This page has only limited features, please log in for full access.

Dr. Cristina Prieto
Head of Innovation, Abengoa Energia S.A, 41014 Seville, Spain

Basic Info

Basic Info is private.

Research Keywords & Expertise

0 Hybridization
0 Renewable Energy
0 thermal batteries
0 Thermal energy storage in the energy market
0 Concentrated solar plants

Fingerprints

Thermal energy storage in the energy market
Concentrated solar plants

Honors and Awards

The user has no records in this section


Career Timeline

The user has no records in this section.


Short Biography

The user biography is not available.
Following
Followers
Co Authors
The list of users this user is following is empty.
Following: 0 users

Feed

Journal article
Published: 28 June 2021 in Energies
Reads 0
Downloads 0

Steam accumulation is one of the most effective ways of thermal energy storage (TES) for the solar thermal energy (STE) industry. However, the steam accumulator concept is penalized by a bad relationship between the volume and the energy stored; moreover, its discharge process shows a decline in pressure, failing to reach nominal conditions in the turbine. From the economic point of view, between 60% and 70% of the cost of a steam accumulator TES is that of the pressure vessel tanks (defined as US$/kWhth). Since the current trend is based on increasing hours of storage in order to improve dispatchability levels in solar plants, the possibility of cost reduction is directly related to the cost of the material of pressure vessels, which is a market price. Therefore, in the present paper, a new design for steam accumulation is presented, focusing on innovative materials developed specifically for this purpose: two special concretes that compose the accumulation tank wall. Study of dosages, selection of materials and, finally, scale up on-field tests for their proper integration, fabrication and construction in prototype are the pillars of this new steam accumulation tank. Establishing clear and precise requirements and instructions for successful tank construction is necessary due to the highly sensitive and variable nature of those new concrete formulations.

ACS Style

Cristina Prieto; David Pérez Osorio; Edouard Gonzalez-Roubaud; Sonia Fereres; Luisa Cabeza. Advanced Concrete Steam Accumulation Tanks for Energy Storage for Solar Thermal Electricity. Energies 2021, 14, 3896 .

AMA Style

Cristina Prieto, David Pérez Osorio, Edouard Gonzalez-Roubaud, Sonia Fereres, Luisa Cabeza. Advanced Concrete Steam Accumulation Tanks for Energy Storage for Solar Thermal Electricity. Energies. 2021; 14 (13):3896.

Chicago/Turabian Style

Cristina Prieto; David Pérez Osorio; Edouard Gonzalez-Roubaud; Sonia Fereres; Luisa Cabeza. 2021. "Advanced Concrete Steam Accumulation Tanks for Energy Storage for Solar Thermal Electricity." Energies 14, no. 13: 3896.

Short communication
Published: 10 June 2021 in Journal of Energy Storage
Reads 0
Downloads 0

This study evaluates the proposal of a concrete storage tank as molten salt container, for concentrating solar power applications. A characterization of the thermal and mechanical properties including compression resistance, density, thermal conductivity and chemical degradation were evaluated in a pilot plant storage tank in contact with solar salt (60%NaNO3 + 40%KNO3) during 120 hours at 565°C. XRD and SEM analysis were carried out after the molten salt test, observing a penetration of salts in the concrete about 14.5 cm. The chemical and mechanical results in the concrete showed a good behaviour and resistance after the exposure test. Nevertheless, the presence of molten salt in the concrete changed its thermal properties, increasing the density and the thermal conductivity in the concrete zones closer to the molten salt reservoir.

ACS Style

Cristina Prieto; Angel G. Fernández; David Pérez-Osorio; Luisa F. Cabeza. Thermal and mechanical degradation assessment in refractory concrete as thermal energy storage container material in concentrated solar plants. Journal of Energy Storage 2021, 40, 102790 .

AMA Style

Cristina Prieto, Angel G. Fernández, David Pérez-Osorio, Luisa F. Cabeza. Thermal and mechanical degradation assessment in refractory concrete as thermal energy storage container material in concentrated solar plants. Journal of Energy Storage. 2021; 40 ():102790.

Chicago/Turabian Style

Cristina Prieto; Angel G. Fernández; David Pérez-Osorio; Luisa F. Cabeza. 2021. "Thermal and mechanical degradation assessment in refractory concrete as thermal energy storage container material in concentrated solar plants." Journal of Energy Storage 40, no. : 102790.

Journal article
Published: 08 May 2021 in Renewable Energy
Reads 0
Downloads 0

The circular economy can be promoted as a solution to support the sustainability market position of renewable energy systems. To design a circular and sustainable system, a structured approach is needed. The present study develops a methodology framework for sustainable circular system design (SCSD), aiming to assess thermal energy storage (TES) technologies from a sustainable perspective. To this end, a composite indicator, namely, environmental sustainability and circularity indicator (ESC) is provided. This indicator combines the environmental impacts of the TES system via the conduction of a life cycle assessment and its circulatory performance using the product-level material circularity indicator (MCI). The developed methodology is applied to a case study of high-temperature TES using molten salts as a part of a concentrated solar power plant. The SCSD embraces the analysis for the most relevant processes through proposing different ecological scenarios including, increasing the recycling rates (Modest Scenario), increasing the reuse rates (Medium Scenario), and a combination of both (Optimistic scenario). The circularity analysis showed that for the Modest, Medium and optimistic scenarios, the MCI moves from 20.6% for the current situation to 30.3%, 38.6%, and 46.4%, respectively. Accordingly, the optimistic scenario showed the most environmentally sustainable and circular scenario with ESC of 7.89%, whereas the Modest and Medium scenarios exhibited ESCs of 1.20% and 2.16%, respectively. A major obstacle for substantial improvement of the circulatory and ESC is the high share of unrecyclable molten salts in the system and therefore, any effort to improve the circulatory and the environmental benefits of this system can be reached by using more environmentally friendly alternative materials. The study concludes that the integration of reusing and recycling at the initial design should be sought in order to achieve a more environmentally sustainable and circular outcome.

ACS Style

Mohamed Hany Abokersh; Masoud Norouzi; Dieter Boer; Luisa F. Cabeza; Gemma Casa; Cristina Prieto; Laureano Jiménez; Manel Vallès. A framework for sustainable evaluation of thermal energy storage in circular economy. Renewable Energy 2021, 175, 686 -701.

AMA Style

Mohamed Hany Abokersh, Masoud Norouzi, Dieter Boer, Luisa F. Cabeza, Gemma Casa, Cristina Prieto, Laureano Jiménez, Manel Vallès. A framework for sustainable evaluation of thermal energy storage in circular economy. Renewable Energy. 2021; 175 ():686-701.

Chicago/Turabian Style

Mohamed Hany Abokersh; Masoud Norouzi; Dieter Boer; Luisa F. Cabeza; Gemma Casa; Cristina Prieto; Laureano Jiménez; Manel Vallès. 2021. "A framework for sustainable evaluation of thermal energy storage in circular economy." Renewable Energy 175, no. : 686-701.

Journal article
Published: 25 March 2021 in Sustainability
Reads 0
Downloads 0

Despite the big deployment of concentrating solar power (CSP) plants, their environmental evaluation is still a pending issue. In this paper, a detailed life cycle assessment (LCA) of a CSP tower plant with molten salts storage in a baseload configuration is carried out and compared with a reference CSP plant without storage. Results show that the plant with storage has a lower environmental impact due to the lower operational impact. The dependence on grid electricity in a CSP tower plant without storage increases its operation stage impact. The impact of the manufacturing and disposal stage is similar in both plants. When analyzed in detail, the solar field system and the thermal energy storage (TES) and heat transfer fluid (HTF) systems are the ones with higher impact. Within the storage system, the molten salts are those with higher impact. Therefore, in this study the impact of the origin of the salts is evaluated, showing that when the salts come from mines their impact is lower than when they are synthetized. Results show that storage is a key element for CSP plants not only to ensure dispatchability but also to reduce their environmental impact.

ACS Style

Gemma Gasa; Anton Lopez-Roman; Cristina Prieto; Luisa Cabeza. Life Cycle Assessment (LCA) of a Concentrating Solar Power (CSP) Plant in Tower Configuration with and without Thermal Energy Storage (TES). Sustainability 2021, 13, 3672 .

AMA Style

Gemma Gasa, Anton Lopez-Roman, Cristina Prieto, Luisa Cabeza. Life Cycle Assessment (LCA) of a Concentrating Solar Power (CSP) Plant in Tower Configuration with and without Thermal Energy Storage (TES). Sustainability. 2021; 13 (7):3672.

Chicago/Turabian Style

Gemma Gasa; Anton Lopez-Roman; Cristina Prieto; Luisa Cabeza. 2021. "Life Cycle Assessment (LCA) of a Concentrating Solar Power (CSP) Plant in Tower Configuration with and without Thermal Energy Storage (TES)." Sustainability 13, no. 7: 3672.

Journal article
Published: 26 February 2021 in Molecules
Reads 0
Downloads 0

The high intermittency of solar energy is still a challenge yet to be overcome. The use of thermal storage has proven to be a good option, with phase change materials (PCM) as very promising candidates. Nevertheless, PCM compounds have typically poor thermal conductivity, reducing their attractiveness for commercial uses. This paper demonstrates the viability of increasing the PCM effective thermal conductivity to industrial required values (around 4 W/m·K) by using metal wool infiltrated into the resin under vacuum conditions. To achieve this result, the authors used an inert resin, decoupling the specific PCM material selection from the enhancement effect of the metal wools. To ensure proper behavior of the metal wool under standard industrial environments at a broad range of temperatures, a set of analyses were performed at high temperatures and an inert atmosphere, presenting a thorough analysis of the obtained results.

ACS Style

Cristina Prieto; Anton Lopez-Roman; Noelia Martínez; Josep Morera; Luisa Cabeza. Improvement of Phase Change Materials (PCM) Used for Solar Process Heat Applications. Molecules 2021, 26, 1260 .

AMA Style

Cristina Prieto, Anton Lopez-Roman, Noelia Martínez, Josep Morera, Luisa Cabeza. Improvement of Phase Change Materials (PCM) Used for Solar Process Heat Applications. Molecules. 2021; 26 (5):1260.

Chicago/Turabian Style

Cristina Prieto; Anton Lopez-Roman; Noelia Martínez; Josep Morera; Luisa Cabeza. 2021. "Improvement of Phase Change Materials (PCM) Used for Solar Process Heat Applications." Molecules 26, no. 5: 1260.

Journal article
Published: 01 October 2020 in Journal of Energy Storage
Reads 0
Downloads 0

Thermal energy storage is recognized as a key technology in the energy transition the world is facing today. But the main technical barrier this technology has to achieve wider deployment the low thermal conductivity of the materials used, the so-called phase change materials (PCM). This paper presents a new concept for thermal conductivity enhancement of a PCM tank using metal wool. Metal wool is one of the least studied method to enhance PCM thermal conductivity, while it has high potential to do so at a low cost. This study shows the experimental prototype that developed for the validation of the effective conductivity of the composite formed by NaNO3 salts and metal wool. The metal wool used is produced and arranged to ensure the right porosity and packaging to increase 300% the effective thermal conductivity of the mixture. The model validated confirms the movement of the fluid during the melting standardizes the temperature of the molten material, increasing the transference. The model also validates the new composite, with wool and NaNO3 as PCM, as one of the most promising materials to be used in applications that need heat to be stored at around 280–300 °C. Such applications include use of solar energy and waste heat in industry.

ACS Style

Cristina Prieto; Carlos Rubio; Luisa F. Cabeza. New phase change material storage concept including metal wool as heat transfer enhancement method for solar heat use in industry. Journal of Energy Storage 2020, 33, 101926 .

AMA Style

Cristina Prieto, Carlos Rubio, Luisa F. Cabeza. New phase change material storage concept including metal wool as heat transfer enhancement method for solar heat use in industry. Journal of Energy Storage. 2020; 33 ():101926.

Chicago/Turabian Style

Cristina Prieto; Carlos Rubio; Luisa F. Cabeza. 2020. "New phase change material storage concept including metal wool as heat transfer enhancement method for solar heat use in industry." Journal of Energy Storage 33, no. : 101926.

Journal article
Published: 16 July 2020 in International Journal of Hydrogen Energy
Reads 0
Downloads 0

Solar thermochemical water splitting was successfully demonstrated with monolithic receiver-reactors in field at 50 kW scale. Since monolithic receiver-reactors are limited in size, several of the reactors will have to be combined in receiver-reactor arrays for large-scale plants. In this study, the yearly performance of solar thermochemical plants for hydrogen production implementing receiver-reactor arrays is investigated. Thereto, a transient receiver-reactor model is used in combination with realistic hourly flux profiles from dedicated MW high temperature solar concentrator systems. The batched operation of receiver-reactors leads to particular requirements of the array. Therefore, an array efficiency is introduced and different control strategies for the solar field are analyzed for performance optimization. Advanced strategies have the potential to substantially (~46%) improve the overall performance compared to the base case. Further design and operational optimization approaches are discussed, which allow approaching the theoretical array performance limit.

ACS Style

Stefan Brendelberger; Andreas Rosenstiel; Anton Lopez-Roman; Cristina Prieto; Christian Sattler. Performance analysis of operational strategies for monolithic receiver-reactor arrays in solar thermochemical hydrogen production plants. International Journal of Hydrogen Energy 2020, 45, 26104 -26116.

AMA Style

Stefan Brendelberger, Andreas Rosenstiel, Anton Lopez-Roman, Cristina Prieto, Christian Sattler. Performance analysis of operational strategies for monolithic receiver-reactor arrays in solar thermochemical hydrogen production plants. International Journal of Hydrogen Energy. 2020; 45 (49):26104-26116.

Chicago/Turabian Style

Stefan Brendelberger; Andreas Rosenstiel; Anton Lopez-Roman; Cristina Prieto; Christian Sattler. 2020. "Performance analysis of operational strategies for monolithic receiver-reactor arrays in solar thermochemical hydrogen production plants." International Journal of Hydrogen Energy 45, no. 49: 26104-26116.

Journal article
Published: 08 June 2020 in Energies
Reads 0
Downloads 0

Industries with fast-developing technologies and knowledge-intensive business services rely on the development of scientific knowledge for their growth. This is also true in the renewable energy industry such as in concentrating solar power (CSP) plants, which have undergone intense development and expansion in the last two decades. Yet knowledge generation is not sufficient; its dissemination and internalization by the industry is indispensable for new product development. This paper contributes to providing empirical evidence on the known link between knowledge development and firm growth. In 10 years the cost of electricity produced through CSP has decreased five-fold. This decrease has only been possible due to innovation projects developed through a complex network of research and development (R&D) collaborations and intense investment, both public and (to a greater extent) private. The development and construction of pilot plants and demonstration facilities are shown to be key in maturing innovations for commercialization. This is an example of how the private sector is contributing to the decarbonisation of our energy system, contributing to the objectives of climate change mitigation.

ACS Style

Cristina Prieto; Sonia Fereres; Luisa F. Cabeza. The Role of Innovation in Industry Product Deployment: Developing Thermal Energy Storage for Concentrated Solar Power. Energies 2020, 13, 1 .

AMA Style

Cristina Prieto, Sonia Fereres, Luisa F. Cabeza. The Role of Innovation in Industry Product Deployment: Developing Thermal Energy Storage for Concentrated Solar Power. Energies. 2020; 13 (11):1.

Chicago/Turabian Style

Cristina Prieto; Sonia Fereres; Luisa F. Cabeza. 2020. "The Role of Innovation in Industry Product Deployment: Developing Thermal Energy Storage for Concentrated Solar Power." Energies 13, no. 11: 1.

Journal article
Published: 21 February 2020 in Solar Energy
Reads 0
Downloads 0

Pyromark is a silicone-based black paint that is commonly used in concentrated solar power plants because of its relatively high absorptivity. However, it has very low durability, which decreases the optical performance of the surfaces coated with this paint over time, thus reducing the thermal efficiencies of these plants. Recent studies have tried to develop promising materials to circumvent this problem; however, there is no commercial substitute for Pyromark as yet. Therefore, improving the durability of this paint is necessary to enhance the power plants operation. In this work, we study the durability of Pyromark through the micro-wear performance of the coatings assessed by scratch tests. Curing and vitrification procedures control the physical and mechanical properties of the manufactured coatings. For the first time, we demonstrate that the time-dependent behavior and related properties such as the material relaxation times are key parameters controlling the durability of this type of paint. The ability of the material to store elastic energy also explains why some consolidation procedures are better to increase its durability.

ACS Style

N. Martínez; A. Rico; C.J. Múnez; Cristina Prieto; Pedro Poza. Improving durability of silicone-based paint coatings used in solar power plants by controlling consolidation procedures. Solar Energy 2020, 199, 585 -595.

AMA Style

N. Martínez, A. Rico, C.J. Múnez, Cristina Prieto, Pedro Poza. Improving durability of silicone-based paint coatings used in solar power plants by controlling consolidation procedures. Solar Energy. 2020; 199 ():585-595.

Chicago/Turabian Style

N. Martínez; A. Rico; C.J. Múnez; Cristina Prieto; Pedro Poza. 2020. "Improving durability of silicone-based paint coatings used in solar power plants by controlling consolidation procedures." Solar Energy 199, no. : 585-595.

Journal article
Published: 20 November 2019 in Renewable Energy
Reads 0
Downloads 0

Concentrated solar power (CSP) is not currently cost competitive with conventional power generation or other solar energy technologies, but it is attractive because it integrates commercially viable large-scale thermal energy storage (TES). To improve performance and reduce costs, supercritical carbon dioxide (s-CO2) power cycles have been proposed to increase the thermal-to-electric conversion to values above 50%. However, to achieve this target, the solar energy collected by the receiver and stored in the TES must be delivered to the power turbine at a temperature at or above 700 °C, while current advanced plants only provide thermal energy at 565 °C. For the first time, a high temperature (700 °C) molten salt experimental pilot plant for CSP was designed, built, and tested by Abengoa using carbonate salts as the heat transfer fluid. We demonstrate the feasibility of large-scale, industrially relevant operation between 400 and 700 °C, thus providing a solution to integrate higher efficiency s-CO2 power cycles. We address the key points in material compatibility, component design, instrumentation and system integration. Operational aspects such as preheating and filling procedures, start-up, maximum temperature reached, and the main challenges faced are described in detail. The heat losses in the loop and components are analyzed. We show that with appropriate electrical heat tracing elements, operation with carbonates is feasible and that the main subsystems that must be redesigned are the high temperature tanks and pumps. Lessons learned from the plant operation are summarized here to guide the design of future commercial scale high temperature molten salt plants.

ACS Style

Cristina Prieto; Sonia Fereres; Francisco Javier Ruiz-Cabañas; Alfonso Rodriguez-Sanchez; Cristina Montero. Carbonate molten salt solar thermal pilot facility: Plant design, commissioning and operation up to 700 °C. Renewable Energy 2019, 151, 528 -541.

AMA Style

Cristina Prieto, Sonia Fereres, Francisco Javier Ruiz-Cabañas, Alfonso Rodriguez-Sanchez, Cristina Montero. Carbonate molten salt solar thermal pilot facility: Plant design, commissioning and operation up to 700 °C. Renewable Energy. 2019; 151 ():528-541.

Chicago/Turabian Style

Cristina Prieto; Sonia Fereres; Francisco Javier Ruiz-Cabañas; Alfonso Rodriguez-Sanchez; Cristina Montero. 2019. "Carbonate molten salt solar thermal pilot facility: Plant design, commissioning and operation up to 700 °C." Renewable Energy 151, no. : 528-541.

Journal article
Published: 01 November 2019 in Applied Energy
Reads 0
Downloads 0
ACS Style

Cristina Prieto; Luisa F. Cabeza. Thermal energy storage (TES) with phase change materials (PCM) in solar power plants (CSP). Concept and plant performance. Applied Energy 2019, 254, 1 .

AMA Style

Cristina Prieto, Luisa F. Cabeza. Thermal energy storage (TES) with phase change materials (PCM) in solar power plants (CSP). Concept and plant performance. Applied Energy. 2019; 254 ():1.

Chicago/Turabian Style

Cristina Prieto; Luisa F. Cabeza. 2019. "Thermal energy storage (TES) with phase change materials (PCM) in solar power plants (CSP). Concept and plant performance." Applied Energy 254, no. : 1.

Journal article
Published: 26 September 2019 in Journal of Energy Storage
Reads 0
Downloads 0

Postmortem tests were performed over components removed from the TES-PS10 pilot plant after almost four years of continuous operation being exposed to solar salts under representative commercial operation conditions. Accordingly, corrosion performance of plates sections extracted from both storage tanks and samples cut from the hot molten salts pump were evaluated. Corrosion damage extension, oxides layers morphology, and corrosion products chemistry were analyzed by X-ray diffraction, energy dispersive X-ray spectrometry, optical microscopy, and SEM. In addition to materials compatibility with molten salts, mechanical tests were carried out over the storage tanks plates sections. Although the corrosion damage extension over the plates extracted from storage tanks was low and the mechanical properties were according to the standard, some interesting observations were seen. For example, a sample extracted from the hot storage tank and exposed to intermittent contact with molten salts showed some areas characterized by the growth of a non-protective oxide scale. Moreover, localized corrosion with slight penetration through the base material was identified for all storage plates samples under evaluation. On the other hand, the molten salt pump parts under study showed adherent and uniform oxides layers without detecting corrosion–erosion phenomena. Some cavities were found in the discharge elbow, and these imperfections were associated to a bad metallurgical quality during casting. Summarizing, corrosion phenomena suffered by the components under evaluation could be corrected in future plants by applying the lessons learned discussed in this study. As conclusion, materials selection analyzed within this postmortem evaluation is valid from the corrosion point of view to be used in the design of commercial TES systems in PTC plants.

ACS Style

F. Javier Ruiz-Cabañas; Cristina Prieto; Virginia Madina; A. Inés Fernández; Luisa F. Cabeza. TES-PS10 postmortem tests: Carbon steel corrosion performance exposed to molten salts under relevant operation conditions and lessons learnt for commercial scale-up. Journal of Energy Storage 2019, 26, 100922 .

AMA Style

F. Javier Ruiz-Cabañas, Cristina Prieto, Virginia Madina, A. Inés Fernández, Luisa F. Cabeza. TES-PS10 postmortem tests: Carbon steel corrosion performance exposed to molten salts under relevant operation conditions and lessons learnt for commercial scale-up. Journal of Energy Storage. 2019; 26 ():100922.

Chicago/Turabian Style

F. Javier Ruiz-Cabañas; Cristina Prieto; Virginia Madina; A. Inés Fernández; Luisa F. Cabeza. 2019. "TES-PS10 postmortem tests: Carbon steel corrosion performance exposed to molten salts under relevant operation conditions and lessons learnt for commercial scale-up." Journal of Energy Storage 26, no. : 100922.

Conference paper
Published: 01 September 2019 in 2019 European Space Power Conference (ESPC)
Reads 0
Downloads 0

In-Situ Resource Utilization (ISRU) technologies for future deep-space exploration is a current hot topic considering planned lunar missions for the coming years. Energy generation and storage using regolith can be useful not only for future lunar human outposts but also to assist lunar mining or construction activities during the lunar night. Here we explore the design of a packed bed Thermal Energy Storage (TES) system using regolith as the storage media through a numerical model. System requirements are analyzed depending on landing sites and mission needs. Different heat transfer fluids (HTF) are evaluated for the TES charge/discharge, using media available from other complementary ISRU processes (i.e. oxygen/water production from lunar regolith) or gases indispensable for life support systems. Raw regolith of varied composition, several Earth materials and processed/reduced regolith are compared, and different TES integration options are discussed.

ACS Style

Sonia Fereres; Sergio Escario; Cristina Prieto; Sonia De La Rosa. Regolith Packed Bed Thermal Energy Storage for Lunar Night Survival. 2019 European Space Power Conference (ESPC) 2019, 1 -7.

AMA Style

Sonia Fereres, Sergio Escario, Cristina Prieto, Sonia De La Rosa. Regolith Packed Bed Thermal Energy Storage for Lunar Night Survival. 2019 European Space Power Conference (ESPC). 2019; ():1-7.

Chicago/Turabian Style

Sonia Fereres; Sergio Escario; Cristina Prieto; Sonia De La Rosa. 2019. "Regolith Packed Bed Thermal Energy Storage for Lunar Night Survival." 2019 European Space Power Conference (ESPC) , no. : 1-7.

Journal article
Published: 18 June 2019 in Energies
Reads 0
Downloads 0

Parabolic trough collector (PTC) technology is currently the most mature solar technology, which has led to the accumulation of relevant operational experience. The overall performance and efficiency of these plants depends on several components, and the heat transfer fluid (HTF) is one of the most important ones. Using molten salts as HTFs has the advantage of being able to work at higher temperatures, but it also has the disadvantage of the potential freezing of the HTF in pipes and components. This paper models and evaluates two methods of freeze recovery, which is needed for this HTF system design: Heat tracing in pipes and components, and impedance melting in the solar field. The model is used to compare the parasitic consumption in three molten salts mixtures, namely Solar Salt, HiTec, and HiTec XL, and the feasibility of this system in a freezing event. After the investigation of each of these subsystems, it was concluded that freeze recovery for a molten salt plant is possible.

ACS Style

Cristina Prieto; Alfonso Rodríguez-Sánchez; F. Javier Ruiz-Cabañas; Luisa F. Cabeza. Feasibility Study of Freeze Recovery Options in Parabolic Trough Collector Plants Working with Molten Salt as Heat Transfer Fluid. Energies 2019, 12, 2340 .

AMA Style

Cristina Prieto, Alfonso Rodríguez-Sánchez, F. Javier Ruiz-Cabañas, Luisa F. Cabeza. Feasibility Study of Freeze Recovery Options in Parabolic Trough Collector Plants Working with Molten Salt as Heat Transfer Fluid. Energies. 2019; 12 (12):2340.

Chicago/Turabian Style

Cristina Prieto; Alfonso Rodríguez-Sánchez; F. Javier Ruiz-Cabañas; Luisa F. Cabeza. 2019. "Feasibility Study of Freeze Recovery Options in Parabolic Trough Collector Plants Working with Molten Salt as Heat Transfer Fluid." Energies 12, no. 12: 2340.

Review
Published: 15 May 2019 in Energy Storage
Reads 0
Downloads 0

Current CSP plants that operate at the highest temperature use molten salts as both Heat Transfer Fluid (HTF) and Thermal Energy Storage (TES) medium. Molten salts can reach up to 565 °C before becoming chemically unstable and highly corrosive. This is one of the higher weakness of the technology. Solid particles have been proposed to overcome current working temperature limits, since the particle media can be stable for temperatures close to 1000 °C. This work presents a review of solid particles candidates to be used as HTF and TES in CSP plants in open receivers. In addition, the interactions between solid particles with major system components are described in this review e.g. with TES system or heat exchanger. The parameters and properties of solid particles are identified from the material science point of view explaining their nature and the relation to the power plant efficiency and lifetime durability. Finally, future development is proposed; such as material selection according to each specific design, materials characterization or durability test. This article is protected by copyright. All rights reserved.

ACS Style

Alejandro Calderón; Camila Barreneche; Anabel Palacios; Mercè Segarra; Cristina Prieto; Alfonso Rodriguez‐Sanchez; Ana Ines Fernandez. Review of solid particle materials for heat transfer fluid and thermal energy storage in solar thermal power plants. Energy Storage 2019, 1, 1 .

AMA Style

Alejandro Calderón, Camila Barreneche, Anabel Palacios, Mercè Segarra, Cristina Prieto, Alfonso Rodriguez‐Sanchez, Ana Ines Fernandez. Review of solid particle materials for heat transfer fluid and thermal energy storage in solar thermal power plants. Energy Storage. 2019; 1 (4):1.

Chicago/Turabian Style

Alejandro Calderón; Camila Barreneche; Anabel Palacios; Mercè Segarra; Cristina Prieto; Alfonso Rodriguez‐Sanchez; Ana Ines Fernandez. 2019. "Review of solid particle materials for heat transfer fluid and thermal energy storage in solar thermal power plants." Energy Storage 1, no. 4: 1.

Journal article
Published: 22 February 2019 in Solar Energy
Reads 0
Downloads 0

Thermal energy storage (TES) systems are key components of concentrating solar power plants in order to offer energy dispatchability to adapt the electricity power production to the curve demand. Nitrate molten salts are the storage media used today in concentrated solar power plants. They are also used as heat transfer fluid (HTF) in the molten salt tower (MST) technology. Traditional MST plants work in the temperature range of 240–565 °C using the so-called solar salt, a mixture of 60–40 wt% of NaNO3 and KNO3. This study wants to optimize the thermal energy storage cost of the solar concentration technology by analysing different mixtures of solar salts, using different percentages of NaNO3 and KNO3 in the mixture. The new mixtures seek a reduction in the cost of the storage material while optimizing its physical and chemical properties. The study shows how an increase in the proportion of sodium nitrate for a new binary solar salt to 78–22 wt%, produces an increase in the heat capacity of the mixture by reducing the necessary inventory of salts in the system. However, the new salt presents an increase in the melting point, going from 240 °C to 279 °C, which makes the operation of the system difficult. The impact on the cost of this optimization in the performance of a commercial plant was analysed. The plant chosen to evaluate the impact is a tower technology plant with 85 MWe power and 13 h of storage. The study shows a LCOE reduction of up to 0.6% for the new mixture with higher sodium nitrate.

ACS Style

Melanie Durth; Cristina Prieto; Alfonso Rodríguez-Sánchez; David Patiño-Rodríguez; Luisa F. Cabeza. Effects of sodium nitrate concentration on thermophysical properties of solar salts and on the thermal energy storage cost. Solar Energy 2019, 182, 57 -63.

AMA Style

Melanie Durth, Cristina Prieto, Alfonso Rodríguez-Sánchez, David Patiño-Rodríguez, Luisa F. Cabeza. Effects of sodium nitrate concentration on thermophysical properties of solar salts and on the thermal energy storage cost. Solar Energy. 2019; 182 ():57-63.

Chicago/Turabian Style

Melanie Durth; Cristina Prieto; Alfonso Rodríguez-Sánchez; David Patiño-Rodríguez; Luisa F. Cabeza. 2019. "Effects of sodium nitrate concentration on thermophysical properties of solar salts and on the thermal energy storage cost." Solar Energy 182, no. : 57-63.

Review
Published: 06 September 2018 in Energies
Reads 0
Downloads 0

The aim of this study is to perform a review of the state-of-the-art of the reactors available in the literature, which are used for solid–gas reactions or thermal decomposition processes around 1000 °C that could be further implemented for thermochemical energy storage in CSP (concentrated solar power) plants, specifically for SPT (solar power tower) technology. Both direct and indirect systems can be implemented, with direct and closed systems being the most studied ones. Among direct and closed systems, the most used configuration is the stacked bed reactor, with the fixed bed reactor being the most frequent option. Out of all of the reactors studied, almost 70% are used for solid–gas chemical reactions. Few data are available regarding solar efficiency in most of the processes, and the available information indicates relatively low values. Chemical reaction efficiencies show better values, especially in the case of a fluidized bed reactor for solid–gas chemical reactions, and fixed bed and rotary reactors for thermal decompositions.

ACS Style

Gabriel Zsembinszki; Aran Solé; Camila Barreneche; Cristina Prieto; A. Inés Fernández; Luisa F. Cabeza. Review of Reactors with Potential Use in Thermochemical Energy Storage in Concentrated Solar Power Plants. Energies 2018, 11, 2358 .

AMA Style

Gabriel Zsembinszki, Aran Solé, Camila Barreneche, Cristina Prieto, A. Inés Fernández, Luisa F. Cabeza. Review of Reactors with Potential Use in Thermochemical Energy Storage in Concentrated Solar Power Plants. Energies. 2018; 11 (9):2358.

Chicago/Turabian Style

Gabriel Zsembinszki; Aran Solé; Camila Barreneche; Cristina Prieto; A. Inés Fernández; Luisa F. Cabeza. 2018. "Review of Reactors with Potential Use in Thermochemical Energy Storage in Concentrated Solar Power Plants." Energies 11, no. 9: 2358.

Journal article
Published: 05 September 2018 in Solar Energy Materials and Solar Cells
Reads 0
Downloads 0

The eutectic mixture Li2CO3-Na2CO3-K2CO3 is investigated as a high temperature heat transfer fluid and storage medium alternative for molten salt solar thermal power plants. This salt has an operating temperature range of 400–700 °C, enabling the use of higher temperature/efficiency power cycles. However, this carbonate mixture is known to thermally decompose in air. This study evaluates the thermal stability of the salt mixture under different cover gases: air, nitrogen, carbon dioxide, and an 80/20 carbon dioxide/air mixture. Initial characterization is performed through thermogravimetric analysis (TGA), followed by larger scale testing in a custom-made reactor to simulate conditions closer to its practical use. The results show improved thermal stability with a CO2 atmosphere. The decomposition kinetics under different cover gases are estimated from TGA data. However, larger-scale, longer duration experiments show much slower decomposition rates compared to the classical TGA approach. These findings indicate that the main contribution to mass loss in TGA is due to vaporization rather than thermal decomposition. Thus, a proper evaluation of the molten salt´s thermal stability can only be obtained from reactor experiments where vaporization is inhibited. Very long induction periods (of the order of days) are observed, suggesting that the kinetic decomposition mechanism is a nucleation and growth type. Other considerations for future plants incorporating these high temperature salts are discussed.

ACS Style

Sonia Fereres; Cristina Prieto; Pablo Giménez Gavarrell; Alfonso Rodríguez; Pedro Enrique Sánchez-Jiménez; Luis A Perez-Maqueda. Molten carbonate salts for advanced solar thermal energy power plants: Cover gas effect on fluid thermal stability. Solar Energy Materials and Solar Cells 2018, 188, 119 -126.

AMA Style

Sonia Fereres, Cristina Prieto, Pablo Giménez Gavarrell, Alfonso Rodríguez, Pedro Enrique Sánchez-Jiménez, Luis A Perez-Maqueda. Molten carbonate salts for advanced solar thermal energy power plants: Cover gas effect on fluid thermal stability. Solar Energy Materials and Solar Cells. 2018; 188 ():119-126.

Chicago/Turabian Style

Sonia Fereres; Cristina Prieto; Pablo Giménez Gavarrell; Alfonso Rodríguez; Pedro Enrique Sánchez-Jiménez; Luis A Perez-Maqueda. 2018. "Molten carbonate salts for advanced solar thermal energy power plants: Cover gas effect on fluid thermal stability." Solar Energy Materials and Solar Cells 188, no. : 119-126.

Journal article
Published: 27 August 2018 in Solar Energy
Reads 0
Downloads 0

Nowadays, the most matured thermal energy storage (TES) technology for Concentrated Solar Power (CSP) plants is the use of molten solar salts (60 wt% NaNO3 – 40 wt% KNO3), but the thermal decomposition of nitrate salts can result in changes in the composition of molten salts or potential risks of NOx emissions. Up to now, all studies on the decomposition of nitrates in TES systems focus on the effect of the effect of sodium and potassium nitrates in contact with the container material and the NOx emissions formation, but none investigate the effect or contribution of impurities in it. Moreover, although the chemistry of the nitrates decomposition is well known, there is a big uncertainty in commercial solar plants on the production rate of NOx. The only cation in nitrates from mining origin is magnesium, and since it occurs as nitrate, it does contribute to NOx formation. This paper studies the effect of such impurity in the thermal decomposition of the solar salt. The results show that the impurity Mg(NO3)2 is the main source of NOx emissions in solar salts during the commissioning of the plant due to its thermal decomposition during the melting process. But as described this NOx production can be handled by vents and abatement systems if it is needed.

ACS Style

Cristina Prieto; F. Javier Ruiz-Cabañas; Alfonso Rodríguez-Sanchez; Carlos Rubio Abujas; Ana Ines Fernandez; Mónica Martínez; Eduard Oró; Luisa F. Cabeza. Effect of the impurity magnesium nitrate in the thermal decomposition of the solar salt. Solar Energy 2018, 192, 186 -192.

AMA Style

Cristina Prieto, F. Javier Ruiz-Cabañas, Alfonso Rodríguez-Sanchez, Carlos Rubio Abujas, Ana Ines Fernandez, Mónica Martínez, Eduard Oró, Luisa F. Cabeza. Effect of the impurity magnesium nitrate in the thermal decomposition of the solar salt. Solar Energy. 2018; 192 ():186-192.

Chicago/Turabian Style

Cristina Prieto; F. Javier Ruiz-Cabañas; Alfonso Rodríguez-Sanchez; Carlos Rubio Abujas; Ana Ines Fernandez; Mónica Martínez; Eduard Oró; Luisa F. Cabeza. 2018. "Effect of the impurity magnesium nitrate in the thermal decomposition of the solar salt." Solar Energy 192, no. : 186-192.

Journal article
Published: 01 June 2018 in Renewable Energy
Reads 0
Downloads 0

Renewable energies are main players to ensure the long-term energy supply. Solar power plants with thermal energy storage (TES) are one of the available renewable technologies which have more potential. Nowadays, there are still several aspects in the design and operation of these power plants which need to be improved, such as the correct operation of some specific instrumentation, the compatibility between TES materials and storage tanks materials, and operational process strategies. This paper presents the acquired experience during the design, start-up, and operation of a kWh scale pilot experimental facility built at the University of Lleida (Spain) together with Abengoa Research (Spain) in 2008. The versatility of this facility has allowed simulating real working conditions and therefore testing different TES systems, TES materials, solar power plant components, and operational strategies focused on TES for temperatures up to 400 ºC. In the present paper, the authors show the lessons learnt at pilot and present the main problems and limitations encountered, and give advices of this experimental set-up to extrapolate the data to real plant, to provide solutions to technical problems and reduce the cost of commercial plants.

ACS Style

Gerard Peiró; Cristina Prieto; Jaume Gasia; Aleix Jové; Laia Miró; Luisa F. Cabeza. Two-tank molten salts thermal energy storage system for solar power plants at pilot plant scale: Lessons learnt and recommendations for its design, start-up and operation. Renewable Energy 2018, 121, 236 -248.

AMA Style

Gerard Peiró, Cristina Prieto, Jaume Gasia, Aleix Jové, Laia Miró, Luisa F. Cabeza. Two-tank molten salts thermal energy storage system for solar power plants at pilot plant scale: Lessons learnt and recommendations for its design, start-up and operation. Renewable Energy. 2018; 121 ():236-248.

Chicago/Turabian Style

Gerard Peiró; Cristina Prieto; Jaume Gasia; Aleix Jové; Laia Miró; Luisa F. Cabeza. 2018. "Two-tank molten salts thermal energy storage system for solar power plants at pilot plant scale: Lessons learnt and recommendations for its design, start-up and operation." Renewable Energy 121, no. : 236-248.