergy pathways has been first carried out using life cycle assessment (LCA) and life cycle costing (LCC) as well as the common economic parameters of project feasibility (i.e., net present value and payback time). These results have been then integrated into the scenario analysis and complemented with a social sustainability assessment. A system-level approach has been applied to identify the role of future biomass potential in a sustainable transformation of Turkey's heat and electricity sector. To assess the overall sustainability of current (2018) situation and future (2050) bioenergy scenarios, a multi-criteria decision analysis (MCDA) has been performed, integrating fourteen environmental, three economic and eight social sustainability indicators considered in this work. The environmental and economic sustainability results suggest that co-generation of heat and power (CHP) through direct combustion of biomass is the best option among the thermal conversion technologies, while AD is preferred for wet residues. Moreover, wood chips, maize stover and poplar with less energy- and material-intensive supply chain have the lowest impacts and costs, while the high biogas yield has a critical importance for the sustainability of AD of wet residues. Compared to the reference energy sources -natural gas heat and grid electricity-, significant savings in global warming potential and fossil fuel depletion impacts can be achieved by utilising biomass, except for landfilling of organic municipal wastes and AD of cattle slurry (with or without maize silage). On the other hand, all solid biomass-to-energy pathways have higher and terrestrial ecotoxicity potential than the reference energy sources, while AD leads to significantly higher marine eutrophication and acidification. Regarding the economic sustainability, all technologies are feasible, except wood pellet and miscanthus boiler and those using wheat straw. AD of wet residues and the biomass power plant using stover and wood chips also result in net profits under the current subsidies. The levelised costs of heat from biomass are 64-83% lower compared to the heat from natural gas, and bioelectricity is 10-30% cheaper than grid electricity, except for gasification and technologies using wood pellets and wheat straw. Overall, this study estimates that, if all available and potential biomass feedstocks in Turkey are utilised for heat and electricity generation, it could save 105.4 Mt CO2-eq. (or 20%) of annual greenhouse gas (GHG) emissions and $7.5 bn (or 59%) of fossil fuel import costs. Compared to the current situation, the amount of biomass resources is estimated to more than double in 2050 with a recoverable energy potential capable of meeting 21% of the future heat and electricity demand. Seven bioenergy mix scenarios have been developed considering preferences for the selection of technologies (established or still developing and separate or combined heat and power generation and feedstocks wastes and energy crops) at three different levels of contribution to the energy mix (5-17%). Results suggest that the increased use of biomass brings significant economic, environmental and social benefits compared to the business-as-usual (BAU) mix but with trade-offs. For most of the sustainability indicators, the scenarios considering the high deployment of bioenergy for CHP are the most sustainable options, reducing the global warming potential by 8%, energy costs by 12% and diversifying the energy mix relative to BAU
Date of Award1 Aug 2022
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorAdisa Azapagic (Supervisor) & Harish Jeswani (Supervisor)

Keywords

  • social sustainability assessment
  • life cycle costing
  • life cycle asssessment
  • sustainability
  • electricity
  • biomass
  • heat

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