City energy planning: Modeling long-term strategies under system uncertainties

Cities are facing the dilemma of fulfilling energy service demands for their rapidly growing population while also working towards climate mitigation efforts. City energy planning is essential to deal with this dilemma. Thus, this study explores the role of city energy plans on future cost-efficient energy systems. A technology-rich cost-optimization model was developed using TIMES with intra-sectoral and inter-sectoral interactions and applied to the Gothenburg energy system. The model outcomes are investigated with the application of policy-driven scenarios and further tested under system uncertainties and price sensitivities identified using a participatory approach. Heating sector developments include DH production based on biomass CHP and heat pumps combined with improved building energy efficiency. Cost-efficient transport sector developments show a rapid deployment of biofuel vehicles, followed by increasing electrification later in the time horizon. With the applied uncertainties, different cost-optimal district heat production mixes and heating supply solutions are observed, providing alternative planning strategies. The model results also signify competition of biomass and electricity among sectors in their development pathways. The modeling outcomes enable decision-makers to assess various energy systems transition strategies from a long-term perspective.