scholarly journals Integration of Soiling-Rate Measurements and Cleaning Strategies in Yield Analysis of Parabolic Trough Plants

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Fabian Wolfertstetter ◽  
Stefan Wilbert ◽  
Jürgen Dersch ◽  
Simon Dieckmann ◽  
Robert Pitz-Paal ◽  
...  
Keyword(s):  
Power Plants ◽  
Thermal Power ◽  
Time Dependent ◽  
Analysis Software ◽  
Parabolic Trough ◽  
Fully Integrated ◽  
Yield Analysis ◽  
Dependent Parameter ◽  
One Year ◽  
Solar Field

The issue of reflector soiling becomes more important as concentrating solar thermal power plants (CSP) are being implemented at sites subject to high dust loads. In an operational power plant, a trade-off between reducing cleaning costs and cleaning related collector availability on the one hand and keeping the solar field cleanliness (ξfield) high to minimize soiling induced losses on the other hand must be found. The common yield analysis software packages system advisor model (SAM) and greenius only allow the input of a constant mean ξfield and constant cleaning costs. This oversimplifies real conditions because soiling is a highly time-dependent parameter and operators might adjust cleaning activities depending on factors such as soiling rate and irradiance. In this study, time-dependent soiling and cleaning data are used for modeling the yield of two parabolic trough plant configurations at two sites in Spain and Morocco. We apply a one-year soiling rate dataset in daily resolution measured with the tracking cleanliness sensor (TraCS). We use this as a basis to model the daily evolution of the cleanliness of each collector of a solar field resulting from the application of various cleaning strategies (CS). The thus obtained daily average ξfield is used to modify the inputs to the yield analysis software greenius. The cleaning costs for each CS are subtracted from the project's financial output parameters to accurately predict the yield of a CSP project over its lifetime. The profits obtained with different CSs are compared in a parameter variation analysis for two sites and the economically best CS is identified. The profit can be increased by more than 2.6% by the application of the best strategy relative to a reference strategy that uses a constant cleaning frequency. The error in profit calculated with constant soiling and cleaning parameters compared to the simulation with variable soiling and cleaning can be as high as 9.4%. With the presented method, temporally variable soiling rates and CS can be fully integrated to CSP yield analysis software, significantly increasing its accuracy. It can be used to determine optimum cleaning parameters.

scholarly journals Modeling and Hourly Time-Scale Characterization of the Main Energy Parameters of Parabolic-Trough Solar Thermal Power Plants Using a Simplified Quasi-Dynamic Model

Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 221
Author(s):  
Ignacio Arias ◽  
Eduardo Zarza ◽  
Loreto Valenzuela ◽  
Manuel Pérez-García ◽  
José Alfonso Romero Ramos ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Power Plants ◽  
Thermal Power ◽  
Thermal Power Plants ◽  
Parabolic Trough ◽  
Solar Thermal Power ◽  
Simulation Results ◽  
Solar Field ◽  
The Mathematical Model

A simplified mathematical model of parabolic-trough solar thermal power plants, which allow one to carry out an energetic characterization of the main thermal parameters that influence the solar field performance, was evaluated through a comparison of simulation results. Two geographical locations were selected to evaluate the mathematical model proposed in this work—one in each hemisphere—and design considerations according with the practical/operational experience were taken. Furthermore, independent simulations were performed using the System Advisor Model (SAM) software, their results were compared with those obtained by the simplified model. According with the above, the mathematical model allows one to carry out simulations with a high degree of flexibility and adaptability, in which the equations that allow the plant to be energetically characterized are composed of a series of logical conditions that help identify boundary conditions between dawn and sunset, direct normal irradiance transients, and when the thermal energy storage system must compensate the solar field energy deficits to maintain the full load operation of the plant. Due to the above, the developed model allows one to obtain satisfactory simulation results; referring to the net electric power production, this model provides results in both hemispheres with a relative percentage error in the range of [0.28–8.38%] compared with the results obtained with the SAM, with mean square values of 4.57% and 4.21% for sites 1 and 2, respectively.

Review of Geothermal and Solar Thermal Power Plants and a Comparative Design Analysis

2015 ◽  
Author(s):  
Roberto Venegas ◽  
Sarada Kuravi ◽  
Krishna Kota ◽  
Troy Nguyen ◽  
Mary McCay
Keyword(s):  
Power Plants ◽  
Thermal Power ◽  
Combined Cycle ◽  
Solar Thermal ◽  
Site Location ◽  
Parabolic Trough ◽  
Geothermal Resources ◽  
Cost Of Energy ◽  
Energy Conversion Systems ◽  
One Year

Thermodynamics indicates that the lower the temperature of a resource, the less energy that could be extracted from it due to lower maximum thermal efficiency. Geothermal resources exist in varying temperatures. The lowest ones (around 120°C), are too small for economic power production. On the other hand, concentrating solar power (CSP) can achieve high temperatures during the day (from 350 to 550°C, based on a Parabolic Trough CSP plant [1]) but once the sun is not shining, that temperature is reduced drastically. Transition to renewable energy systems is an environmentally friendly and potentially rewarding economic decision that society can make nowadays. This paper briefly reviews geothermal and solar thermal based plants in terms of energy growth or decay from one year to another (2012–2013). In addition, an example site location is chosen and the performance of both these types of power plants is analyzed in terms of capacity factor, Thermal Energy Storage (TES) hours, solar multiple, area requirement and Levelized Cost of Energy (LCOE) for a given set of environmental conditions. This analysis is performed using the System Advisor Model (SAM), on which simulation of parabolic trough, power tower, linear Fresnel, dish Stirling and geothermal (binary cycle) energy conversion systems are considered. At the same time, the analysis discussed will take place in a further study which will include economic viability for the two technologies running under the same combined cycle.

Comparison of Two Linear Collectors in Solar Thermal Plants: Parabolic Trough vs Fresnel

2011 ◽  
Author(s):  
A. Giostri ◽  
M. Binotti ◽  
P. Silva ◽  
E. Macchi ◽  
G. Manzolini
Keyword(s):  
Power Plants ◽  
Thermal Power ◽  
Solar Thermal ◽  
Heat Transfer Fluid ◽  
Steam Generation ◽  
Parabolic Trough ◽  
Research Activity ◽  
Optical Efficiency ◽  
Synthetic Oil ◽  
Yearly Average

Parabolic trough can be considered the state of the art for solar thermal power plants thanks to the almost 30 years experience gained in SEGS and, recently, Nevada Solar One plants in US and Andasol plants in Spain. One of the major issues that limits the wide diffusion of this technology is the high investment cost of the solar field and, particularly, of the solar collector. For this reason, since several years research activity has been trying to develop new solutions with the aim of cost reduction. This work compares commercial Fresnel technology with conventional parabolic trough plant based on synthetic oil as heat transfer fluid at nominal conditions and evaluates yearly average performances. In both technologies, no thermal storage system is considered. In addition, for Fresnel, a Direct Steam Generation (DSG) case is investigated. Performances are calculated by a commercial code, Thermoflex®, with dedicated component to evaluate solar plant. Results will show that, at nominal conditions, Fresnel technology have an optical efficiency of 67% which is lower than 75% of parabolic trough. Calculated net electric efficiency is about 19.25%, while parabolic trough technology achieves 23.6%. In off-design conditions, the gap between Fresnel and parabolic trough increases because the former is significantly affected by high radiation incident angles. The calculated sun-to-electric annual average efficiency for Fresnel plant is 10.2%, consequence of the average optical efficiency of 38.8%, while parabolic trough achieve an overall efficiency of 16%, with an optical one of 52.7%. An additional case with Fresnel collector and synthetic oil outlines differences among investigated cases. Finally, because part of performance difference between PT and Fresnel is simple due to different definitions, additional indexes are introduced in order to make a consistent comparison.

Annual Yield Analysis of Solar Tower Power Plants With GREENIUS

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Jürgen Dersch ◽  
Peter Schwarzbözl ◽  
Timo Richert
Keyword(s):  
Renewable Energy ◽  
Power Plants ◽  
Software Tool ◽  
Parabolic Trough ◽  
Concentrating Solar Power ◽  
Solar Field ◽  
Performance Calculation ◽  
Design Power ◽  
Energy Plants ◽  
Renewable Energy Plants

An existing software tool for annual performance calculation of concentrating solar power and other renewable energy plants has been extended to enable the simulation of solar tower power plants. The methodology used is shown and a demonstrative example of a 50 MWe tower plant in southern Spain is given. The influence of design power and latitude on solar field layout is discussed. Furthermore, a comparison of the tower plant with a 50 MWe parabolic trough and a Linear Fresnel plant at the same site is given.

The DISS Project: Direct Steam Generation in Parabolic Trough Systems. Operation and Maintenance Experience and Update on Project Status

2002 ◽  
Vol 124 (2) ◽  
pp. 126-133 ◽  
Author(s):  
Eduardo Zarza ◽  
Loreto Valenzuela ◽  
Javier Leo´n ◽  
H.-Dieter Weyers ◽  
Martin Eickhoff ◽  
...  
Keyword(s):  
Power Plants ◽  
New Technology ◽  
Thermal Power ◽  
Test Facility ◽  
Steam Generation ◽  
Parabolic Trough ◽  
Solar Thermal Power ◽  
Operation And Maintenance ◽  
Direct Steam ◽  
New Generation

The DISS (DIrect Solar Steam) project is a complete R+TD program aimed at developing a new generation of solar thermal power plants with direct steam generation (DSG) in the absorber tubes of parabolic trough collectors. During the first phase of the project (1996-1998), a life-size test facility was implemented at the Plataforma Solar de Almerı´a (PSA) to investigate the basic DSG processes under real solar conditions and evaluate the unanswered technical questions concerning this new technology. This paper updates DISS project status and explains O&M-related experience (e.g., main problems faced and solutions applied) with the PSA DISS test facility since January 1999.

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