Performance Characterization of a Hybrid PV-CSP-TES-PCM-SOEC System with Renewable Integration for Sustainable Hydrogen Production across Indian Climate Zones

J.S.D. Nandini; K.S. Reddy

doi:10.65582/gti.2026.014

Authors

J.S.D. Nandini Heat Transfer and Thermal Power Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India. https://orcid.org/0009-0001-2249-895X
K.S. Reddy Heat Transfer and Thermal Power Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India. https://orcid.org/0000-0003-0562-4042

DOI:

https://doi.org/10.65582/gti.2026.014

Keywords:

Green hydrogen, Solid oxide electrolysis cell (SOEC), Concentrated solar power, MgCl2 phase-change material, Thermal energy storage, Flexible SOEC scheduling, Photovoltaic (PV), Hybrid renewable energy system

Abstract

Continuous green hydrogen production from solar energy faces two fundamental challenges. Solar resources are inherently intermittent. At the same time, solid oxide electrolysis cells (SOECs) require a stable, high-temperature thermal input around the clock. This study proposes a hybrid photovoltaic-concentrated solar power-thermal energy storage-solid oxide electrolysis cell (PV-CSP-TES-SOEC) system. The system uses anhydrous magnesium chloride (MgCl₂) as a high-temperature phase-change material (melting point ≈ 714 °C; latent heat 452 kJ kg⁻¹). This material bridges overnight thermal energy deficits and enables uninterrupted SOEC operation without grid support. Five Indian climate zones were investigated - Jodhpur, Ladakh, Nagpur, Bengaluru, and Kochi, using a full 8760-hour hourly dynamic simulation with NSRDB SUNY TMY data, preceded by static sizing to establish baseline component requirements. Static sizing shows that PV area varies by 22% across sites, while CSP aperture varies by up to 55%. The required MgCl₂ mass ranges from 190 to 240 t under baseline conditions. After optimisation, the required PCM mass increases to 325.7-823.9 t. Nagpur requires the highest due to prolonged monsoon-related solar suppression. Under constant-load SOEC operation, hourly reliability reaches only 62.1 to 68.7%. Hydrogen output drops to 729-788 kg day⁻¹, which is 27-33% below the 1080 kg day⁻¹ target. This shortfall is caused entirely by TES depletion during pre-dawn hours. A three-period flexible scheduling strategy is introduced. The SOEC operates at 0.6× load at night, 1.0× during shoulder hours, and 1.5-1.8× during the solar peak. This strategy restores full hydrogen output and increases reliability to 95.1-95.7% across all five sites. This corresponds to an improvement of 26-34 percentage points compared to constant-load operation. The results demonstrate that demand-side scheduling optimisation, rather than infrastructure oversizing, is the decisive factor enabling near-continuous grid-independent solar hydrogen production across climatically diverse locations.

References

Acar C. and Dincer I., 2019. Review and evaluation of hydrogen production options for better environment. Journal of Cleaner Production, 218: 835–849. DOI: doi.org/10.1016/j.jclepro.2019.02.046.

Afroze S., 2023. Solar-powered water electrolysis using hybrid solid oxide electrochemical cell system. Energies, 16(23): 7794. DOI: doi.org/10.3390/en16237794.

Alva G., Liu L., Huang X. and Fang G., 2017. Thermal energy storage materials and systems for solar energy applications. Renewable and Sustainable Energy Reviews, 68: 693–706. DOI: doi.org/10.1016/j.rser.2016.10.021.

Azzaoui A. and Alami Merrouni A., 2025. Hybrid CSP-PV combination to enhance green hydrogen production in Morocco: solar technologies evaluation and techno-economic analysis. Processes, 13(3): 769. DOI: doi.org/10.3390/pr13030769.

Bhandari R., Trudewind C. A. and Zapp P., 2014. Life cycle assessment of hydrogen production via electrolysis: a review. Journal of Cleaner Production, 85: 151–163. DOI: doi.org/10.1016/j.jclepro.2013.07.048.

Brisse A., Schefold J. and Zahid M., 2008. High temperature water electrolysis in solid oxide cells. International Journal of Hydrogen Energy, 33(20): 5375–5382. DOI: doi.org/10.1016/j.ijhydene.2008.07.120.

Buttler A. and Spliethoff H., 2018. Current status of water electrolysis for energy storage, grid balancing and sector coupling via power-to-gas and power-to-liquids: a review. Renewable and Sustainable Energy Reviews, 82: 2440–2454. DOI: doi.org/10.1016/j.rser.2017.09.003.

Dincer I. and Acar C., 2015. Review and evaluation of hydrogen production methods for better sustainability. International Journal of Hydrogen Energy, 40(34): 11094–11111. DOI: doi.org/10.1016/j.ijhydene.2014.12.035.

Ebbesen S. D., Hogh J., Nielsen K. A., Nielsen J. U. and Mogensen M., 2011. Durable SOC stacks for production of hydrogen and synthesis gas by high temperature electrolysis. International Journal of Hydrogen Energy, 36(13): 7363–7373. DOI: doi.org/10.1016/j.ijhydene.2011.03.130.

El-Emam R. S. and Ozcan H., 2019. Comprehensive review on the techno-economics of sustainable large-scale clean hydrogen production. Journal of Cleaner Production, 220: 593–609. DOI: doi.org/10.1016/j.jclepro.2019.01.309.

Ernst M., Goodman G. and Muller B., 2019. Methodology for generating high time resolution typical meteorological year data for accurate photovoltaic energy yield modelling. Solar Energy, 181: 16–26. DOI: doi.org/10.1016/j.solener.2019.01.069.

Fallah Vostakola M., Ozcan H., El-Emam R. S. and Amini Horri B., 2023. Recent advances in high-temperature steam electrolysis with solid oxide electrolysers for green hydrogen production. Energies, 16(8): 3327. DOI: doi.org/10.3390/en16083327.

Farid M. M., Khudhair A. M., Razack S. A. K. and Al-Hallaj S., 2004. A review on phase change energy storage: materials and applications. Energy Conversion and Management, 45(9–10): 1597–1615. DOI: doi.org/10.1016/j.enconman.2003.09.015.

Fernandez-Garcia A., Zarza E., Valenzuela L. and Perez M., 2010. Parabolic-trough solar collectors and their applications. Renewable and Sustainable Energy Reviews, 14(7): 1695–1721. DOI: doi.org/10.1016/j.rser.2010.03.012.

Gallardo F. I., Ferrario A. M., Lamagna M., Bocci E., Garcia D. A. and Baeza-Jeria T. E., 2021. A techno-economic analysis of solar hydrogen production by electrolysis in north Chile and the case of exportation from Atacama Desert to Japan. International Journal of Hydrogen Energy, 46(26): 13709–13728. DOI: doi.org/10.1016/j.ijhydene.2020.09.245.

Glenk G. and Reichelstein S., 2019. Economics of converting renewable power to hydrogen. Nature Energy, 4(3): 216–222. DOI: doi.org/10.1038/s41560-019-0326-1.

Graves C., Ebbesen S. D., Mogensen M. and Lackner K. S., 2011. Sustainable hydrocarbon fuels by recycling CO₂ and H₂O with renewable or nuclear energy. Renewable and Sustainable Energy Reviews, 15(1): 1–23. DOI: doi.org/10.1016/j.rser.2010.07.014.

Green M. A., Hishikawa Y., Dunlop E. D., Levi D. H., Hohl-Ebinger J. and Ho-Baillie A. W. Y., 2018. Solar cell efficiency tables (version 52). Progress in Photovoltaics: Research and Applications, 26(7): 427–436. DOI: doi.org/10.1002/pip.3040.

Hermesmann M. and Muller T. E., 2022. Green, turquoise, blue, or grey? Environmentally friendly hydrogen production in transforming energy systems. Progress in Energy and Combustion Science, 90: 100996. DOI: doi.org/10.1016/j.pecs.2022.100996.

International Energy Agency (IEA), 2019. The future of hydrogen: seizing today’s opportunities. Paris: International Energy Agency. DOI: doi.org/10.1787/1e0514c4-en.

International Energy Agency (IEA), 2024. Global hydrogen review 2024. Paris: International Energy Agency. Available at https://www.iea.org/reports/global-hydrogen-review-2024 [Last accessed March 2026].

International Renewable Energy Agency (IRENA), 2020. Green hydrogen cost reduction: scaling up electrolysers to meet the 1.5 degrees C climate goal. Abu Dhabi: International Renewable Energy Agency. Available at https://www.irena.org/publications/2020/Dec/Green-hydrogen-cost-reduction [Last accessed March 2026].

Ishan P., Rajput P., Shukla A. K. and Gupta M. K., 2024. Dynamic modelling of hybrid solar PV-CSP integrated high-temperature electrolyser system for flexible hydrogen generation. Energy, 302: 125678.

Kakoulaki G., Kougias I., Taylor N., Dolci F., Moya J. and Jaeger-Waldau A., 2021. Green hydrogen in Europe: a regional assessment — substituting existing production with electrolysis powered by renewables. Energy Conversion and Management, 228: 113649. DOI: doi.org/10.1016/j.enconman.2020.113649.

Kalogirou S. A., 2014. Solar energy engineering: processes and systems. 2nd ed. Waltham, MA: Academic Press.

Kenisarin M. M., 2010. High-temperature phase change materials for thermal energy storage. Renewable and Sustainable Energy Reviews, 14(3): 955–970. DOI: doi.org/10.1016/j.rser.2009.11.011.

Kuravi S., Trahan J., Goswami D. Y., Rahman M. M. and Stefanakos E. K., 2013. Thermal energy storage technologies and systems for concentrating solar power plants. Progress in Energy and Combustion Science, 39(4): 285–319. DOI: doi.org/10.1016/j.pecs.2013.02.001.

Laguna-Bercero M. A., 2012. Recent advances in high temperature electrolysis using solid oxide fuel cells: a review. Journal of Power Sources, 203: 4–16. DOI: doi.org/10.1016/j.jpowsour.2011.12.019.

Lappalainen J., Hakkarainen E., Sihvonen T., Deb D. and Lappalainen K., 2019. Modelling the dynamic behaviour of a solar steam generator: part I — theoretical review and modelling methodology. Solar Energy, 193: 956–981. DOI: doi.org/10.1016/j.solener.2019.10.012.

Lund H., Andersen A. N., Østergaard P. A., Mathiesen B. V. and Connolly D., 2015. From electricity smart grids to smart energy systems: a market operation based approach and understanding. Energy, 92: 96–104. DOI: doi.org/10.1016/j.energy.2015.09.040.

Ma Z. and Martinek J., 2023. Integration of concentrating solar power with high-temperature electrolysis: techno-economic and operational assessment. NREL Technical Report NREL/TP-5500-87561. Golden, CO: National Renewable Energy Laboratory.

Mehrpooya M., Habibi R. and Ghorbani B., 2021. Thermochemical water splitting hydrogen production processes: a review. International Journal of Hydrogen Energy, 46(55): 27995–28022. DOI: doi.org/10.1016/j.ijhydene.2021.06.085.

Ministry of New and Renewable Energy (MNRE), 2023. National green hydrogen mission: strategic interventions for green hydrogen transition (SIGHT). New Delhi: Government of India.

Mukelabai M. D., Grima C., Patel R. and Sheratt R. M., 2024. Modelling and optimisation of renewable hydrogen systems: a systematic methodological review and machine learning integration. Energy and AI, 17: 100391. DOI: doi.org/10.1016/j.egyai.2024.100391.

Naeini M., Cotton J. S. and Adams T. A., 2022. An eco-technoeconomic analysis of hydrogen production using solid oxide electrolysis cells that accounts for long-term degradation. Frontiers in Energy Research, 10: 1015465. DOI: doi.org/10.3389/fenrg.2022.1015465.

Norman E. A., Maestre V. M., Ortiz A. and Ortiz I., 2024. Steam electrolysis for green hydrogen generation: state of the art and research perspective. Renewable and Sustainable Energy Reviews, 202: 114725. DOI: doi.org/10.1016/j.rser.2024.114725.

Osman A. I., Mehta N., Elgarahy A. M., Hefny M., Al-Hinai A., Al-Muhtaseb A. H. and Rooney D. W., 2022. Hydrogen production, storage, utilisation and environmental impacts: a review. Environmental Chemistry Letters, 20(1): 153–188. DOI: doi.org/10.1007/s10311-021-01322-8.

Patel M. T., Asadpour R., Khan M. R. and Alam M. A., 2023. Resource potential mapping of bifacial photovoltaic systems in India. iScience, 26(4): 106424. DOI: doi.org/10.1016/j.isci.2023.106424.

Pfenninger S., Hawkes A. and Keirstead J., 2014. Energy systems modelling for twenty-first century energy challenges. Renewable and Sustainable Energy Reviews, 33: 74–86. DOI: doi.org/10.1016/j.rser.2014.02.003.

Prieto C. and Cabeza L. F., 2019. Thermal energy storage with phase change materials in concentrated solar power plants: a review. Applied Energy, 254: 113333. DOI: doi.org/10.1016/j.apenergy.2019.113333.

Rashid A., Alnaimat F., Al Ghaferi A. and Mathew B., 2023. Hybrid solar PV-CSP configuration with solid oxide electrolyser and thermal energy storage for 24/7 hydrogen production. Energies, 16(11): 4532. DOI: doi.org/10.3390/en16114532.

Reksten A. H., Thomassen M. S., Moller-Holst S. and Sundseth K., 2022. Projecting the future cost of PEM and alkaline water electrolysers. International Journal of Hydrogen Energy, 47(90): 38106–38113. DOI: doi.org/10.1016/j.ijhydene.2022.08.306.

Riffat J. and Samaei S. R., 2026. Thermochemical energy storage for renewable grids: a critical review of materials, reactor architectures, and integration strategies. Research and Reviews in Sustainability, 2(1): 12–30.

Rosenstiel A., Monnerie N., Dersch J., Roeb M., Pitz-Paal R. and Sattler C., 2021. Electrochemical hydrogen production powered by PV/CSP hybrid power plants. Energies, 14(12): 3437. DOI: doi.org/10.3390/en14123437.

Saif A. G. H., Alquaity A. B. S. and Mokheimer E. M. A., 2025. Techno-economic analysis of green hydrogen production in Saudi Arabia. Energies, 18(1): 194. DOI: doi.org/10.3390/en18010194.

Schmidt O., Gambhir A., Staffell I., Hawkes A., Nelson J. and Few S., 2017. Future cost and performance of water electrolysis. International Journal of Hydrogen Energy, 42(52): 30470–30492. DOI: doi.org/10.1016/j.ijhydene.2017.10.045.

Schoots K., Ferioli F., Kramer G. J. and van der Zwaan B. C. C., 2008. Learning curves for hydrogen production technology. International Journal of Hydrogen Energy, 33(11): 2630–2645. DOI: doi.org/10.1016/j.ijhydene.2008.03.011.

Sengupta M., Xie Y., Lopez A., Habte A., Maclaurin G. and Shelby J., 2018. The National Solar Radiation Data Base (NSRDB). Renewable and Sustainable Energy Reviews, 89: 51–60. DOI: doi.org/10.1016/j.rser.2018.03.003.

Soni N. and Reddy K. S., 2024. Techno-economic assessment of concentrated solar power technologies integrated with thermal energy storage system for green hydrogen production. International Journal of Hydrogen Energy, 72: 1184–1203. DOI: doi.org/10.1016/j.ijhydene.2024.05.409.

Soni N. and Reddy K. S., 2025. Modelling and analysis of a distributed green hydrogen generation system integrating concentrating solar power with thermal energy storage. Renewable Energy, 241: 122274. DOI: doi.org/10.1016/j.renene.2024.122274.

Staffell I., Scamman D., Velazquez Abad A., Balcombe P., Dodds P. E., Ekins P., Shah N. and Ward K. R., 2019. The role of hydrogen and fuel cells in the global energy system. Energy and Environmental Science, 12(2): 463–491. DOI: doi.org/10.1039/C8EE01157E.

Tarkowski R., 2019. Underground hydrogen storage: characteristics and prospects. Renewable and Sustainable Energy Reviews, 105: 86–94. DOI: doi.org/10.1016/j.rser.2019.01.051.

Tofighi M. and Faegh M., 2022. Solar-aided solid oxide electrolysis system with thermal energy storage for continuous hydrogen production. International Journal of Hydrogen Energy, 47(48): 32867–32880. DOI: doi.org/10.1016/j.ijhydene.2022.07.192.

Vignarooban K., Xu X., Arvay A., Hsu K. and Kannan A. M., 2015. Heat transfer fluids for concentrating solar power systems. Applied Energy, 146: 383–396. DOI: doi.org/10.1016/j.apenergy.2015.01.125.

Xu B., Li P. and Chan C., 2015. Application of phase change materials for thermal energy storage in CSP plants. Applied Energy, 160: 286–307. DOI: doi.org/10.1016/j.apenergy.2015.09.016.

Zhang X., Liu M., Song J., Zhao Y. and Liu J., 2021. Flexible operation and efficiency enhancement of CSP plants using PCM. Applied Energy, 285: 116445. DOI: doi.org/10.1016/j.apenergy.2021.116445.

Zhang Y., Aydin D., Jarimi H. and Kutlu C., 2026. Review of recent developments in thermochemical energy storage materials and systems. Research and Reviews in Sustainability, 2(1): 103–124.

Zhao C. Y., Wu Z. G. and Li Y., 2014. Heat transfer enhancement for thermal energy storage using metal chloride PCMs. Renewable Energy, 69: 134–146. DOI: doi.org/10.1016/j.renene.2014.03.034.

Zhao Z., Chen K., Liu J., Zhao Y., Ye L., Song H., Yang J. and Wang C., 2020. Dynamic modelling of SOEC system. Renewable and Sustainable Energy Reviews, 132: 110032. DOI: doi.org/10.1016/j.rser.2020.110032.