Economic and environmental assessment of a concentrated solar power system using sand as a heat transfer medium

Hany Al-Ansary; Abdulaziz Al-Shehri; Shaker Alaqel; Eldwin Djajadiwinata; Rageh S. Saeed; Nader S. Saleh; Abdelrahman El-Leathy; Syed Danish; Zeyad Al-Suhaibani

Authors

Hany Al-Ansary Department of Mechanical Engineering, College of Engineering, King Saud University, Riyadh, Saudi Arabia https://orcid.org/0000-0002-5419-3501
Abdulaziz Al-Shehri Department of Research and Development, Saudi Electricity Company, Riyadh, Saudi Arabia https://orcid.org/0009-0000-0027-3226
Shaker Alaqel Department of Mechanical Engineering, College of Engineering, King Saud University, Riyadh, Saudi Arabia https://orcid.org/0000-0002-5327-3059
Eldwin Djajadiwinata Department of Mechanical Engineering, College of Engineering, King Saud University, Riyadh, Saudi Arabia https://orcid.org/0000-0001-6777-7824
Rageh S. Saeed Department of Mechanical Engineering, College of Engineering, King Saud University, Riyadh, Saudi Arabia https://orcid.org/0000-0001-7574-2891
Nader S. Saleh Department of Mechanical Engineering, College of Engineering, King Saud University, Riyadh, Saudi Arabia https://orcid.org/0000-0001-8189-2837
Abdelrahman El-Leathy Department of Mechanical Engineering, College of Engineering, King Saud University, Riyadh, Saudi Arabia https://orcid.org/0000-0001-9344-3713
Syed Danish Sustainable Energy Technologies Centre, King Saud University, Riyadh, Saudi Arabia https://orcid.org/0000-0002-8483-4920
Zeyad Al-Suhaibani Department of Mechanical Engineering, College of Engineering, King Saud University, Riyadh, Saudi Arabia https://orcid.org/0009-0006-4123-6425

Keywords:

Concentrated solar power, Sand-based heat transfer, Fuel consumption reduction, Carbon dioxide emissions, Thermal battery storage, Heliostat efficiency, Renewable energy

Abstract

Concentrated solar power (CSP) systems offer a promising pathway to reduce fossil fuel dependence, particularly in regions with abundant sunlight. This study evaluates the economic, environmental, and fuel-saving benefits of a CSP system using locally sourced sand as a heat transfer medium. The system integrates a sand–air heat exchanger, a microturbine (100 kWe), and a 300 kW thermal battery. Tested during peak solar hours, the turbine achieved 39.5% thermal efficiency using heliostats to concentrate solar energy and heat sand particles, transferring thermal energy to drive the turbine. Operational data show a 20% reduction in fuel consumption and carbon dioxide emissions, resulting in significant financial reductions and environmental benefits. The thermal battery enables continued operation during cloudy periods or nighttime by storing excess heat, further enhancing fuel efficiency and emission reductions. Reaching technology readiness level 7 in 2018, the prototype demonstrates viability for regions with high direct normal irradiation, such as Saudi Arabia. Key performance factors include heliostat quality, heat exchanger efficiency, and sand thermal properties. Despite challenges like heliostat degradation since 2009, the system shows scalability potential. Solar contribution could reach 80% with an optimized design, amplifying economic and environmental gains. The study highlights the promise of sand-based CSP systems in reducing fossil fuel reliance and supporting global sustainability goals. Future improvements should focus on enhancing heliostat reflectivity, refining heat exchanger design, and selecting sand with better thermal stability. These advancements could pave the way for cost-effective, renewable energy solutions in desert regions rich in solar and sand resources.