Sustainable renewable urban energy system : South Karelia

Abstract

This master’s thesis examines the environmental performance of South Karelia’s existing urban energy system, focusing on electricity and district heating systems. Current condition of South Karelia in 2023 was built as the reference scenario and introduced three more scenarios targeting on replacing fossils with renewable sources. Although the current energy system has a high renewable energy share of 92%, it was considered of 3 scenarios with the renewable energy share of 93%, 97% and 100% respectively. Moreover, electrification of the system was also considered for this process of energy transition. Solar energy was also introduced to the system, where the existing system was not consuming solar power for electricity generation.

A life cycle assessment (LCA) was carried out using GaBi software to assess and compare the climate change impacts of each process and each scenario. Electricity and district heating systems modelled for the current condition resulted their emissions as 0.0522 kgCO₂-eq/kWh and 0.0283 kgCO₂-eq/kWh. Electricity system resulted 0.0140 kgCO₂-eq/kWh of emissions for the scenario with 100% renewable energy, which shows a 73% improvement in the performance compared to the current system. The district heating system shows 0.0048 kgCO₂-eq/kWh with an improvement of performance in 83% compared to the current scenario. The results presents that the emissions can be changed solely with the changes in the fuel mix even without any efficiency enhancements or technological modifications, showing the system’s potential for decarbonization with the use of renewable alternatives.