<![CDATA[General Background: Combined-cycle electricity generation supports energy supply but relies on natural gas and High-Speed Diesel, producing emissions, wastewater, and hazardous waste that require environmental control. Specific Background: PLN Indonesia Power UBP Grati operates a gas-and-steam power plant in which internal generation activities contribute to climate change, ecotoxicity, and other environmental categories. Knowledge Gap: The ecological burden and associated monetary environmental cost of these gate-to-gate generation processes require systematic quantification to support process-level improvement. Aims: This study applied Life Cycle Assessment with a gate-to-gate boundary, SimaPro 10, and Eco-Indicator 99 to identify dominant environmental categories, calculate eco-cost, and assess eco-efficiency. Results: Total eco-cost reached IDR 2,127,458, comprising IDR 2,047,455 for human health, IDR 54,629 for ecosystem quality, and IDR 25,374 for resources. Ecotoxicity recorded the highest weighting value at 108 Pt, while the Eco-Efficiency Index, Eco-Cost Value Ratio, and Eco-Efficiency Ratio Rate were 32.84, 0.030, and 0.7%, respectively. Novelty: The study integrates gate-to-gate LCA, eco-cost, and eco-efficiency indicators within the operational context of UBP Grati. Implications: The findings support solar energy use, combustion management, routine maintenance, and activated-carbon treatment of wastewater as environmental improvement options identified in the study. Highlights: Ecotoxicity recorded the highest weighting value at 108 Pt. The total monetary environmental burden reached IDR 2,127,458. EEI was 32.84, EVR 0.030, and EER 0.7%. Keywords: Eco Cost, Green Manufacturing, Life Cycle Assement, PLTGU, Simapro]]>
