scholarly journals Improved High Temperature Solar Absorbers for Use in Concentrating Solar Power Central Receiver Applications

2011 ◽  
Author(s):  
Andrea Ambrosini ◽  
Timothy N. Lambert ◽  
Marlene Bencomo ◽  
Aaron Hall ◽  
Kent vanEvery ◽  
...  
Keyword(s):  
High Temperature ◽  
Solar Power ◽  
Low Cost ◽  
Concentrating Solar Power ◽  
Solar Absorptance ◽  
Thermal Emittance ◽  
Solar Absorbers ◽  
Operating Temperatures ◽  
Stability Issues ◽  
The Cost

Concentrating solar power (CSP) systems use solar absorbers to convert the heat from sunlight to electric power. Increased operating temperatures are necessary to lower the cost of solar-generated electricity by improving efficiencies and reducing thermal energy storage costs. Durable new materials are needed to cope with operating temperatures < 600°C. The current coating technology (Pyromark High Temperature paint) has a solar absorptance in excess of 0.95 but a thermal emittance greater than 0.8, which results in large thermal losses at high temperatures. In addition, because solar receivers operate in air, these coatings have long term stability issues that add to the operating costs of CSP facilities. Ideal absorbers must have high solar absorptance (>0.95) and low thermal emittance (<0.3 at receiver surface operating temperatures), be stable in air, and be low-cost and readily manufacturable. Recent efforts at Sandia National Laboratories have begun to address the issue of more efficient solar selective coatings for tower applications. This paper will present an overview of these efforts which address the development of new coatings on several fronts.

scholarly journals Improved high temperature solar absorbers for use in Concentrating Solar Power central receiver applications.

2010 ◽  
Author(s):  
Ellen Beth Stechel ◽  
Andrea Ambrosini ◽  
Aaron Christopher Hall ◽  
Timothy L. Lambert ◽  
Chad Lynn Staiger ◽  
...  
Keyword(s):  
High Temperature ◽  
Solar Power ◽  
Concentrating Solar Power ◽  
Solar Absorbers ◽  
Central Receiver ◽  
Power Central

scholarly journals Analysis of a Fluidized-Bed Particle/Supercritical-CO2 Heat Exchanger in a Concentrating Solar Power System

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Zhiwen Ma ◽  
Janna Martinek
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Heat Exchanger ◽  
Fluidized Bed ◽  
High Efficiency ◽  
Solar Power ◽  
Concentrating Solar Power ◽  
Power Cycle ◽  
Temperature Heat ◽  
The Cost

Abstract Concentrating solar power (CSP) development has focused on increasing the energy conversion efficiency and lowering the capital cost. To improve performance, CSP research is moving to high-temperature and high-efficiency designs. One technology approach is to use inexpensive, high-temperature heat transfer fluids and storage, integrated with a high-efficiency power cycle such as the supercritical carbon dioxide (sCO2) Brayton power cycle. The sCO2 Brayton power cycle has strong potential to achieve performance targets of 50% thermal-to-electric efficiency and dry cooling at an ambient temperature of up to 40 °C and to reduce the cost of power generation. Solid particles have been proposed as a possible high-temperature heat transfer or storage medium that is inexpensive and stable at high temperatures above 1000 °C. The particle/sCO2 heat exchanger (HX) provides a connection between the particles and sCO2 fluid in emerging sCO2 power cycles. This article presents heat transfer modeling to analyze the particle/sCO2 HX design and assess design tradeoffs including the HX cost. The heat transfer process was modeled based on a particle/sCO2 counterflow configuration, and empirical heat transfer correlations for the fluidized bed and sCO2 were used to calculate heat transfer area and estimate the HX cost. A computational fluid dynamics simulation was applied to characterize particle distribution and fluidization. This article shows a path to achieve the cost and performance objectives for a particle/sCO2 HX design by using fluidized-bed technology.

Development Steps for Concentrating Solar Power Technologies With Maximum Impact on Cost Reduction: Results of the European ECOSTAR Study

Solar Energy ◽  
2005 ◽  
Author(s):  
Robert Pitz-Paal ◽  
Ju¨rgen Dersch ◽  
Barbara Milow ◽  
Fe´lix Te´llez ◽  
Alain Ferriere ◽  
...  
Keyword(s):  
Cost Reduction ◽  
Power Plants ◽  
Solar Power ◽  
Low Cost ◽  
Performance Model ◽  
Concentrating Solar Power ◽  
Cost Information ◽  
Power Cycles ◽  
Electricity Cost ◽  
The Cost

Beside continuous implementation of concentrating solar power plants (CSP) in Europe, which stipulate cost reduction by mass production effects, further R&D activities are necessary to achieve the cost competitiveness to fossil power generation. Therefore the cost range of 15–20 cents€/kWh for the currently planned CSP systems in Europe has to be decreased by a factor of 2–4. The European Concentrated Solar Thermal Roadmap (ECOSTAR) study that is conducted by leading CSP research institutes in Europe intends to stipulate the direction for R&D activities in the context of cost reduction. It uses a common methodology approach, based on an annual performance model to identify the most essential technical innovations that will reduce the cost of seven different CSP system concepts, which are currently under promotion world wide. The potential of innovative concepts for solar light weight concentrators, low-cost thermal energy storage concepts, solar receivers/absorbers and power cycles are in the main focus of interest. The results of the study include a description of the value of CSP power, the sensitivity of the electricity cost information, a list of innovations that have been investigated and recommendations for the focus of further R&D work.

Thermal Modeling of a Multi-Cavity Array Receiver Performance for Concentrating Solar Power Generation

2015 ◽  
Author(s):  
Austin Fleming ◽  
Zhiwen Ma ◽  
Tim Wendelin ◽  
Heng Ban ◽  
Charlie Folsom
Keyword(s):  
Power Generation ◽  
Renewable Energy ◽  
High Temperature ◽  
Solar Power ◽  
Freezing Point ◽  
Low Cost ◽  
Thermal Modeling ◽  
Solid Particles ◽  
Concentrating Solar Power ◽  
Receiver Performance

Concentrating solar power (CSP) plants can provide dispatchable power with the thermal energy storage (TES) capability for greater renewable-energy grid penetration. To increase the market competitiveness, CSP technology needs to increase the solar-to-electric efficiency and reduce costs in the areas of solar collection from the heliostat field to the receiver, energy conversion systems, and TES. The current state-of-the-art molten-salt systems have limitations regarding both the potential for cost reduction and improvements in performance. Even with significant improvements in operating performance, these systems face major challenges to satisfy the performance targets, which include high-temperature stability (>650°C), low freezing point (<0°C), and material compatibility with high-temperature metals (>650°C) at a reduced cost. The fluidized-bed CSP (FB-CSP) plant being developed by the National Renewable Energy Laboratory (NREL) has the potential to overcome the above issues with substantially lower cost. The particle receiver is a critical component to enable the FB-CSP system. This paper introduces the development of an innovative receiver design using the blackbody design mechanism by collecting solar heat with absorber tubes that transfer the radiant heat to flowing particles. The particle and receiver materials can withstand temperatures of >1000°C because the receiver can use low-cost materials, such as ceramics and stainless steel, and the solid particles can be any low-cost, stable materials such as sand or ash for particle containment and TES. The heated particles can be stored in containers for TES or supply heat for power generation. This study investigated the performance of convection, reflection, and infrared (IR) re-radiation losses on the absorber solar receiving side. We developed a flux model to predict the reflection losses from the absorber tubes based on the NREL SolTrace program, and conducted thermal modeling by using the Fluent Software. This paper presents the thermal modeling and results on the receiver performance. The receiver configuration may have broad applications for different heattransfer fluids (HTFs), including gas, liquid, or the solid particle-based system in our receiver development.

scholarly journals A Review of Conventional and Innovative- Sustainable Methods for Cleaning Reflectors in Concentrating Solar Power Plants

2018 ◽  
Vol 10 (11) ◽  
pp. 3937 ◽  
Author(s):  
Sahar Bouaddi ◽  
Aránzazu Fernández-García ◽  
Chris Sansom ◽  
Jon Sarasua ◽  
Fabian Wolfertstetter ◽  
...  
Keyword(s):  
Power Plants ◽  
Solar Power ◽  
Alternative Methods ◽  
Concentrating Solar Power ◽  
Water Based ◽  
Solar Power Plants ◽  
Cleaning Methods ◽  
The Cost ◽  
Solar Field ◽  
High Reflectance

The severe soiling of reflectors deployed in arid and semi arid locations decreases their reflectance and drives down the yield of the concentrating solar power (CSP) plants. To alleviate this issue, various sets of methods are available. The operation and maintenance (O&M) staff should opt for sustainable cleaning methods that are safe and environmentally friendly. To restore high reflectance, the cleaning vehicles of CSP plants must adapt to the constraints of each technology and to the layout of reflectors in the solar field. Water based methods are currently the most commonly used in CSP plants but they are not sustainable due to water scarcity and high soiling rates. The recovery and reuse of washing water can compensate for these methods and make them a more reasonable option for mediterranean and desert environments. Dry methods, on the other hand, are gaining more attraction as they are more suitable for desert regions. Some of these methods rely on ultrasonic wave or vibration for detaching the dust bonding from the reflectors surface, while other methods, known as preventive methods, focus on reducing the soiling by modifying the reflectors surface and incorporating self cleaning features using special coatings. Since the CSP plants operators aim to achieve the highest profit by minimizing the cost of cleaning while maintaining a high reflectance, optimizing the cleaning parameters and strategies is of great interest. This work presents the conventional water-based methods that are currently used in CSP plants in addition to sustainable alternative methods for dust removal and soiling prevention. Also, the cleaning effectiveness, the environmental impacts and the economic aspects of each technology are discussed.

Development of High Temperature, Corrosion Resistant Sensors for Concentrating Solar Power Systems

2014 ◽  
Author(s):  
Michael W. Usrey ◽  
Yiping Liu ◽  
Mark Anderson ◽  
Jon Lubbers ◽  
Brady Knowles ◽  
...  
Keyword(s):  
High Temperature ◽  
Molten Salt ◽  
Solar Power ◽  
Thermal Flux ◽  
Temperature Cycling ◽  
Chloride Salt ◽  
Concentrating Solar Power ◽  
Salt Corrosion ◽  
Chloride Salts ◽  
Functional Ceramics

Solar power is a sustainable resource which can reduce the power generated by fossil fuels, lowering greenhouse gas emissions and increasing energy independence. The U.S. Department of Energy’s SunShot Initiative has set goals to increase the efficiency of concentrating solar power (CSP) systems. One SunShot effort to help CSP systems exceed 50% efficiency is to make use of high-temperature heat transfer fluids (HTFs) and thermal energy storage (TES) fluids that can increase the temperature of the power cycle up to 1300°C. Sporian has successfully developed high-temperature operable pressure, temperature, thermal flux, strain, and flow sensors for gas path measurements in high-temperature turbine engines. These sensors are based on a combination of polymer derived ceramic (PDC) sensors, advanced high-temperature packaging, and integrated electronics. The overall objective is the beneficial application of these sensors to CSP systems. Through collaboration with CSP industry stakeholders, Sporian has established a full picture of operational, interface, and usage requirements for trough, tower, and dish CSP architectures. In general, sensors should have accurate measurement, good reliability, reasonable cost, and ease of replacement or repair. Sensors in contact with hot salt HTF and TES fluids will experience temperature cycling on a daily basis, and parts of the system may be drained routinely. Some of the major challenges to high-temperature CSP implementation include molten salt corrosion and flow erosion of the sensors. Potential high-temperature sensor types that have been identified as of interest for CSP HTF/TES applications include temperature, pressure, flow, and level sensors. Candidate solar salts include nitrate, carbonate, and chloride, with different application temperatures ranging from 550°C-900°C. Functional ceramics were soaked for 500 hours in molten nitrate, carbonate, and chloride salts, showing excellent corrosion resistance in chloride salts and good resistance in nitrate salts. The demonstration of functional ceramics in relevant HTFs laid the foundation for full prototype sensor and packaging demonstration. Sporian has developed a packaging approach for ceramic-based sensors in various harsh gaseous environments at temperatures up to 1400°C, but several aspects of that packaging are not compatible with corrosive and electrically conductive HTFs. In addition to consulting published literature, a 300 hour soak test in molten chloride salt allowed the authors to identify suitable structural metals and ceramics. Based on discussions with stakeholders, molten salt corrosion testing and room-temperature water flow testing, suitable for CSP sensor/packaging concepts were identified for future development, and initial prototypes have been built and tested.

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