Parabolic Trough Collector Power Plant Research Articles

Effects of Thermal Performance Enhancement on PTC Downsizing With Emphasis on Cost Savings and Commercial Feasibility: An Extended Evaluation Criterion

ABSTRACTThis study proposes a new comparative analysis and introduces a new criterion for evaluating the size reduction of heat exchangers, particularly relevant in the context of parabolic trough receivers. Various innovative receivers from the literature, employing different enhancement techniques, were compared with the conventional straight receiver. On the basis of the principle of similarity and using a previously validated one‐dimensional mathematical model and numerical code, a parametric analysis was used to estimate reduction ratios and sizes for different solar receivers. For well‐defined receiver geometries, the main results reveal consistent reduction ratios of around 99.7% and 93.53% for helical screw‐tape and wavy receivers, respectively. This translates to size reductions of approximately 0.3 and 6.5 m compared with a 100‐m‐long conventional straight receiver, respectively. By integrating the ratio and the performance evaluation criterion (PEC) into a unified metric mPEC = PEC/, which accounts for both effectiveness and size reduction, a new classification of receivers is derived, closely aligning with that obtained by the ratio. In addition, a rebalancing analysis of the increased load loss is conducted based on this ratio. It suggests that in a scenario where the wavy receiver replaces the conventional straight receiver in operation, there would be no need to increase pumping power, as its reduced size compensates for the increased pressure drop. This scenario was used to assess the economic impact of a parabolic trough collector power plant in Hassi R'mel (Algerian Sahara). Without any additional components to boost performance, the adoption of the wavy receiver led to significant gains in terms of useful surface area, cost, and length, resulting in savings of over €3.02 million for this 30 MW solar energy field.

Energy analysis of a hybrid parabolic trough collector with a steam power plant in Jordan

In this work, a hybrid system consisting of a parabolic trough collector and a steam power plant is proposed. The effect of utilizing the parabolic trough collector on improving the performance of the plant and reducing fuel consumption has been studied experimentally. This study was implemented on a lab scale hybrid energy system consisting of a parabolic trough collector unit incorporated into a biomass-oil shale fired steam power plant during startup conditions. To determine the performance of this lab-scale hybrid system, the efficiency of the parabolic trough collector standalone system has been measured and the flow rate of the system has been tuned to 0.31 L/min to obtain an efficiency of 10.2%. The biomass-oil shale fired power plant worked with superheated steam at 377 °C temperature and 0.6 MPa pressure. The thermal efficiency of the power plant was 12.6% with net output power of 6.3 kW without using the parabolic trough collector unit. It was found that the performance of the hybrid system has shown better efficiency than the standalone biomass fired power plant with the same fuel mixture ratio and steam flowrate. The fuel mixture consumed in the hybrid system decreased by 62.0% at starting up condition. This result may be extended to steady-state operating conditions by increasing the number of parabolic trough collector units utilized. Furthermore, the overall thermal efficiency of the hybrid parabolic trough collector power plant system may reach 33.3% during steady-state operation if 48 parabolic trough collector similar units were used. These parabolic trough collector units should be arranged in three parallel rows, each row of 16 units in series.

Thermodynamic Analysis of a Parabolic Trough Collector (PTC) operating with gas-phase nanofluids

Parabolic Trough Collectors (PTC) are the most developed and established technology among the concentrated solar power systems. However, the majority of the PTC power plants currently in operation uses synthetic oils or molten salts as heat transfer fluids (HTF), with a limited operating temperature range. To operate at higher temperatures, the use of pressurized gases as working fluid has been recently proposed in several studies. However, in this case a large pumping power is required. In this work, the use of gas-solid suspensions in a commercial PTC has been analyzed. A thermodynamic analysis has been performed to investigate the effect of three different gas-solid suspensions: Argon-Al2O3, Carbon Dioxide-Al2O3 and Air-Al2O3. The performance of these gas-phase nanofluids has been compared to the use of pure gases. Power output, pumping power, outlet fluid temperature and global efficiency of the parabolic trough system have been determined. The analysis shows a substantial decrease of the pumping power. Thanks to this advantage, the use of gas-phase nanofluids in parabolic trough collectors could represent an interesting possibility.

A theoretical study of molten carbonate fuel cell combined with a solar power plant and Cu–Cl thermochemical cycle based on techno-economic analysis

A novel power and hydrogen coproduction system is designed and analyzed from energetic and economic point of view. Power is simultaneously produced from parabolic trough collector power plant and molten carbonate fuel cell whereas hydrogen is generated in a three-steps Cu–Cl thermochemical cycle. The key component of the system is the molten carbonate fuel cell that provides heat to others (Cu–Cl thermochemical cycle and steam accumulator). A mathematic model is developed for energetic and economic analyses. A parametric study is performed to assess the impact of some parameters on the system performance. From calculations, it is deduced that electric energy from fuel cell, solar plant and output hydrogen mass are respectively 578 GWh, 25 GWh and 306 tons. The overall energy efficiency of the proposed plants is 46.80 % and its LCOE is 7.64 c€/kWh. The use of MCFC waste heat allows increasing the solar power plant efficiency by 2.15 % and reducing the annual hydrogen consumption by 3 %. Parametric analysis shows that the amount of heat recovery impacts the energy efficiency of fuel cell and Cu–Cl cycle. Also, current density is a key parameter that influences the system efficiency.

Dynamic 6E analysis of direct steam generator solar parabolic trough collector power plant with thermal energy storage

The present study discusses the generation of electricity through solar Rankine cycle thermal power plants by direct steam-generating collectors. This solar thermal power plant is modeled on the production of a net power of 50 MW. Modeling has been done by coding in the MATLAB environment and weather conditions of Qom city. A two-tank indirect heat storage system has been used to prevent the power generation cycle from failing when there is no solar energy. The design of a two-tank heat storage system to store the heat generated by direct steam generator collectors is the novelty of this research. Power generation continues in the discharge mode until the heat stored in the heat storage system is finished. An auxiliary boiler must also be used in the discharge mode to bring the steam condition to the desired condition for the high-pressure steam turbine inlet. In previous studies, analyses have been performed for the cycle without a heat storage tank and steady state conditions. For the first time in this research, this power plant's design is done transiently, hour by hour throughout the year, and reported. The heat storage system is designed to generate 6 h of 50 MW of electricity in the sun's absence. But according to the transient analysis, the amount of heat storage varies from day to day depending on the daylight hours of the same day, and therefore the amount of discharge hours per day is different. For each component of the power generation cycle, exergy, exergoeconomic, exergoenvironmental, emergoeconomic, and emergoenvironmental analysis as 6E analysis have been performed. The results are reported transiently hour by hour throughout the year, as well as the monthly average. The results showed that improving the boiler to reduce irreversibility and exergy destruction is an important matter that can improve both the environment and the plant economically. As a result of exergy analysis, the average monthly total exergy efficiency of the power plant varies between 70 and 85% during the year. The average monthly exergy efficiency of the solar field in the four months of May, June, July, and August is about 39 to 40%.

Comparative analysis of economic aspects of concentrated solar power versus photovoltaic in Afghanistan - Case study: Kang district, Nimruz

This paper analyzes the impacts of whole solar energy technologies on the economic situation of Afghanistan. Details and positive effects of solar mini-grids which are implemented through the Citizens’ Charter National Priority Program CCNPP in the rural areas of Afghanistan are given as samples of solar energy projects in Afghanistan. The result of this analysis then compared with the fossil fuel electricity that people use in the rural areas of Afghanistan based on the economic effects. The Levelized Cost of Energy (LCOE) for electricity generated through the diesel generator is estimated to be 29 ¢/kWh, which is 3.16 times higher than the cost of electricity produced via photovoltaic (PV) in 9.17 ¢/kWh. The potential for solar thermal as a recently boomed technology in the world is also studied with regard to the climate, economy, and security situation of Afghanistan. The country with 300 sunny days in a year has 1900-2000 kWh/m2 potential of producing electricity through the Concentrated Solar Power (CSP) technology. Using Multi-Criteria Decision Analysis (MCDA) the Parabolic Trough Collector (PTC) is selected as an optimal type of CSP in Afghanistan and a 3.5 MW PTC power plant is simulated via the System Advisor Model (SAM) software. The result of this simulation shows that this novel technology in Afghanistan needs more time and efforts to set as a secure approach of energy

Determination of design parameters to minimize LCOE, for a 1 MWe CSP plant in different sites

The levelized cost of energy (LCOE) from a parabolic trough collector power plant is influenced directly by its design parameters. In the present paper, the impact of five design parameters (solar multiple, direct normal irradiation, cycle efficiency, mirrors efficiency and absorber efficiency) is investigated in order to minimize the LCOE for a 1 MWe power plant. The artificial neural networks (ANN) and the response surface methodology (RSM) are used to model the LCOE as function of these five parameters. The methodology is applied to six cities of Morocco, and the results show that the ANN is the best model to predict the LCOE using the best topology of 5-7-1 neurons. This structure allows satisfactory prediction of LCOE obtained with Mean Absolute Error (MAE) of about 2% and Maximum Error (ME) of 9%. A minimal cost of 8.74 cents is obtained for Tata city with a direct normal irradiation of 7.09 Wh/m2/day, by coupling ANN model to desirability function. The optimal plant design point is 1.94 for the solar multiple, 20.88% for the cycle efficiency, 0.8673 for the mirror efficiency and 0.8537 for the absorber efficiency.

Development and assessment of integrating parabolic trough collectors with gas turbine trigeneration system for producing electricity, chilled water, and freshwater

The main objective of the present work is to investigate the possible modifications of a gas turbine trigeneration plant via integrating it with a parabolic trough collector (PTC) technology. This plant produces 45461 m3/day of freshwater and 2300 kg/s of chilled water in addition to producing 360 MWe of electricity (the steam turbines yield 110 MWe). The annual performance of an integrated solar gas turbine trigeneration power plant (ISGTPP) with different sizes of gas turbine and solar collector's area have been examined using Thermoflex software under Al-Hodeidah (Yemen) weather conditions. This study revealed that the ISGTPP results in a minor increase in levelized electricity cost (LEC) compared to the conventional trigeneration plant, nevertheless it reduces the LEC by 62–71.5% relative to the fully-solar-powered PTC power plants. Moreover, the study identified the configuration of ISGTPP with a gas turbine of 130 MWe capacity and 39.7 ha of PTC's total aperture area as the most optimal engine configuration. It reduces the annual CO2 emissions by 385 k-tonne (30.2%) in comparing with that emitted by the reference plant with a gas turbine of 250 MWe size and 100 k-tonne (10%) compared with that emitted by the corresponding conventional plant with 130 MWe size.

Analysis of an innovative direct steam generation-based parabolic trough collector plant hybridized with a biomass boiler

Direct steam generation (DSG) is the process by which steam is directly produced in parabolic trough fields and supplied to a power block. This process simplifies parabolic trough plants and improves cost effectiveness by increasing the permissible temperature of the working fluid. Similar to all solar-based technologies, thermal energy storage is needed to overcome the intermittent nature of solar. In the present work, an innovative DSG-based parabolic trough collector (PTC) plant hybridized with a biomass boiler is proposed and analyzed in detail. Two additional configurations comprising indirect steam generation PTC plants were also analyzed to compare their energy and exergy performance. To consider a wide range of operation, the share of biomass input to the hybridized system is varied. Energy and exergy analyses of DSG are conducted and compared with an existing indirect steam generation PTC power plants such as Andasol. The analyses are conducted on a 50 MW regenerative reheat Rankine cycle. The results obtained indicate that the proposed DSG-based PTC plant is able to increase the overall system efficiency by 3% in comparison with indirect steam generation when linked to a biomass boiler that supplies 50% of the energy.

Modelling and simulation of a novel Electrical Energy Storage (EES) Receiver for Solar Parabolic Trough Collector (PTC) power plants

In this paper, the mathematical modelling of a novel Electrical Energy Storage (EES) Receiver for Solar Parabolic Trough Collector (PTC) is presented. The EES receiver is essentially a Heat Collecting Element (HCE) with built in storage in the form of thermal batteries such as the Sodium Sulphur (NaS) battery. The conceptual design and mathematical models describing the operation of the receiver are presented along with important results of model validation. When held under adiabatic conditions (a primary indicator of model validity), results were highly consistent with established PTC, models and with National Renewable Energy Laboratory (NREL, USA) experimental data for existing SCHOTT PTR-70 and Solel UVAC3 receiver tubes, currently being used in existing PTC power plants.

Energetic Comparison of Linear Fresnel and Parabolic Trough Collector Systems

In recent years, linear Fresnel (LF) collector systems have been developed as a technical alternative to parabolic trough (PT) collector systems. While in the past, LF systems focused on low- and medium-temperature applications, today, LF systems are equipped with vacuum receivers and, therefore, can be operated with similar operating parameters as PT systems. Papers about the technical and economical comparison of specific PT and LF systems have already been published (Dersch et al., 2009, "Comparison of Linear Fresnel and Parabolic Trough Collecor Systems—System Analysis to Determine Break-Even Costs of Linear Fresnel Collectors," Proceedings of the 15th International SolarPACES Symposium, Berlin; Giostri et al. 2011, "Comparison of Two Linear Collectors in Solar Thermal Plants: Parabolic Trough vs. Fresnel," ASME 2011 5th International Conference on Energy Sustainability, Washington, DC; and Morin et al., 2012, "Comparison of Linear Fresnel and Parabolic Trough Collector Power Plants," Sol. Energy, 86(1), pp. 1–12). However, the present paper focuses on the systematic differences in optical and thermodynamic performance and the impact on the economic figures. In a first step the optical performance of typical PT and LF solar fields (SFs) has been examined, showing the differences during the course of the day and annually. Furthermore, the thermodynamic performance, depending on the operating temperature, has been compared. In a second step, the annual electricity yield of typical PT and LF plants has been examined. Solar Salt has been chosen as the heat transfer fluid. Both systems utilize the same power block (PB) and storage type. Solar field size, storage capacity, and PB electrical power are variable, while all examined configurations achieve the same annual electricity yield. As expected for molten salt systems, both systems are the most cost-effective with large storage capacities. The lower thermodynamic performance of the LF system requires a larger SF and lower specific SF costs in order to be competitive. Assuming specific PT field costs of 300 €/m2 aperture, the break-even costs of the LF system with Solar Salt range between 202 and 235 €/m2, depending on the site and storage capacity. In order to confirm the major statements, within a sensitivity analysis, it is shown that a variation of SF and storage costs does not have a significant impact on the relative break-even costs of the LF system.

Feasibility analysis of megawatt scale solar thermal power plants

In this article, feasibility analysis of solar thermal power plants is carried out for large scale power generation. Three different configurations of concentrating solar power technologies such as linear Fresnel reflector collector (LFRC), parabolic trough collector (PTC), and power tower (PT) are analyzed for power generation in stand-alone mode and various plant capacities such as 1 MWe, 5 MWe, 10 MWe, 30 MWe, and 50 MWe. The maximum achievable steam conditions in LFRC system has been considered for all the power plant capacities as 55 bar and 270 °C. In case of parabolic trough and power tower, the steam parameters have been considered as 60 bar, 370 °C for 1 MWe, 65 bar, 400 °C for 5 MWe, 65 bar, 410 °C for 10 MWe, 100 bar, 410 °C for 30 MWe, and 100 bar, 410 °C for 50 MWe. The feasibility of stand-alone solar power plants (SASPPs) is compared with coal fired power plant (CFPP) and solar aided coal fired power plant (SACFPP). The feasibility analysis in terms of performance and levelised electricity cost (LEC) is carried out for various technologies with capacities. It is observed that the LFRC power plants are relatively less efficient than others due to lower optical and thermal efficiency. The energy and exergy efficiencies of a 50 MWe LFRC power plant are found as 12.17% and 17.21%, respectively. The efficiency of 50 MWe solar PTC power plants is found as 23.16% which is higher than other technologies. The net exergy efficiency of PTC power plants increases from 23.14% to 32.76% for the plant capacity increases from 1 MWe to 50 MWe. It is observed that the exergy efficiency decreases from 22.57% to 19.65% as plant capacity increases from 1 MWe to 10 MWe due to shading and blocking for PT power plants and then increases to maximum of 23.33% for the 50 MWe power plant. The exergy efficiencies of 50 MWe CFPP and SACFPP have been estimated as 28.17% and 28.21%, respectively. The environmental benefits of stand-alone solar power plants are estimated in terms of CO2 mitigations and compared with CFPP. The LEC of CFPP, SACFPP, and SASPP is found as INR 3.56/kWh, INR 3.60/kWh, and INR 8.48/kWh, respectively. The discounted payback period, benefit-to-cost ratio, and net present value of all the power plants are also estimated.

Probabilistic modeling of a parabolic trough collector power plant – An uncertainty and sensitivity analysis

In this work, an uncertainty and sensitivity analysis for the annual performance of a parabolic trough collector plant based on a probabilistic modeling approach of the solar-to-thermal energy conversion process has been accomplished. Realistic probability functions have been assigned to the most relevant solar field performance parameters. The Latin Hypercube sampling method has been used to create equal probable parameter combinations. The so obtained sample matrix has been used to run multiple annual electricity yield simulations in SimulCET, a validated parabolic trough collector plant simulation software, developed by the National Renewable Energy Center (CENER) in Spain García-Barberena et al., 2012. This procedure has led to a representative distribution for the annual plant performance, given the uncertainty in the input data. For this study the parabolic trough power plant model has been run in solar driven operation mode, without the use of thermal storage or fossil fuel back up. While being aware of the great influence of the solar irradiation on the power plant performance, only one single reference meteorological year has been used as solar input data. This has been done in order to emphasize the influence of technical design- as well as solar field maintenance parameters, factors that can be controlled or affected by mankind. In order to assess and rank the impact of each varied model parameter a multiple linear regression has been performed. The standardized regression coefficients, the Pearson correlation coefficients as well as the coefficient of multiple determination R2 are discussed. Varied parameters are the collector mirror reflectance, the collector mirror cleanliness factor, the collector glass tube transmittance, the collector receiver tube absorptance, and the collector receiver tube heat loss characteristic. Based on existing and published bibliography, a set of parameter distributions and ranges have been chosen for this work and the simulation results show that the cleanliness factor has the strongest influence on the model output. The cleanliness is followed (in this sequence) by the mirror reflectance, the glass tube transmittance, the receiver tube absorptance and, finally, by the receiver tube heat loss characteristic.

4-E (energy–exergy–environmental–economic) analyses of line-focusing stand-alone concentrating solar power plants

In this study, energy–exergy–environmental–economic (4-E) analyses of stand-alone line-focusing concentrating solar power plants are carried out for different plant capacities ranging from 1 to 50 MWe. Solar power plants based on concentrating power technologies are used to harness the solar radiation effectively. Among the solar power technologies, line-focusing concentrating systems such as linear Fresnel reflector (LFR) and parabolic trough collector (PTC) are simple in design and cost-effective with high dispatchability. The energy and exergy efficiencies of various components of the solar field and power block are determined. The overall energy and exergy efficiencies of 50-MWe LFR power plants are estimated as 12.17 and 17.21% and 23.16 and 32.76%, respectively, for the PTC power plant. The results show that a maximum energy loss occurs in the solar field and power block for LFR and PTC power plants respectively, and a maximum exergy loss occurs in the solar field for both power plants. The analyses of solar power plants have been carried out to estimate the environmental benefits; the results showed that a 1-MWe stand-alone line-focusing concentrating solar power plant can save 1813 tonnes of CO2, 12.52 tonnes of SO2, 6.23 tonnes of NOx and 0.98 tonnes of particulate matter annually compared with that of an Indian subcritical coal power plant. The levelized electricity cost for the LFR- and PTC-based stand-alone solar power plant varies from INR 14.77 to INR 10.19 and INR 14.7 to INR 8.48 for the plant capacities that vary from 1 to 50 MWe.

Technical and Economical Performance of Parabolic Trough Collector Power Plant under Algerian Climate

Parabolic trough solar technology has been proven at nine commercial Solar Electric Generating System (SEGS) power plants that are operating in the California Mojave desert. Simulation using different models when planning this kind of projects and choose the best site for this technology minimizes the risks of these projects. For this purpose, a detailed performance model of the 30 MW SEGS VI parabolic trough power plant was created in the TRNSYS simulation environment using the Solar Thermal Electric Component model library. Both solar and power cycle performance were modeled, but natural gas-fired hybrid operation was not. Good agreement between model predictions and plant measurements was found, with errors usually less than 10%. Also, an economical study has been established to determine the best site, based on the cost of electricity generation. The result shows that Bechar's site is the best site for this technology because of its lowest levelzed electricity cost and its high irradiance level. While the model could be improved, it demonstrates the capability to perform detailed analysis for this technology.

Comparison of Linear Fresnel and Parabolic Trough Collector power plants

Abstract The Linear Fresnel Collector (LFC) technology is currently being commercialised by several companies for the application in solar thermal power plants. This study compares the electricity generation costs for LFC and Parabolic Trough Collector (PTC). PTC is the most commercial CSP technology to date and is therefore regarded as the benchmark. For reasons of comparability, direct steam generation is assumed for both LFC and PTC. For the LFC, cost data comparable to typical CSP plant sizes are hardly available. Therefore, the break even cost – referring to aperture-specific collector investment – is determined, where cost-parity of the electricity generation with a PTC reference plant is reached. This study varies the assumptions on collector performance and operation and maintenance costs to reflect different designs of LFC technologies. The calculations were carried out using cost and hourly simulation performance models. Depending on the assumptions, the costs for a linear Fresnel collector solar field should range between 78 and 216 €/m 2 to reach cost-parity at assumed reference solar field costs of 275 €/m 2 for the PTC. The LFC principle of arranging the mirrors horizontally leads to lower aperture-related optical efficiency which must be compensated by lower cost per m 2 of aperture compared to PTC. The LFC is a collector with significant cost reduction potential, mainly due to cheaper mirrors and structural advantages.The presented cost and performance targets shown in this study must be met by LFC technology developers to reach the PTC benchmark.