Comparative review of multi-energy systems modeling tools for scenario analysis toward climate neutrality: Case studies, achievements, and challenges

Climate-neutrality planning requires modeling tools that connect long-term investment, multi-sector demand and emissions, power-system operation, and grid-security assessment. This structured review examines six widely used platforms such as PyPSA, Julia/JuMP, GAMS, TIMES, DIgSILENT PowerFactory, and LEAP for large-scale multi-energy-system analysis. Based on 100 cited sources, the platforms are qualitatively compared in terms of temporal and geographical resolution, optimization structure, data requirements, sector coverage, solver flexibility, and application domains. Kazakhstan's coal phase-down and renewable-energy expansion toward 2060 provide the practical context for discussing their suitability and complementarity. The review demonstrates that no single platform can fully represent all planning, operational, environmental, and engineering aspects of a climate-neutral energy system. TIMES and LEAP are particularly suitable for long-term demand, policy, and emissions scenarios; PyPSA, Julia/JuMP, and GAMS support investment and dispatch optimization with different levels of flexibility and transparency; and DIgSILENT PowerFactory provides detailed power-flow, contingency, protection, and dynamic-security analysis. The findings support a staged modeling workflow in which long-term transition pathways are linked to network-constrained optimization and subsequent engineering validation. This application-oriented comparison clarifies the respective strengths and limitations of the reviewed tools and provides guidance for selecting complementary platforms for large-scale energy-transition studies.