The influence of atmospheric boundary layer turbulence on the design wind loads and cost of heliostats

Emes, Matthew; Jafari, Azadeh; Coventry, Joe

doi:10.1016/j.solener.2020.07.022

Cited by 25 publications

(17 citation statements)

References 29 publications

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“…• Integral length scales of the turbulent eddies in the atmospheric surface layer relative to the heliostat structure characteristic length correlates strongly with maximum wind loads in stow position and at 90 degrees elevation [123], [138], [139].…”

Section: Wind Loading On Csp Structures (Measurements)mentioning

confidence: 97%

“…Nevertheless, through measurements on instrumented heliostats in field sectors and analysis of their deflection based on spatial relationships to other heliostats (and the tower), analytical models on wake flow interactions and load distributions can be developed and combined with dynamic performance impacts. Figure from [127].…”

Section: Standardsmentioning

confidence: 99%

“…As wind loads increase with heliostat area, the required diameter and thickness of the pedestal, torque tube, and mirror support trusses increase to ensure the combined bending and torsional stresses remain below the ultimate tensile stress of the material within an acceptable limit of safety [129], [130]. Emes et al [127] showed that the increasing mass of steel required to satisfy material stress limits in the structural sections of T-shaped heliostats increases from 18% to 34% of the total direct cost of manufacturing a heliostat with increasing size from 25 m 2 to 150 m 2 .…”

Section: Standardsmentioning

confidence: 99%

“…The maximum wind loads are highly sensitive to the variation of turbulent wind fluctuations with surface roughness and height in the lowest 10 m of the atmospheric boundary layer. A sensitivity analysis by Emes et al [127] estimated that the total heliostat cost increased by approximately $20/m 2 with increasing turbulence from a low-roughness desert terrain to a high-roughness suburban terrain. This has significant implications for designers and manufacturers due to: (1) the significant variability of local wind conditions at different field sites, and (2) the large range of heliostat sizes currently being deployed, from larger heliostats (𝐴𝐴 ≥ 120 m 2 , 𝐻𝐻 ≤ 6 m) developed by Abengoa Solar and Sener, to smaller heliostats (𝐴𝐴 ≤ 20 m 2 , 𝐻𝐻 ≤ 3 m) developed by eSolar, Vast Solar, and BrightSource Energy [131].…”

Section: Standardsmentioning

confidence: 99%

See 3 more Smart Citations

Roadmap to Advance Heliostat Technologies for Concentrating Solar-Thermal Power

Zhu¹,

Augustine²,

Mitchell³

et al. 2022

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Heliostat-based concentrating solar-thermal power (CSP) systems can offer immense potential to provide low-cost, dispatchable renewable thermal and electrical energy to help achieve 100% decarbonized energy infrastructure in the United States. Heliostats are a major determinant of both capital cost and performance of state-of-the-art commercial molten salt towers and Generation 3 CSP systems. 1 In 2021, the U.S. Department of Energy (DOE) Solar Energy Technologies Office (SETO) launched the Heliostat Consortium (HelioCon), a five-year initiative to advance heliostat technologies. The HelioCon mission is threefold: (1) establish strategic core testing and modeling capabilities and infrastructure at national labs; (2) support heliostat technology development in relevant industries; and (3) serve as a central repository to integrate industry, academia, and other stakeholders for heliostat technology research, development, validation, and deployment. In this report, HelioCon presents a roadmapping study on advancing heliostat technologies, intended as a central reference for the entire CSP community.1 More information on Gen3 technologies can be found at https://www.energy.gov/eere/solar/generation-3concentrating-solar-power-systems-gen3-csp. vii This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications. Metrology and StandardsAppropriate measurement techniques and industry standards are fundamental for product design, prototyping, engineering, and improvement. Gaps in metrology:Opto-mechanical metrology (mirror slope error, mirror facet canting error, and heliostat tracking error) is complex, error-prone, and requires high optical precision, necessitating rigorous validation of different technologies using the same measurement parameter(s). Current metrology gaps include:• Lack of at least two viable metrology techniques for a given measurement parameter (such as heliostat tracking error, available for the global CSP industry)• Insufficient or missing validation of any viable metrology technique against a different, trusted metrology technique or ground-truth article. Gaps in standards:Gaps in community-wide standards for site characterization and heliostat design, testing, field design, and field acceptance test protocols result in significant barriers for new developers, extended design cycles, lower investor confidence, and more complicated arbitration between project parties. Gaps include:• Heliostat terminology • Heliostat design guidelines • Heliostat solar field design/simulation guidelines • Heliostat test guidelines • Heliostat solar field acceptance test guidelines • Site characterization guidelines (e.g., wind, topography, soiling characteristics). Recommended pathway forward: Addressing these gaps requires continuing development of new metrology tools and round-robin tests of existing/to-be-developed tools. More importantly, ix This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.o...

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Section: Wind Loading On Csp Structures (Measurements)mentioning

confidence: 97%

Section: Standardsmentioning

confidence: 99%

Section: Standardsmentioning

confidence: 99%

Section: Standardsmentioning

confidence: 99%

See 2 more Smart Citations

Roadmap to Advance Heliostat Technologies for Concentrating Solar-Thermal Power

Zhu¹,

Augustine²,

Mitchell³

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…It is discovered that the unsteady pressure distribution on the mirror surface, as well as the dynamic amplification of the peak wind load, may cause the deformation and displacement of the heliostat structural unit, which has an impact on reducing the tracking error and the leakage loss of solar radiation on the receiver. When Emes et al [23][24][25] investigated how wind speed and ABL turbulence affected the design wind load and cost of heliostats, they found that reducing the design wind speed and altering the terrain roughness might lower the cost of heliostats. The ideal heliostat attitude to prevent hazard was discovered by investigating the wind-induced response of the heliostat at various elevation angles and wind direction angles.…”

Section: Introductionmentioning

confidence: 99%

Transient Evaluation of Wind‐Induced Vibration Response of Heliostat Under Downburst

Xing

et al. 2023

Energy Tech

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As the region with the highest amount of solar radiation, Qinghai–Tibet Plateau has the highest frequency of thunderstorms in China. Downburst generated in thunderstorm can cause high‐intensive wind near the ground, which is a critical threat to heliostats. Herein, the impact of the wind loads on the heliostat response under downburst is investigated using a proven finite‐element model and the influence is also compared with that under atmospheric boundary layer (ABL) wind. The results demonstrate that the downburst development process, the movement of the storm center, and the heliostat's elevation angle are highly associated with the wind‐induced response characteristics of the heliostat under downburst. The maximum displacement and stress of the heliostat with different elevation angles under the downburst are significantly larger than those under ABL wind. Additionally, when the elevation angle of the heliostat is 30°, the maximum value of the mirror's first principal stress under downburst is 1.88 times greater than it is under ABL wind. Therefore, the impact of wind‐induced vibration caused by downburst is necessarily considered on the safety of heliostat in Qinghai‐Tibet Plateau with abundant solar energy resources and high incidence of downbursts.

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