Abstract
This study compares long term generation/investment patterns in a simplified representation of Romania’s electricity sector between 2025 and 2050. A deterministic OSeMOSYS/MUIO model is used to examine a reference emissions ceiling, a terminal zero emissions target and an accelerated emissions pathway. The scenarios are conditional model experiments that share exogenous demand and technology assumptions. The model includes Romania’s main electricity generation technologies: coal, natural gas, hydropower, nuclear power, wind, and solar photovoltaics, and minimizes the total discounted system cost subject to technical, economic, and environmental constraints. Three likely scenarios are analyzed in the paper: first, a business-as-usual scenario without emission limits, a gradual decarbonization scenario, and finally an accelerated decarbonization scenario. Earlier emissions constraints shift investment toward low emission technologies and reduce modeled cumulative emissions, but they also increase the archived discounted objective under the stated assumptions. The model contains one aggregated node and eight time slices and does not represent explicit storage, electricity imports or exports, curtailment, network congestion, unit commitment or chronological dispatch. The results therefore describe investment trade-offs within the specified model boundary and do not establish operational adequacy, resilience or implementation feasibility.