This study analyses the Ukrainian energy system in the context of the Paris Agreement and the need for the world to limit global warming to 1.5 °C. Despite ~84% of greenhouse gas emissions in Ukraine being energy- and process-related, there is very limited academic literature analysing long-term development of the Ukrainian energy system. This study utilises the TIMES-Ukraine model of the whole Ukrainian energy system to address this knowledge gap and to analyse how the energy system may develop until 2050, taking into current and future policies. The results show the development of the Ukrainian energy system based on energy efficiency improvements, electrification and renewable energy. The share of renewables in electricity production is predicted to reach between 45% and 57% in 2050 in the main scenarios with moderate emission reduction ambitions and ~80% in the ambitious alternative scenarios. The cost-optimal solution includes reduction of space heating demand in buildings by 20% in frozen policy and 70% in other scenarios, while electrification of industries leads to reductions in energy intensity of 26–36% in all scenarios except frozen policy. Energy efficiency improvements and emission reductions in the transport sector are achieved through increased use of electricity from 2020 in all scenarios except frozen policy, reaching 40–51% in 2050. The stated policies present a cost-efficient alternative for keeping Ukraine’s greenhouse gas emissions at today’s level.

In this study, we use a TIMES-Ukraine energy system-wide model to explore net-zero transition in Ukraine. The assessment considers the potential implications of the ongoing war in the country and analyzes how the achievement of ambitious mitigation goals could impact the indicators related to the Sustainable Development Goal on energy, SDG7 (Ensure access to affordable, reliable, sustainable and modern energy). Results suggest that the net-zero transition would help improve several SDG7 indicators, including increased share of renewables in total final energy consumption, and increased energy affordability in the long run. However, in the medium run, increasing energy prices and rising investment needs might challenge the net-zero transition in the country. Overall cumulative investment needs increase by around 23% over the analyzed time horizon with the major portion being concentrated within the 2030–2045 timeframe. Major efforts need to be made to ensure the availability of a wide range of options for clean and green energy financing in Ukraine, including a reduction of the bond yield rates, creation of the specialized funds to support the ‘green’ transition, as well as the creation of a more competitive domestic environment through increasing mitigation ambition. If successfully implemented, these will allow Ukraine to rebuild the domestic energy system in a more technologically advanced and climate-friendly way, at the same time further supporting the country’s sustainable development agenda.

The European Union established a legislative framework to facilitate the transition to low-carbon energy sources. As Ukraine aspires to join the EU, it is progressively adopting similar legislation. The extensive damage to Ukraine’s fossil fuel-based heat generation infrastructure necessitates the reconstruction of heating and cooling supply systems, with a focus on low-carbon energy sources, particularly heat pumps. Notably, Poland achieved the highest growth in installed heat pump capacities in Europe, offering valuable insights for Ukraine’s energy transition. This study employs the TIMES-Ukraine model to assess the potential proliferation of heat pumps within the country. The findings suggest that, if capital costs for heat pumps decrease, their adoption could accelerate more rapidly than biomass-fired heating systems, particularly in urban single-family homes and buildings lacking central heating systems, over the next decade. While high investment costs may slightly diminish the attractiveness of this technology for space heating, heat pumps consistently outperform biomass heating appliances and potential biomethane-sourced gas boilers.

The paper presents results of scenario modelling and assessment of energy transition to 2050 in the Zhytomyr territorial community (TC), which provides for a switching from fossil carbon based energy resources in the current TC energy system functioning to 100% use of renewable energy sources (RES) which meets all energy demands and supports the Sustainable Development of TC in accordance with the relevant UN goals. For this purpose, the optimizational economic and mathematical TIMES-Zhytomyr model (no analogues in Ukraine), based on the TIMES-Ukraine model, was developed. It includes 647 energy technologies that are currently available or may be presented in the coming years in Ukrainian market. For the development of the TIMES-Zhytomyr model, a low-available local energy statistics was processed. As a result, the first energy balance by the form of the International Energy Agency for the large Ukrainian city and the basic energy-technological system of Zhytomyr TC were developed. Using the TIMES-Zhytomyr model, based on foreign and Ukrainian experience, for the first time, four scenarios of Zhytomyr TC energy system development were designed and modelled, covering all economic sectors and household sector (population). The first one is the Baseline scenario, which displays the possible dynamics of the energy system development without a purposeful energy efficiency policy, the development of RES, etc. Three other scenarios are aimed at studying TC’s transition capabilities by 2050 to 100% renewable energy and environmentally friendly technologies use. The results of modelling confirmed that the available renewable energy resource and technological potential allows Zhytomyr TC to perform the energy transition to 2050 in an economically feasible and socially acceptable way, significantly reducing energy and carbon intensity of the local economy, substantially eliminating GHG emissions, increasing the welfare of citizens and creating at least 10 thousand new workplaces. It will also significantly contribute to Zhytomyr TC to reach at least 10 of the 17 UN Sustainable Development Goals. The research results presented, due to a significant novelty and large-scale relevance of the task, are essential in both the theoretical and practical significance. They can be used by scientists for their research and by authorities and experts for development of local, regional or national level strategies, plans or programs of economic, energy, transport, climate and ecology scope. It can also be considered as one of the first steps in preparation of a comprehensive strategy for the Zhytomyr TC development to achieve climate neutrality in accordance with the current objectives of the European Union.