Concentrated Solar Power Research Articles

There is an urgent need to reduce greenhouse gas emissions, particularly carbon dioxide (CO2). Currently, numerous research initiatives are underway to develop CO2 Capture and Storage (CCS) technologies aiming for net-zero emissions, especially in sectors that are difficult to decarbonize, such as fossil fuel power generation. Integrating solar thermal energy into CO2 capture facilities (CCFs) for fossil fuel-based power plants offers a promising approach to reduce the high operational costs associated with CO2 capture processes. However, a comprehensive systematic review focusing on the integration of solar thermal energy with CCFs in fossil fuel power generation is currently lacking. To address this gap, this study systematically evaluates the technological frameworks involved, including (a) various generation technologies such as coal-fired Rankine cycle plants, natural gas combined cycle plants, and cogeneration units; (b) concentrated solar power (CSP) technologies, including parabolic trough collectors, linear Fresnel reflectors, solar power towers, and Stirling dish systems; and (c) post-combustion CO2 capture systems. Additionally, this research analyzes relevant projects, patents, and scholarly publications from the past 25 years that explore the coupling of CSP technologies with fossil fuel power plants and post-combustion CO2 capture systems. This literature review encompasses diverse methodologies, such as innovative patents, conceptual models, evaluations of solar collector performances, thermal integration optimization, and various system configurations. It also investigates technical advancements aimed at improving efficiency, reliability, and flexibility of fossil fuel power plants while mitigating the inherent challenges of CO2 capture. Beyond the energy-focused aspects, we explore complementary circular economy strategies—such as by-product valorization and material substitution in sectors like mining, cement, and steel manufacturing—that can reduce embodied emissions and enhance the overall system benefits of solar-assisted CO2 capture. The review employs a bibliometric approach using digital tools including Publish or Perish, Mendeley, and VOSviewer to systematically analyze the scholarly landscape.

Abstract This paper focuses on the expansion train designed for the Compressed Air Energy Storage (CAES) concept under development in the EU-funded ASTERIx-CAESar project. The system integrates concentrated solar thermal energy from a high-temperature (800°C) volumetric central-receiver into a hybrid storage configuration, combining Low-Temperature Thermal Energy Storage (LT-TES) with Compressed Air Storage (CAS) and High-Temperature Thermal Energy Storage (HT-TES). Electricity from the grid powers compressors during low-price periods, storing compressed air and recovering compression heat in LT-TES. Solar heat is stored in HT-TES. During discharge, preheaters and reheaters supply stored energy to the expansion train. Residual energy in the exhaust of the low-pressure turbine reduces round-trip efficiency; therefore, a bottoming Waste Heat Recovery (WHR) unit based on Organic Rankine Cycle (ORC) technology is assessed. Multiple air-cooled configurations are modelled for Expander Exit Temperatures (EET) of 300-600°C, using organic fluids and steam in subcritical, transcritical and supercritical layouts. Scale effects on expander type (screw or axial) and isentropic efficiency are considered for capacities from 1 to 100 MWe. A multi-objective optimisation of the bottoming cycle considers technical and economic aspects to maximise efficiency and heat recovery by adjusting vapour generator pressure/temperature. A global optimisation of the expansion train identifies the optimal cycle configuration for each EET and scale, integrating the WHR system with a two-stage turbine. Recommendations to improve CAES system efficiency are provided.

Experimental study on the gasification characteristics of biomass pyrolysis semi-coke driven by concentrated solar energy

A compact medium-temperature copper–water looped heat pipe for high concentrated solar thermal energy utilization

Energy characteristics of integrated waste gasification and solar thermal power systems via diverse coupling paths

High-entropy alloys (HEAs) have garnered significant attention due to their exceptional properties, such as high strength, hardness, corrosion resistance, and excellent formability, which present promising opportunities for energy-related applications. This study successfully synthesized a Ti-doped AlCrFeNiCu high-entropy alloy (HEA) using the laser additive manufacturing (LAM) technique, with potential applications in energy materials. The effects of Ti doping (1 at% and 3 at%) on the mechanical properties and microstructural development of the AlCrFeNiCu HEA were systematically examined. Microstructural analysis using scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS) identified a dual-phase structure comprising BCC and FCC solid solutions. An Instron universal testing machine and Vickers microhardness (HVN) testing were utilized to evaluate mechanical properties. The findings indicated that although compressive strength diminished with elevated Ti content, Ti enhanced the microhardness of the alloy. The findings indicate the potential applications of Ti-doped AlCrFeNi Cu HEAs in energy sectors, such as components for concentrated solar power systems, nuclear reactors, and advanced gas turbines, which require materials capable of withstanding elevated temperatures, mechanical stress, and corrosive environments. The tailored mechanical and microstructural properties of this HEA position it as a viable candidate for enhancing the longevity and efficiency of energy systems operating under challenging conditions.

ABSTRACT The growing demand for low‐cost, high‐performance thermal energy storage (TES) materials has prompted interest in repurposing metallurgical slags in concentrated solar power (CSP) systems. This review critically evaluates the potential of various steel, copper, and aluminum slags as high‐temperature TES media in packed‐bed configurations. Emphasis is placed on the thermophysical properties of steel slags, for example, with reported thermal conductivities ranging from 1.6 to 1.9 W/m K and specific heat capacities of up to 1.5 J/g K, making them competitive with conventional materials, such as molten salts. The review also explores numerical modeling approaches such as the Schumann model, local thermal non‐equilibrium (LTNE), and continuous solid‐phase frameworks to capture heat transfer behavior in slag‐based TES systems. Additionally, system‐level integration strategies, particularly direct and indirect packed‐bed designs, are compared to conventional two‐tank molten salt systems in terms of performance, cost, and environmental benefits. Notably, steel slags offer thermal stability above 1000°C, economic savings of up to 40% over commercial fillers, and significant CO 2 reductions through circular material reuse. Case studies and simulations validate slag's long‐term performance and scalability in CSP and industrial waste heat recovery applications. The review identifies research gaps in slag characterization, compatibility with heat transfer fluids, and modeling fidelity. This work contributes a comprehensive roadmap for advancing slag‐based TES technologies, providing insights for research in designing next‐generation, cost‐effective CSP systems.

Multi-methods cooling strategies for concentrated solar power (CSP) plants: technologies, challenges, and opportunities

Abstract Assessing the solar energy potential in the MENA/Mediterranean regions is of paramount importance, especially considering the environmental and economic benefits of solar energy sources. By examining the potential specific to these regions, we can provide valuable insights into the feasibility and potential for solar energy development, contributing to the overall renewable energy assessment and development. This research provides a granular assessment of solar energy potential across the MENA and Mediterranean regions by developing a solar potential zoning framework based on advanced clustering techniques applied to NASA POWER data. Our analysis of Global Horizontal Irradiance (GHI) delineated eight distinct zones, revealing a significant spatial gradient in solar resource availability. Annual average GHI values range from 4.57 kWh/m 2 /day in Zone 4 to 6.46 kWh/m 2 /day in Zone 8. These GHI levels correspond to photovoltaic (PV) specific yields of 1,334 kWh/kWp/year and 1,886 kWh/kWp/year, respectively, with high-potential zones (2, 3, 6, and 8) exhibiting yields above 1,730 kWh/kWp/year, highlighting their economic attractiveness for PV deployment. Analysis of Direct Normal Irradiance (DNI) identified nine zones, with the highest DNI levels observed in Zones 4, 1, and 8, exceeding 6.3 kWh/m 2 /day, which are particularly suitable for Concentrated Solar Power (CSP) technologies, offering annual generation per unit area up to 31% higher than lower DNI regions. The developed zoning maps and quantitative findings for strategic planning, guiding investment and policy towards maximizing solar energy adoption and contributing to the region's energy security and sustainability goals.

With the rapid development of solar thermal power generation technology, the structural stability of the dish solar concentrator system under complex wind environments has become a critical limiting factor for its large-scale application. This study investigates the flow field distribution and structural response under fluctuating wind loads using computational fluid dynamics (CFD). A three-dimensional model was developed and simulated in ANSYS Fluent under varying wind angles and speed cycles. The results indicate that changes in the concentrator’s orientation significantly influence the airflow field, with the most adverse effects observed at low elevation angles (0°) and an azimuth angle of 60°. Short-period wind loads (T = 25 s) exacerbate transient impact effects of lift forces and overturning moments, markedly increasing structural fatigue risks. Long-period winds (T = 50 s) amplify cumulative drag forces and tilting moments (e.g., peak drag of −73.9 kN at β = 0°). Key parameters for wind-resistant design are identified, including critical angles and period-dependent load characteristics.

The ocean, as one of the largest thermal energy storage bodies on earth, has great potential as a thermal-electric energy reserve. Application of the relatively fixed-temperature ocean as the heat sink, and using concentrated solar energy as the heat source, one may construct a mobile power station on the ocean’s surface. However, a traditional solar-based heat source requires a large footprint to concentrate the light beam, resulting in bulky parabolic dishes, which are impractical under ocean engineering scenarios. For buoy-sized applications, the small form factor of the energy collector can only achieve limited temperature differential, and its energy quality is deemed to be unusable by traditional spring-loaded free piston Stirling engines. Facing these challenges, a low-temperature differential free piston Stirling engine is presented. The engine features a large displacer piston (ϕ136, 5 mm thick) made of corrugated board, and an aluminum power piston (ϕ10). Permanent magnets embedded in both pistons couple them through magnetic attraction rather than a mechanical spring. This magnetic “spring” delivers an inverse-exponential force–distance relation: weak attraction at large separations minimizes damping, while strong attraction at small separations efficiently transfers kinetic energy from the displacer to the power piston. Engine dynamics are captured by a lumped-parameter model implemented in Simulink, with key magnetic parameters extracted from finite-element analysis. Initial results have shown that the laboratory prototype can operate continuously across heater-to-cooler temperature differences of 58–84 K, sustaining flywheel speeds of 258–324 RPM.

Reliable cost projection data is critical for energy system modelling, guiding policy and investment decisions that underpin the global energy transition. In this work, we compile and standardise a broad dataset from over 110 existing regional and global studies to provide an organised and spatio-temporally granular dataset of cost projections for major clean energy technologies. The dataset covers Capital Expenditures (CAPEX) and Levelised Costs of Electricity or Hydrogen (LCOE or LCOH) for utility-scale and rooftop photovoltaics, onshore and offshore wind power, grid-scale Li-ion batteries, concentrated solar thermal power, and large-scale alkaline and PEM electrolysers. The data span national, continental, and global scales, with annual granularity through 2050 and metadata for source type and region. Values under various scenarios are provided to enable risk and uncertainty assessments. This resource supports scenario modelling, investment planning, policy design, and benchmarking in the context of decarbonisation pathways. While the data are drawn entirely from existing sources, the novelty lies in the structured harmonisation, metadata processing, and comprehensive coverage, making it suitable for techno-economic evaluation and robust energy system modelling.

Clinker, constituting approximately 72% of cement's composition, is produced through an energy-intensive process that significantly contributes to CO2 emissions. This study explores the integration of a solar calciner into the Chilean cement industry, particularly in the Antofagasta region, which is characterized by high solar energy irradiation, with an annual DNI of 3,250 kWh/m2. This region also accounts for approximately 30% of the country's cement sector energy consumption. In this context, this study evaluates two Concentrated Solar Thermal (CST) scenarios: the Top of Tower (TT) system and the Beam-down (BD) system, assessing their technical and economic feasibility for reducing CO2 emissions in the calcination process. The findings suggest that both CST systems could substantially reduce CO2 emissions in the calciner. However, economic feasibility remains a challenge, primarily due to the low cost of coal, which is the main fuel in the Chilean cement industry. Additionally, the efficiency of the solar calciner is found to be crucial for achieving maximum emission reductions, for the scalability of the technology, and for its future adoption in Chile's cement industry. Although the Levelized Cost of Heat (LCOH) for the proposed plants is currently higher than the coal-fired calciners in which is produced about 90% of current clinker production in Chile, potential reductions in heliostat costs, coupled with an increase in carbon taxes beyond the current value of 5 USD/tCO2, could significantly improve the economic viability of CST plants in Chile's cement industry.

Abstract Supercritical Carbon Dioxide (sCO2) power cycles have emerged as a promising technology for a variety of applications involving transient operations. These include load-following power plants and systems operating with intermittent heat inputs, such as waste heat recovery, CO2 batteries, and solar thermal power generation. This paper explores dynamic response and control system design of a 5 MW simple recuperated sCO2 Brayton cycle, focusing on inventory and turbine bypass control strategies. A linear control system for regulating inventory tank valves is analyzed through step-response testing, revealing rapid response characteristics of inventory rejection, while non-minimum phase behavior of inventory injection. Transfer function-based representation is proposed to aid control system design and analysis. Design of a Proportional-Integral (PI) controller is carried out using classical Bode plots technique. Although the PI controller improves tracking accuracy, its performance degrades at high ramp rates, and due to plant gain reduction and non-minimum phase behavior. Transient thermal analysis of the recuperator, performed a posteriori step using Flownex, quantifies time-varying heat duties and cycle efficiency. During part-load transients, small terminal temperature variations result in nearly constant wall temperature profiles, making the energy stored in the heat exchanger walls orders of magnitude smaller than the convective heat transfer rates. Turbine bypass control is demonstrated to serve as an alternative, offering first-order dynamics and faster ramp rates. Overall, the study demonstrates the efficacy of simple PI controllers for load regulation in sCO2 Brayton cycles.

In concentrated solar power (CSP) systems, structural materials face severe corrosion challenges induced by molten chlorides, with the corrosion severity being highly dependent on the salt composition. This study systematically compares the corrosion behavior of two representative superalloys, Inconel 625 and SS321, in binary NaCl–KCl and ternary MgCl2–NaCl–KCl molten salts at 700 °C. The corrosion products and microstructural features were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with energy-dispersive spectroscopy (EDS), and electron backscatter diffraction (EBSD), in combination with static exposure tests to elucidate the underlying mechanisms. The results show that in NaCl–KCl molten salts, both alloys primarily form Cr2O3 as the protective product. However, the corrosion scale of SS321 is porous, whereas Inconel 625 develops a dense NiCr2O4 inner layer, exhibiting superior corrosion resistance. In the MgCl2–NaCl-KCl molten salt system, Cr2O3 is replaced by a dense MgO layer forms on Inconel 625, coupled with Mo surface enrichment, which significantly inhibits Cr depletion and leads to a notably reduced corrosion rate relative to the binary salt. In contrast, the transformation of Cr2O3 on SS321 into porous MgCr2O4 exacerbates intergranular corrosion, resulting in a substantial degradation of corrosion resistance. This study elucidates the distinct corrosion pathways and mechanisms of different alloys in binary and ternary chloride salts, providing important guidance for the selection of molten salt compositions and corrosion-resistant structural materials in CSP applications.

This paper presents the design, construction, and preliminary testing of an innovative skip-hoist particle lift (PL) integrated with a multi-layered cylindrical thermal energy storage (TES) system for particle-based concentrated solar power (CSP) applications. The skip-hoist PL, constructed with stainless steel for high-temperature compatibility, was seamlessly integrated with two TES bins on a 22-m concrete tower. Preliminary testing at ambient temperature confirmed the system’s operational feasibility, paving the way for high-temperature testing and the proposed 1.3 MWe pre-commercial scale-up in Waad Al-Shamal, Saudi Arabia.

The integration of solar energy into hydrogen fuel production marks a key step towards sustainable energy. This study, which is part of a Marie Skłodowska-Curie Action called “TOPCSP”, aims to optimize the design of a concentrated solar power system tailored for high-temperature applications such as thermochemical cycles for hydrogen production. The system features a point-focus tower with compound parabolic concentrators as secondary concentrator to maximize solar radiation capture and to minimize receiver thermal losses, enhancing the efficiency of the solar-to-fuel conversion. Hydrogen is produced through a two-step thermochemical cycle using non-stoichiometric ceria, designed for high efficiency and scalability. Through theoretical modeling and simulations, this work presents an optimal optical configuration that boosts hydrogen production rates and reduces overall system costs.

Abstract Chloride salts are used as the heat transfer (HT) media for the third‐generation concentrated solar power (CSP). Challenges such as localized high‐temperature and uneven wall temperature within the absorber tube (AT) persist. Furthermore, the HT of mixed convection (MC) for molten salt is different from that for common fluid. To address these issues, an AT featuring turbulent MC is proposed and numerically analyzed. Furthermore, the performance of AT is evaluated under various operational parameters. Results indicate that the secondary flow (SF) induced by buoyancy force (BF) generates two vortices, enhancing salt mixing and HT. Consequently, there is a significant improvement in temperature uniformity, accompanied by a substantial reduction in the maximum temperature. Compared to forced convection (FC), the maximum temperature as well as temperature gradient for MC is reduced by up to 242.73 K. Additionally, there is an increase of 3.57–16.76% in the Nusselt number and a 5.98%–30.07% increase in the friction factor. The thermal performance factor (TPF) ranges from 1.016 to 1.070. Moreover, the maximum reduction in the entropy generation rate (EGR) is 16.52%, and the highest enhancement in exergy efficiency (EE) reaches 4.68%. This study provides practical insights for the development of more efficient and secure chloride salt AT.

This paper develops novel robust de novo programming models to accurately select optimal locations for concentrated solar power (CSP) plants under high levels of uncertainty. The CSP selection problem is a typical uncertain multi-objective decision-making (MODM) optimal design challenge that involves conflicting environmental, societal, and economic criteria. This paper makes the following contributions: (i) it develops robust counterparts to the conventional de novo programming (DNP) model and its meta-goal programming solution procedure to address a wide range of decision-making problems under conditions of uncertainty, (ii) it proposes a robust revised multi-choice DNP model, and (iii) it contributes to ongoing debates on sustainable development and clean energy transitions by identifying optimal locations for CSP plants in Morocco. The proposed robust methodologies provide decision-makers with increased flexibility for addressing uncertainty in MODM problems, allowing them to express their level of conservatism and preferences by setting priority weights, defining aspiration levels, and merging original explicit goals into meta-goals. Finally, the hypothetical application illustrates the effectiveness of the proposed formulations and demonstrates that they can assist decision-makers in identifying the optimal locations for CSP plants in Morocco under high levels of uncertainty.

Performance evaluation of natural draft dry cooling towers and pre-cooled natural draft dry cooling towers in concentrated solar power plants