Computer-Based Management of Mirror-Washing in Utility-Scale Solar Thermal Plants

2014 ◽  
Author(s):  
Lital Alon ◽  
Gregory Ravikovich ◽  
Matan Mandelbrod ◽  
Udi Eilat ◽  
Zafrir Schop ◽  
...  
Keyword(s):  
Power Plants ◽  
Cost Effective ◽  
Solar Thermal ◽  
Time Saving ◽  
Solar Thermal Collector ◽  
Cleaning Solution ◽  
Computer Based ◽  
Solar Power Plants ◽  
Solar Field ◽  
Utility Scale

BrightSource solar power plants consist of fields of tens of thousands of mirrors, spread across kilometers of open areas. These huge mirrors are in constant motion, reflecting the sun’s rays on to the solar thermal collector. Maintaining high reflectivity of the mirrors is essential for the solar field’s performance, a task that becomes complex when expanded to encompass the solar field’s features. The solution for mirror cleaning must be efficient, cost-effective, time-saving, and easy to maintain for dozens of years. BrightSource has designed and constructed a system of GPS-based mirror washing machines (MWMs) that are controlled and managed by end-to-end software. The system generates optimized cleaning tasks, positions the mirrors, and efficiently controls the navigation and state of the MWMs with their 25-meter-long extendable cranes. All of these actions together provide an optimal mirror cleaning solution. This article describes the BrightSource cleaning control technology, for example, in the Ivanpah project, the world’s largest solar thermal facility. The Ivanpah solar field includes 173,500 heliostats divided among three solar fields. Each heliostat holds two mirrors of approximately 2.5 × 3.5 meters, all of which require periodic cleaning. Specifically, this article addresses issues such as the following: • The mirror washing machine (MWM) types: truck and tractor-based, and their differing usage in the solar field • Designation and choice of the cleaning area • Estimation of the stopping points in the designated area, and association of the mirrors to clean from each stopping point • Cleaning time optimization: stopping point density, order in which to clean heliostats, and heliostat position during cleaning • Heliostat positioning: opening clear corridors through which the MWM can travel, and setting heliostats in cleaning orientations • Receiving and responding to callback messages from the MWMs, such as cleaning progress and machine faults • Working in the real world: resources shared with the power plant, and recovery from system faults

scholarly journals Capital Cost Assessment of Concentrated Solar Power Plants Based on Supercritical Carbon Dioxide Power Cycles

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Francesco Crespi ◽  
David Sánchez ◽  
Tomás Sánchez ◽  
Gonzalo S. Martínez
Keyword(s):  
Power Plants ◽  
Solar Power ◽  
Cost Effective ◽  
Capital Cost ◽  
Operating Conditions ◽  
Concentrated Solar Power ◽  
Power Cycles ◽  
Solar Power Plants ◽  
Major Equipment ◽  
Solar Field

Previous work by the authors has shown that broader analyses than those typically found in literature (in terms of operating pressures allowed) can yield interesting conclusions with respect to the best candidate cycles for certain applications. This has been tested for the thermodynamic performance (first and second laws) but it can also be applied from an economic standpoint. This second approach is introduced in this work where typical operating conditions for concentrated solar power (CSP) applications (current and future generations of solar tower plants) are considered (750 °C and 30 MPa). For these, the techno-economic performance of each cycle is assessed in order to identify the most cost-effective layout when it comes to the overnight capital cost (OCC). This analysis accounts for the different contributions to the total cost of the plant, including all the major equipment that is usually found in a CSP power plant such as the solar field and thermal energy storage (TES) system. The work is, thus, aimed at providing guidelines to professionals in the area of basic engineering and prefeasibility study of CSP plants who find themselves in the process of selecting a particular power cycle for a new project (set of specifications and boundary conditions).

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.

Mirage in the Making

2012 ◽  
Vol 2 (3) ◽  
pp. 25-44 ◽  
Author(s):  
Peter S. Alagona ◽  
Clinton F. Smith
Keyword(s):  
Renewable Energy ◽  
Environmental History ◽  
Mojave Desert ◽  
Power Plants ◽  
Military Training ◽  
Current Debate ◽  
Cultural Resources ◽  
Solar Power Plants ◽  
Diverse Groups ◽  
Utility Scale

The Mojave Desert in California is undergoing a boom in renewable energy, mostly in the form of utility-scale solar power plants. These projects have met with resistance from diverse groups concerned about impacts on desert landscapes, ecosystems, water resources, archaeological sites, military training exercises, and other natural and cultural resources and land uses. This paper explores the current debate over renewable energy in the Mojave in the context of the region’s broader environmental history. What do Californians want from the Mojave Desert? We conclude that residents of the state want many things from the Mojave, but it remains unclear whether a desert under increasing pressure will be able to supply all of those competing demands.

Test Results and Status of the TOP Alignment System for Parabolic Trough Solar Collectors

2010 ◽  
Author(s):  
Richard B. Diver ◽  
Timothy A. Moss
Keyword(s):  
Power Plants ◽  
Incident Angle ◽  
Cost Effective ◽  
Test Results ◽  
Parabolic Trough ◽  
Performance Improvements ◽  
Alignment System ◽  
Alignment Technique ◽  
Solar Power Plants ◽  
Solar Electricity

Parabolic trough solar power plants produce the lowest cost solar electricity, yet unsubsidized electricity from parabolic trough power plants costs about twice that from conventional sources. To make parabolic trough electricity more competitive, we are developing an innovative approach for rapidly and effectively evaluating the alignment of mirrors in parabolic trough power plants and prescribing corrective actions as needed. The Theoretical Overlay Photographic Collector Alignment Technique (TOPCAT) system could be used during construction, to improve the performance of existing power plants, or for routine maintenance. It is also an enabling technology for higher concentration ratio and lower cost trough solar collector designs needed to make solar electricity more competitive with conventional sources. In this paper a truck-mounted TOPCAT field characterization system is described. Test results from mirror alignment of an LS-3 loop in a commercial parabolic trough power plant in southern California are also presented. The performance improvements were measured using a comparative calorimetric technique which inherently accounts for variations in insolation levels, sun incident angle, and mirror and heat collection element (HCE) glass envelope cleanliness. Measurements indicate a 3.5% increase in thermal performance of an LS-3 loop aligned with the TOPCAT system. Benchmarking results of labor hours and materials show that the TOPCAT system is an extremely cost effective tool for improving the performance of existing parabolic trough power plants.

Development and Characterization of Solar Simulator for Solar Cells

2020 ◽  
Vol 15 (6) ◽  
pp. 720-724
Author(s):  
In Sung Jung ◽  
Jaeho Choi ◽  
Deb Kumar Shah ◽  
M. Shaheer Akhtar
Keyword(s):  
Solar Cells ◽  
Power Plants ◽  
Cost Effective ◽  
Solar Simulator ◽  
Light Emitting ◽  
Continuous Type ◽  
Temporal Instability ◽  
Cell Measurement ◽  
Solar Power Plants ◽  
The One

The solar simulator is crucial instrument to determine the performance of solar cells and modules which are core components of solar power plants. Therefore, a precise performance measurement of solar cells is very important to design a cost effective solar stimulator with high accuracy. This paper proposes the development of a precise and measurable innovative solar simulator technique. The designed solar stimulator is a continuous type for 6 inch solar cell measurement in which a reflector system is added for improving the uniformity of result. In addition, 2∼6 light emitting diodes (LEDs) are attached to the one side of the reflector. For reliable evaluation, the standard measurement of IEC60904-3 was applied and matched the uniformity, temporal instability, and spectrum values under 1000 W/m2 light intensity condition. The uniformity of the solar simulator was recorded to 1.43% by using Al reflector and LED, which was highly comparable to 3.06 before its utilization (without reflector). Thus, designed stimulator improved the temporal instability and spectrum match values, which might be considered as a class A.

Application of solid state transformers in utility scale solar power plants

2014 ◽  
Author(s):  
Nicole C. Foureaux ◽  
Leonardo Adolpho ◽  
Sidelmo Magalhaes Silva ◽  
Jose Antonio de S. Brito ◽  
Braz de J. Cardoso Filho
Keyword(s):  
Solid State ◽  
Power Plants ◽  
Solar Power ◽  
Solid State Transformers ◽  
Solar Power Plants ◽  
Utility Scale

A Review on Experimental and Numerical Investigations on Using Nanofluid in Volumetric Solar Energy Collectors

2014 ◽  
Author(s):  
Siamak Mirmasoumi ◽  
Mohammad Pourgol-Mohammad
Keyword(s):  
Heat Transfer ◽  
Power Plants ◽  
Radiant Energy ◽  
Solar Thermal ◽  
Working Fluid ◽  
Steam Generation ◽  
Solar Thermal Energy ◽  
Solar Absorption ◽  
Advantages And Disadvantages ◽  
Solar Power Plants

By a simple research in the scholarly articles, it can be realized that the tendency to using solar thermal energy has risen in the recent years due to its many reasonable advantages. In conventional solar thermal systems, HTFs (Heat Transfer Fluids) are pumped through the piping of a solar collector and after absorbing the solar radiant energy conveys it to water to make steam. No need to say that this method contains some losses via all methods of heat transfer. To solve this problem, researchers have shown that with direct steam generation, in which working fluid directly absorbs solar thermal and becomes vapor, solar power plants have the potential to be more productive. However, the aforesaid conventional HTFs don’t have efficient enough thermal properties and need to be improved. For this reason using nanofluid has become to some extent popular in heat transfer facilities like solar thermal collectors. In the present study, we are going to identify the advantages and disadvantages of using nanoparticles in direct solar absorption systems (DSASs). To achieve this, a general review on the experimental and numerical studies in this field is done. Additionally some of the most effective particles for such a special case, in which particles should have good radiative characteristics, are introduced. Finally, after discussion about the highlighted challenges of using nanofluids in DSASs, some helpful suggestions to overcome these problems will be presented.

Reducing the Number of Turbine Starts in Concentrating Solar Power Plants Through the Integration of Thermal Energy Storage

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
Rafael Guédez ◽  
James Spelling ◽  
Björn Laumert
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Power Plants ◽  
Thermal Power ◽  
Solar Thermal ◽  
Annual Number ◽  
Thermal Power Plants ◽  
Solar Thermal Power ◽  
Solar Power Plants

The operation of steam turbine units in solar thermal power plants is very different than in conventional base-load plants. Due to the variability of the solar resource, much higher frequencies of plant start-ups are encountered. This study provides an insight to the influence of thermal energy storage (TES) integration on the typical cycling operation of solar thermal power plants. It is demonstrated that the integration of storage leads to significant reductions in the annual number of turbine starts and is thus beneficial to the turbine lifetime. At the same time, the effects of storage integration on the electricity costs are analyzed to ensure that the designs remain economically competitive. Large storage capacities, can allow the plant to be shifted from a daily starting regime to one where less than 20 plant starts occur annually. Additionally, the concept of equivalent operating hours (EOHs) is used to further analyze the direct impact of storage integration on the maintenance planning of the turbine units.

Ultimate Trough: The New Parabolic Trough Collector Generation for Large Scale Solar Thermal Power Plants

2011 ◽  
Author(s):  
Klaus-Ju¨rgen Riffelmann ◽  
Daniela Graf ◽  
Paul Nava
Keyword(s):  
Power Plants ◽  
Large Scale ◽  
Thermal Power ◽  
Thermal Storage ◽  
Solar Thermal ◽  
Thermal Power Plants ◽  
Large Power ◽  
Solar Thermal Power ◽  
Aperture Width ◽  
Solar Field

From 1984 to 1992, the first commercial solar thermal power plants — SEGS I to IX — were built in the Californian Mojave desert. The first generation of trough collectors (LS1) used in SEGS I showed an aperture area of about 120 m2 (1’292 ft2), having an aperture width of 2.5 m (8.2 ft). With the second generation collector (LS2), used in SEGS II to VI, the aperture width was doubled to 5 m (16.4 ft). The third generation (LS3) has been increased regarding width (5.76 m or 18.9 ft) and length (96 m or 315 ft) to about 550 m2 (5’920 ft2) aperture. It was used in the last SEGS plants VIII and IX, those plants having a capacity of 80 MW each. After more than 10 years stagnancy, several commercial plants in the US (the 64 MW Nevada Solar One project) and Spain (the ANDASOL projects, 50 MW each with 8 h thermal storage) started operation in 2007/2008. New collectors have been developed, but all are showing similar dimensions as either the LS2 or the LS3 collector. One reason for this is the limited availability of key components, mainly the parabolic shaped mirrors and heat collection elements. However, in order to reduce cost, solar power projects are getting larger and larger. Several projects in the range of 250 MW, with and without thermal storage system, are going to start construction in 2011, requiring solar field sizes of 1 to 2.5 Million m2. FLABEG, market leader of parabolic shaped mirrors and e.g. mirror supplier for all SEGS plants and most of the Spanish plants, has started the development of a new collector generation to serve the urgent market needs: lower cost and improved suitability for large solar fields. The new generation will utilize accordingly larger reflector panels and heat collection elements attended by advanced design, installation methods and control systems at the same time. The so-called ‘Ultimate Trough’ collector is showing an aperture area of 1’667 m2 (17’944 ft2), with an aperture width of 7.5 m (24.6 ft). Some design features are presented in this paper, showing how the new and huge dimensions could be realized without compromising stiffness, and bending of the support structure and improving the optical performance at the same time. Solar field layouts for large power plants are presented, and solar field cost savings in the range of 25% are disclosed.

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