The Effect of Cooling Water Inlet Emperature (CWIT) on Efficiency USC 1050 MW Steam Power Plant

  • Hiro Nayaparana Master Program of Energy, School of Postgraduate Diponegoro University, Indonesia
  • Purwanto Master Program of Energy, School of Postgraduate Diponegoro University, Indonesia
  • Endang Kusdiyantini Master Program of Energy, School of Postgraduate Diponegoro University, Indonesia
Keywords: Cooling Water Inlet, Temperature (CWIT), Thermal Efficiency, Net Plant Heat Rate (NPHR), Fuel Cost Penalty

Abstract

This research explores the impact of the Cooling Water Inlet Temperature (CWIT) on the efficiency and operational costs of the Ultra Supercritical (USC) 1050 MW Coal-Fired Power Plant (PLTU) in Indonesia. With Indonesia's growing dependence on PLTU as a primary source of electricity, maintaining operational efficiency is critical. The study was conducted at the PLTU Jawa 7 change to 1050 USC type power plan using quantitative descriptive-analytical methods, and data was collected from both the Distributed Control System (DCS) and BMKG. The analysis focuses on how varying CWIT affects condenser pressure, thermal efficiency, Net Plant Heat Rate (NPHR), and fuel consumption. The findings indicate that an increase in CWIT results in higher condenser pressure, reduced vacuum quality, and lower thermal efficiency, leading to an increase in NPHR and higher fuel costs. Furthermore, the research assesses the economic impact, highlighting daily fuel cost penalties and opportunity losses due to reduced electricity generation. The study also provides strategies for mitigating the negative effects of CWIT, including enhanced cooling water flow, condenser cleaning, and the addition of cooling towers. In conclusion, the research emphasizes the importance of controlling CWIT to optimize plant performance and reduce operational costs.

References

Adven Brilian, V., Khasani, & Pranoto, I. (2024, September). Techno-economic comparisons of organic Rankine cycle and supercritical carbon dioxide cycle to utilize brine waste heat in Ulubelu geothermal power plant, Indonesia. In IOP Conference Series: Earth and Environmental Science (Vol. 1395, No. 1, p. 012003). IOP Publishing. https://doi.org/10.1088/1755-1315/1395/1/012003

Albdour, S. A., Addad, Y., Alyammahi, N., & Afgan, I. (2024). Steam condensation heat transfer in the presence of noncondensable gases (NCGs) in nuclear power plants (NPPs): A comprehensive review of fundamentals, current status, and prospects for future research. International Journal of Energy Research, 2024(1), 2880812. https://doi.org/10.1155/2024/2880812

Ali, A. (2025). Evaluating the Impact of Renewable Energy Integration on the Operational Efficiency and Economic Viability of Thermal Power Plants. International Journal of Social Sciences Bulletin, 3(6), 341-351.

Almeshaal, M. A., & Choubani, K. (2023). Using the Log Mean Temperature Difference (LMTD) and ε-NTU methods to analyze heat and mass transfer in Direct Contact Membrane Distillation. Membranes, 13(6), 588. https://doi.org/10.3390/membranes13060588

Apriliyanti, I. D., Nugraha, D. B., Kristiansen, S., & Overland, I. (2024). To reform or not reform? Competing energy transition perspectives on Indonesia's monopoly electricity supplier Perusahaan Listrik Negara (PLN). Energy Research & Social Science, 118, 103797. https://doi.org/10.1016/j.erss.2024.103797

Ben-Mansour, R., El-Ferik, S., Al-Naser, M., Qureshi, B. A., Eltoum, M. A. M., Abuelyamen, A., ... & Ben Mansour, R. (2023). Experimental/numerical investigation and prediction of fouling in multiphase flow heat exchangers: a review. Energies, 16(6), 2812. https://doi.org/10.3390/en16062812

Bilgili, M., Tumse, S., & Nar, S. (2024). Comprehensive overview on the present state and evolution of global warming, climate change, greenhouse gasses and renewable energy. Arabian Journal for Science and Engineering, 49(11), 14503-14531. https://doi.org/10.1007/s13369-024-09390-y

Cengel, Y. A., & Boles, M. A. (2015). Thermodynamic Property Relations. Thermodynamics: an engineering approach, 658-661.

Charamba, A. N., Kumba, H., & Makepa, D. C. (2025). Assessing the opportunities and obstacles of Africa’s shift from fossil fuels to renewable sources in the southern region. Clean Energy, 9(3), 74-93. https://doi.org/10.1093/ce/zkae121

Djaeni, M., Windarta, J., & Muqorrobin, R. (2025). The Analysis of Changes in Calorific Value of Coal in the Coal Flow Coal Feeder and Net Plant Heat Rate (NPHR). ASTONJADRO, 14(1), 339-348. https://doi.org/10.32832/astonjadro.v14i1.18136

Djazuli, F. L., & Rahmawati, S. (2025). Study Of Water Distribution Patterns and Temperature Changes in Waters Around Power Plant (Case Study of PLTU Tanjung Jati B Unit 5 & 6). International Journal of Offshore and Coastal Engineering (IJOCE), 9(2).

Dong, W. S., Ismailluddin, A., Yun, L. S., Ariffin, E. H., Saengsupavanich, C., Maulud, K. N. A., ... & Yunus, K. (2024). The impact of climate change on coastal erosion in Southeast Asia and the compelling need to establish robust adaptation strategies. Heliyon, 10(4). https://doi.org/10.1016/j.heliyon.2024.e25609

Elkelawy, M., Draz, A. M., Seleem, H. E., & Hamouda, M. A. (2025). Performance characteristics of diesel engine power plants: efficiency, emissions, and operational flexibility. Pharos Engineering Science Journal, 2(1), 1-11. https://doi.org/10.21608/pesj.2025.352971.1009

Firdaus, A. (2021). Assessment of tidal power opportunities in Indonesian waters (Doctoral dissertation, University of Oxford).

Frank, S., Heinze, T., Pollak, S., & Wohnlich, S. (2021). Transient heat transfer processes in a single rock fracture at high flow rates. Geothermics, 89, 101989. https://doi.org/10.1016/j.geothermics.2020.101989

Garcia-Soto, C., Cheng, L., Caesar, L., Schmidtko, S., Jewett, E. B., Cheripka, A., ... & Abraham, J. P. (2021). An overview of ocean climate change indicators: Sea surface temperature, ocean heat content, ocean pH, dissolved oxygen concentration, arctic sea ice extent, thickness and volume, sea level and strength of the AMOC (Atlantic Meridional Overturning Circulation). Frontiers in Marine Science, 8, 642372. https://doi.org/10.3389/fmars.2021.642372

Jørgensen, B. N., & Ma, Z. G. (2025). Energy efficiency and decarbonization strategies in buildings: a review of technologies, policies, and future directions. Applied Sciences, 15(21), 11660. https://doi.org/10.3390/app152111660

Kulakov, E. N., Gaev, V. D., Kazarov, G. I., Sukhorukov, Y. G., & Popov, A. V. (2023). More efficient heat recovery from the condensate of reheaters at new and operating nuclear power plants (NPPs). Thermal Engineering, 70(1), 23-31. https://doi.org/10.1134/S0040601523010032

Lehr, J., & Rehdanz, K. (2024). The effect of temperature on energy related CO2 emissions and economic performance in German industry. Energy Economics, 138, 107818. https://doi.org/10.1016/j.eneco.2024.107818

Ma, X., Zhao, X., Zhang, Y., Liu, K., Yang, H., Li, J., ... & Liu, Z. (2022). Combined Rankine Cycle and dew point cooler for energy efficient power generation of the power plants-A review and perspective study. Energy, 238, 121688. https://doi.org/10.1016/j.energy.2021.121688

Milovanović, Z., Branković, D., & Janičić-Milovanović, V. (2024). of optimal reliability of water supply system at condensing thermal power plant. System Reliability Analysis: Transition from Binary to Multi-state Models, 9.

Moh Jaelani, K., Awliya, G., Brilian, V. A., Hosnan, R., & Siregar, L. R. (2022). Techno-economic analysis on the development of an add-on geothermal power plant by optimizing the exhaust back pressure turbine steam in Ulumbu field, East Nusa Tenggara, Indonesia. Ghiffari and Brilian, Vincentius A. and Hosnan, Roiyatul and Siregar, Lambok R., Techno-Economic Analysis on the Development of an Add-On Geothermal Power Plant by Optimizing the Exhaust Back Pressure Turbine Steam in Ulumbu Field, East Nusa Tenggara, Indonesia. https://doi.org/10.2139/ssrn.4054804

Morozyuk, L., Sokolovska-Yefymenko, V., Moshkatiuk, A., Ierin, V., & Basov, A. (2023). Experimental study and analysis of an air-cooled condenser with the fouling on the heat exchange surface for small-scale commercial refrigeration systems. International Journal of Air-Conditioning and Refrigeration, 31(1), 18. https://doi.org/10.1007/s44189-023-00034-8

Nedismanto, A., Hariyadi, R., Arief, K. J., & Muharni, R. (2023, April). Turbine Blade Modification to Obtain Required NPHR Value with Low-Quality Coal Energy Source at Gorontalo Power Plant. In The 6th Mechanical Engineering, Science and Technology (MEST 2022) International Conference (p. 276). Springer Nature. https://doi.org/10.2991/978-94-6463-134-0_26

Neka, W., Setyohadi, D., & Parmawati, R. (2025). Spatio-Temporal Correlation of Sea Surface Temperature and Chlorophyll-a with East Seasonal Upwelling in the Bali Strait Using Aqua-MODIS Data. Egyptian Journal of Aquatic Biology & Fisheries, 29(5). https://doi.org/10.21608/ejabf.2025.427220.6649

Orysiak, E., Figas, J., Prygiel, M., Ziółek, M., & Ryłko, B. (2025). Analysis of Hydrological and Meteorological Conditions in the Southern Baltic Sea for the Purpose of Using LNG as Bunkering Fuel. Applied Sciences, 15(13), 7118. https://doi.org/10.3390/app15137118

Pawar, A., & Dondapati, R. S. (2026). An integrated review of multiphysics issues and challenges in the design and implementation of gas turbine blades for jet engine applications. International Journal of Turbo & Jet-Engines, 43(2), 391-403. https://doi.org/10.1515/tjj-2025-0104

Polyvianchuk, A., Gritsuk, I., Polyvianchuk, N., Yefimov, O., Romanenko, S., Kapustenko, P., & Arsenyeva, O. (2025). Optimized step-by-step modernization of residential heating systems: a multi-period investment strategy for energy efficiency and cost reduction. Thermal Science and Engineering Progress, 64, 103799. https://doi.org/10.3303/CET24114112

Portugal-Pereira, J., Esteban, M., & Araújo, K. (2024). Exposure of future nuclear energy infrastructure to climate change hazards: A review assessment. Energy Strategy Reviews, 53, 101365. https://doi.org/10.1016/j.esr.2024.101365

Pospolita, J., Kuczuk, A., Widera, K., Buryn, Z., Cholewa, R., Drajczyk, A., ... & Smejda, R. (2022). Water Losses in the Condenser Cooling System at the 905 MWe Power Unit. Energies, 15(16), 5969. https://doi.org/10.3390/en15165969

Prabowo, Z. N., Mutianingsih, P., & Kurniawan, H. (2025, April). The Ocean Energy Potential in the Area of Early-Retirement Asset Coal-Fired Power Plants Owned by PT PLN (Persero). In IOP Conference Series: Earth and Environmental Science (Vol. 1472, No. 1, p. 012030). IOP Publishing. https://doi.org/10.1088/1755-1315/1472/1/012030

Qiao, X., Zhang, K., & Huang, W. (2025). Impacts of Climate Change on Oceans and Ocean-Based Solutions: A Comprehensive Review from the Deep Learning Perspective. Remote Sensing, 17(13), 2306. https://doi.org/10.3390/rs17132306

Resosudarmo, B. P., Rezki, J. F., & Effendi, Y. (2023). Prospects of energy transition in Indonesia. Bulletin of Indonesian Economic Studies, 59(2), 149-177. https://doi.org/10.1080/00074918.2023.2238336

Safari, V., Kamkari, B., Hooman, K., & Khodadadi, J. M. (2022). Sensitivity analysis of design parameters for melting process of lauric acid in the vertically and horizontally oriented rectangular thermal storage units. Energy, 255, 124521. https://doi.org/10.1016/j.energy.2022.124521

Saffiudeen, M. F., Swaminathan, V., & Fathi, A. W. (2026). Comprehensive Review on Failure Mechanisms in Heat Exchanger Tubes: Insights into Material Degradation, Corrosion, and Design Flaws. Journal of Bio-and Tribo-Corrosion, 12(2), 85. https://doi.org/10.1007/s40735-026-01146-5

Sahin, H., Solomon, A. A., Aghahosseini, A., & Breyer, C. (2026). Uneven distribution of natural energy resources impacts on systemwide energy return on investment. Earth's Future, 14(1), e2025EF006183. https://doi.org/10.1029/2025EF006183

Shahzad, S., & Jasińska, E. (2024). Renewable revolution: A review of strategic flexibility in future power systems. Sustainability, 16(13), 5454. https://doi.org/10.3390/su16135454

Smarte Anekwe, I. M., Akpasi, S. O., Mkhize, M. M., Zhou, H., Moyo, R. T., & Gaza, L. (2024). Renewable energy investments in South Africa: Potentials and challenges for a sustainable transition-a review. Science Progress, 107(2), 00368504241237347. https://doi.org/10.1177/00368504241237347

Srivastava, A. N., Sikarwar, V. S., Bisen, D., Fathi, J., Maslani, A., Lopez Nino, B. N., ... & Buryi, M. (2025). E-waste unplugged: Reviewing impacts, valorization strategies and regulatory frontiers for efficient E-waste management. Processes, 13(7), 2014. https://doi.org/10.3390/pr13072014

Veeraraghavan, G., Subramaniam, P., & Rajesh, M. (2025). Computational and experimental studies on the thermal performance of synthesized composite nanofluid in rectangular microchannel heat sink. Results in Engineering, 25, 103687. https://doi.org/10.1016/j.rineng.2024.103687

Wang, F., Li, P., Gai, L., Chen, Y., Zhu, B., Chen, X., ... & Wang, B. (2024). Enhancing the efficiency of power generation through the utilisation of LNG cold energy by a dual-fluid condensation rankine cycle system. Energy, 305, 132113. https://doi.org/10.3390/en18061415

Wang, Q., Yang, C., He, J., Zuo, X., Shi, Z., & Wang, P. (2025, July). Analysis of Factors Affecting Plant Power Consumption Rate and Identification of Abnormal Data in Coal-Fired Power Plants. In 2025 4th International Conference on Smart Grids and Energy Systems (SGES) (pp. 171-178). IEEE. https://doi.org/10.1109/SGES66701.2025.11156091

Wasisto, H. W., & Wahjudi, A. (2024, May). Study of primary air ratio, coal fineness and excess air to produce boiler efficiency, NPHR and optimal NOx emissions in pulverized coal boiler 200 MW. In AIP Conference Proceedings (Vol. 2891, No. 1, p. 050013). AIP Publishing LLC. https://doi.org/10.1063/5.0201479

Wibowo, S., Kiono, B., & Windarta, J. (2023, May). Energy conservation opportunities in coal-fired power plant through detailed energy audit. In The 6th International Conference On Energy, Environment, Epidemiology And Information System (ICENIS) 2021: Topic of Energy, Environment, Epidemiology, and Information System (Vol. 2683, No. 1, p. 020006). AIP Publishing LLC.

Xie, B., Du, S., Wang, R., Kou, X., Jiang, J., & Li, C. (2024). Heat pump integrated with latent heat energy storage. Energy & Environmental Science, 17(19), 6943-6973. DOI https://doi.org/10.1039/D4EE02350A

Yudha, S. W., Tjahjono, B., & Longhurst, P. (2021). Stakeholders’ recount on the dynamics of Indonesia’s renewable energy sector. Energies, 14(10), 2762. https://doi.org/10.3390/en14102762

Zhang, H., Da, Y., Zhang, X., & Fan, J. L. (2021). The impacts of climate change on coal-fired power plants: evidence from China. Energy & Environmental Science, 14(9), 4890-4902. https://doi.org/10.1039/D1EE01475G

Zhang, Y., Yang, T., Zhou, H., Lyu, D., Zheng, W., & Li, X. (2023). A prognosis method for condenser fouling based on differential modeling. Energies, 16(16), 5961. https://doi.org/10.3390/en16165961

Published
2026-06-30
How to Cite
Nayaparana, H., Purwanto, P., & Kusdiyantini, E. (2026). The Effect of Cooling Water Inlet Emperature (CWIT) on Efficiency USC 1050 MW Steam Power Plant . Journal La Multiapp, 7(3), 620-641. https://doi.org/10.37899/journallamultiapp.v7i3.3296