Optimizing dispatch for a concentrated solar power tower

The aim of this study was to conduct thermodynamic and economic analyses of a concentrated solar power (CSP) plant to drive a supercritical CO2 recompression Brayton cycle. The objectives were to assess the system viability in a location of moderate-to-high-temperature solar availability to sCO2 power block during the day and to investigate the role of thermal energy storage with 4, 8, 12, and 16 h of storage to increase the solar share and the yearly energy generating capacity. A case study of system optimization and evaluation is presented in a city in Saudi Arabia (Riyadh). To achieve the highest energy production per unit cost, the heliostat geometry field design integrated with a sCO2 Brayton cycle with a molten-salt thermal energy storage (TES) dispatch system and the corresponding operating parameters are optimized. A solar power tower (SPT) is a type of CSP system that is of particular interest in this research because it can operate at relatively high temperatures. The present SPT-TES field comprises of heliostat field mirrors, a solar tower, a receiver, heat exchangers, and two molten-salt TES tanks. The main thermoeconomic indicators are the capacity factor and the levelized cost of electricity (LCOE). The research findings indicate that SPT-TES with a supercritical CO2 power cycle is economically viable with 12 h thermal storage using molten salt. The results also show that integrating 12 h-TES with an SPT has a high positive impact on the capacity factor of 60% at the optimum LCOE of $0.1078/kW h.

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High Temperature Durability of Solid Particles for Use in Particle Heating Concentrator Solar Power Systems

Volume 1: Combined Energy Cycles, CHP, CCHP, and Smart Grids; Concentrating Solar Power, Solar Thermochemistry and Thermal Energy Storage; Geothermal, Ocean, and Emerging Energy Technologies; Hydrogen Energy Technologies; Low/Zero Emission Power Plants and Carbon Sequestration; Photovoltaics; Wind Energy Systems and Technologies ◽

10.1115/es2014-6586 ◽

2014 ◽

Cited By ~ 5

Author(s):

R. C. Knott ◽

D. L. Sadowski ◽

S. M. Jeter ◽

S. I. Abdel-Khalik ◽

H. A. Al-Ansary ◽

...

Keyword(s):

Heat Transfer ◽

Size Distribution ◽

Solar Power ◽

Solid Particles ◽

Closed Cycle ◽

Concentrated Solar Power ◽

Heat Transfer Medium ◽

Experimental Apparatus ◽

Solar Power Tower ◽

Solid Particulates

Using solid particulates as a heat absorption and transfer medium in solar concentrated systems is a solution for collecting and storing thermal energy. Solid particulates, such as sand, are relatively inexpensive and are much less corrosive and expensive to maintain than molten salts. Small particles may be stored easily, and can be used as a heat transfer medium for use with a suitable heat exchanger. Despite their anticipated low cost, excessive degradation of the particulates requiring replenishment or disrupting operation could impair the overall economics. Consequently, the durability of the particulates should be verified. Responding to this need, this study examines the durability of solid particulates as a heat transfer medium in a closed cycle for concentrated solar power central receiver systems. Specifically, this study analyzes the combination of attrition and sintering of sand with varying temperatures. Attrition is the reduction of a particle’s mass and sintering is a process of fusing two or more particles together to form a larger agglomerate. In a closed cycle, particularly for a concentrated solar power tower, a particle will experience typical temperatures from 600°C to 1000°C. The increase in temperature may change the physical characteristics of the particles and along with any impurities may promote lower softening point bonding. Thus, it is important to investigate particle durability at high temperatures. The experimental procedure used in this investigation involves heating and abrading particulates of a known mass and size distribution to temperatures between 600°C and 1000°C, and also at 25°C to observe attrition only. The testing is conducted using a specially designed experimental apparatus described below. The heated particulates are contained in a metal cylinder. Inside the cylinder is another cylinder made of a porous silicon carbide foam. As the temperature is held constant, the particulate sample is rotated 180 degrees around a horizontal axis every 15 seconds from a low position to a higher position so that the particulates fall and abrade against each other. This process is repeated for a known number of cycles (many thousands). Then the resulting particulate size distribution is measured to determine the amount of attrition and sintering occurred during the experiment. The particulates tested are various types of sand with varying mean diameters and composition, along with a ceramic particulate similar to hydraulic fracturing proppants. Sample composition, sample size distribution, and temperature will be used to establish parameters for rates of attrition and sintering. These rates will be used to predict the behavior of particulates in a concentrated solar power tower closed cycle.

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Study on Optimized Dispatch and Operation Strategies for Heliostat Fields in a Concentrated Solar Power Tower Plant

Energies ◽

10.3390/en12234544 ◽

2019 ◽

Vol 12 (23) ◽

pp. 4544 ◽

Cited By ~ 1

Author(s):

You ◽

Yu ◽

Wang ◽

Sun

Keyword(s):

Flux Distribution ◽

Solar Power ◽

Focal Point ◽

Solar Flux ◽

Small Scale ◽

Concentrated Solar Power ◽

Point Selection ◽

Coupling System ◽

Grouping Method ◽

Solar Power Tower

Concerning solar flux densities during the operation of a concentrated solar power tower plant, their uneven distribution on a central receiver not only leads to abrupt variations of thermal gradient on the receiver surface but also makes it possible for the receiver to break down. Specific to such problems, a “concentrating-receiver” coupling system of a 1 MWe concentrated solar power tower plant in Yanqing was selected as the research object. On this basis, a spliced heliostat model was firstly established in this paper. The model was used to investigate solar flux distribution on the receiver surface. Considering that heliostats in different positions make diverse contributions to receiver surface energy and the incidence cosines of adjacent heliostats are similar to each other, a new grouping method for heliostat fields was subsequently proposed; moreover, focal point selection criteria were designed for the receiver surface according to solar spot sizes. Finally, an optimized dispatch and operation strategy was established based on the genetic algorithm for the heliostat field. Therefore, a standard deviation of solar flux distribution can be minimized. To verify the reliability of the established model and the proposed strategy, a small-scale heliostat field was adopted to check the simulation results by means of experiments. It has been demonstrated that a heliostat field subjected to optimized dispatch makes solar flux densities distribute more uniformly on the receiver surface. Hence, the safe and steady operation of the receiver is guaranteed.

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Corrosion testing of diffusion-coated steel in molten salt for concentrated solar power tower systems

Surface and Coatings Technology ◽

10.1016/j.surfcoat.2018.08.097 ◽

2018 ◽

Vol 354 ◽

pp. 46-55 ◽

Cited By ~ 7

Author(s):

D. Fähsing ◽

C. Oskay ◽

T.M. Meißner ◽

M.C. Galetz

Keyword(s):

Molten Salt ◽

Solar Power ◽

Corrosion Testing ◽

Coated Steel ◽

Concentrated Solar Power ◽

Solar Power Tower

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CSP (Concentrated Solar Power) - Tower Solar Thermal Desalination Plant

American Journal of Modern Energy ◽

10.11648/j.ajme.20200602.11 ◽

2020 ◽

Vol 6 (2) ◽

pp. 51

Author(s):

Huseyin Murat Cekirge ◽

Serdar Eser Erturan ◽

Richard Stanley Thorsen

Keyword(s):

Solar Power ◽

Solar Thermal ◽

Concentrated Solar Power ◽

Desalination Plant ◽

Thermal Desalination ◽

Solar Power Tower

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Dynamic Simulation of a 1MWe Concentrated Solar Power Tower Plant System with Dymola®

Energy Procedia ◽

10.1016/j.egypro.2014.03.168 ◽

2014 ◽

Vol 49 ◽

pp. 1592-1602 ◽

Cited By ~ 8

Author(s):

J.B. Zhang ◽

J.C. Valle-Marcos ◽

B. El-Hefni ◽

Z.F. Wang ◽

G.F. Chen ◽

...

Keyword(s):

Dynamic Simulation ◽

Solar Power ◽

Concentrated Solar Power ◽

Plant System ◽

Solar Power Tower

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Performance and Economic Analysis of Concentrated Solar Power Generation for Pakistan

Processes ◽

10.3390/pr7090575 ◽

2019 ◽

Vol 7 (9) ◽

pp. 575 ◽

Cited By ~ 6

Author(s):

Soomro ◽

Mengal ◽

Memon ◽

Khan ◽

Shafiq ◽

...

Keyword(s):

Energy Production ◽

Solar Power ◽

Renewable Energy Sources ◽

Supply And Demand ◽

Air Cooling ◽

Concentrated Solar Power ◽

Cost Of Energy ◽

Solar Power Tower ◽

Economic Analyses ◽

Solar Resource

In Pakistan, the utilization of renewable energy sources is increasing in order to reduce the electricity supply and demand gap. However, concentrated solar power (CSP) generation has not been considered in the country even though it has gained considerable attention worldwide. This study, as such, investigates the potential, performance, and economic analyses of four CSP technologies for different locations in Pakistan. Initially, an assessment of CSP sites, including solar resource, land, and water availability, was undertaken. Then, performance simulations of CSP technologies for four different locations of Pakistan, namely Quetta, Hyderabad, Multan, and Peshawar, were examined. For all cases, highest energy production was achieved in summers and lowest in winters, and CSP plants with evaporative cooling were found to be efficient compared to air cooling. The results also revealed that the Quetta and Hyderabad regions were promising for CSP development while parabolic tough (PT) and solar power tower (SPT) were the suitable CSP technologies for these regions. Specifically, the SPT plant with air cooling could be a favorable option for energy production in Quetta. Lastly, economic analyses revealed the financial feasibility of CSP plants in Pakistan since the levelized cost of energy is found to be significantly low.

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