Enhancing Consumer Energy System Reliability Through Integrated OEE and NPHR Evaluation of Steam Turbine Performance

Steam Power Plants (PLTUs) play a vital role in ensuring a reliable electricity supply by converting thermal energy into electrical energy through steam turbine systems. However, the operational performance of turbine units is often challenged by efficiency losses that affect energy utilization and plant productivity. This study evaluates the operational efficiency of the 2×100 MW steam turbine units at PT PLN Indonesia Power Ombilin Business Unit using performance test data collected throughout 2024. The analysis focuses on key performance indicators, including Turbine Efficiency, Net Plant Heat Rate (NPHR), and OEE, to identify factors limiting optimal performance. The results indicate that the average turbine efficiencies of Units 1 and 2 were 92.36% and 86.66%, respectively, below the expected target. The calculated NPHR values were 2.985 for Unit 1 and 3.147 for Unit 2, while OEE values reached 76.98% and 69.72%, categorizing within medium-performance range. Further investigation revealed that fuel quality variations, equipment condition, maintenance practices, and turbine operation processes significantly influenced efficiency degradation. Several improvement are proposed to enhance operational reliability, optimize energy utilization, and reduce performance losses. The study demonstrates the importance of integrating performance evaluation metrics with continuous operational improvement strategies to achieve higher efficiency standards. The proposed initiatives are expected to increase OEE performance toward the benchmark value of 85% while maintaining NPHR within operational targets. These findings provide valuable insights for quality control, energy conservation, and sustainable operational planning in coal-fired power generation systems, supporting the development of more reliable and efficient energy infrastructure.