Parabolic Trough Collector Plant Research Articles

Energy and exergy analysis of a parabolic trough driven an ORC cycle for heat and power supply

Converting solar energy using the Parabolic Trough Collector (PTC) to produce electrical energy and supply industrial heat is one of the most prominent and most popular sustainable and renewable, widely used throughout the worldwide due to its effectiveness and benefit returns. For this reason, this study aims to investigate the effectiveness of these power plants under a specific climatic conditions and analysis the results come out from the simulation using an EES developed model. The analysis investigates the energy and exergy of the PTC plant coupled with Turboden ORC cycle. The presented model allows us to preview the theoretical results and derive the expected results smoothly, with the possibility of development for a better control of the use of renewable energies in the industrial field. The thermal efficiency of the ORC cycle increases as the heat output increases until it reaches an almost constant value above 2801 [kW] in heat output with a output capacity of the ORC cycle about 1 [MW].

Assessment of direct contact membrane distillation system driven by parabolic trough collector plant technology for electricity and freshwater production: Feasibility and benchmark under different Moroccan climates

Morocco has experienced several years of drought, conventional water resources were insufficient to meet the needs of the population, which prompted the kingdom to seek other resources to ensure the supply of drinking water to this population. The most suitable solution was the desalination of seawater. In this context, the design and investigation of concentrated solar power (CSP) plant integrated with a desalination unit in Morocco are presented in this paper. The CSP part consists of a parabolic trough technology with a two-tank storage system, integrated with a power block of 111 MWe gross consisting of a conventional Rankine cycle. As for the desalination part, it consists of a Direct Contact Membrane Distillation System (DCMD) based on heat and mass transfer equations, and is solved numerically by MATLAB environment; the model was validated by means of the experimental data. The results show that the large-scale Parabolic Trough Collector (PTC) plants are more competitive in Dakhla -southern Morocco- where the annual energy generation and the capacity factor were estimated to be 493.8 GWh, and 47.6%, respectively. Whereas, the Levelized Cost of Electricity (LCOE) is 10.63 ȼ/kWh. Furthermore, it has been found that in the DCMD system, an increase in the feed water temperature leads to an increase in permeate flux. Besides, freshwater production is highest in winters for Dakhla and Agadir (Atlantic Ocean) and it is highest in summers for Saidia and Al Hoceima (Mediterranean Sea). The lowest freshwater production cost is 0.84$/m3 in Dakhla, followed by 0.98$/m3 in Saidia, with the highest production cost at 1.20$/m3 in Agadir.

Thermal performance of parabolic trough integrated with thermal energy storage using carbon dioxide, molten salt, and oil

Finding clean and affordable energy sources is the focus of extensive research efforts globally. A primary approach to achieving that is through improving the performance and economic competitiveness of renewable energy systems. Parabolic trough collector (PTC) solar plants are mature renewable solutions to reduce current dependence on fossil fuels. However, in these plants, heat is transferred within the subsystems using a heat transfer fluid (HTF) that is primarily molten salt or synthetic oil. These HTF options play an important role in the thermal and economic performance of the solar power plant. In this paper, supercritical carbon dioxide (s-CO2) is investigated as an economical alternative to the costly molten salt and Therminol-PV1. Therefore, comparative heat transfer, energy, and exergy analyses are conducted for a PTC plant with s-CO2, Therminol-VP1, and molten salt as an HTF. A heat transfer model is developed for the PTC in one- and two-dimensions to accurately evaluate heat losses. In addition, the energy and exergy concepts are used to compare the thermal performance of these HTFs. In contrast to previous studies that were limited to PTC, we considered the integration of thermal energy storage (TES) with both Therminol-PV1 and molten salt as a storage medium for a full-day operating cycle. The PTC performance while using these HTFs under various operating and design conditions is examined, including variation in wind velocity, beam radiation, and pressurized s-CO2 operation. The results show that the considered HTFs are achieving comparable energy and exergy efficiencies within the PTC. Furthermore, the Therminol-PV1 has an advantage of compact storage volume compared with molten salt, about one-third; nevertheless, the latter exhibits higher TES energy and exergy efficiencies. This comparative analysis reveals that the s-CO2 can replace synthetic oil and molten salt in the PTC loop.

Control of Solar Energy Systems

This review deals with the control of parabolic trough collector (PTC) solar power plants. After a brief introduction, we present a description of PTC plants. We then provide a short literature review and describe some of our experiences. We also describe new control trends in PTC plants. Recent research has focused on (a) new control methods using mobile sensors mounted on drones and unmanned ground vehicles as an integral part of the control systems; (b) spatially distributed solar irradiance estimation methods using a variable fleet of sensors mounted on drones and unmanned ground vehicles; (c) strategies to achieve thermal balance in large-scale fields; (d) new model predictive control algorithms using mobile solar sensor estimates and predictions for safer and more efficient plant operation, which allow the effective integration of solar energy and combine coalitional and artificial intelligence techniques; and (e) fault detection and diagnosis methods to ensure safe operation.

Heat transfer improvement using additive manufacturing technologies: a review

To provide a comprehensive review of additive manufacturing use in heat transfer improvement and to carry out the economic feasibility of additive manufacturing compared to conventional manufacturing. Heat transfer improvement is particularly interesting for different industrial sectors due to its economic, practical, and environmental benefits. Three heat transfer improvement techniques are used: active, passive, and compound.According to numerous studies on heat transfer enhancement devices, most configurations with strong heat transfer performance are geometrically complex. Thus, those configurations cannot be easily manufactured using conventional manufacturing. With additive manufacturing, almost any configuration can be manufactured, with the added benefit that the produced parts’ surface characteristics can enhance heat transfer. It can, however, lead to a significant pressure drop increase that will reduce the overall performance. In the given article, a comparison of the capital cost of a 100 MW parabolic trough power plant has been carried out, considering two types of solar receivers; the first is manufactured using conventional methods, and the second uses additive manufacturing. The heat transfer of the new receiver configuration is investigated using computational fluid dynamics through ANYS Fluent.Although the cost of additive manufacturing machines and materials is high compared to conventional manufacturing, the outcome revealed that the gain in efficiency when using additive-manufactured receivers leads to a reduction in the number of receiver tubes and the number of solar collectors needed in the solar field It implies a considerable reduction of parabolic trough collector plant capital cost, which is 20.7%. It can, therefore, be concluded that, even if initial setup expenses are higher, additive manufacturing could be more cost-effective than traditional manufacturing.With the reduction of the parabolic trough collector plant capital cost, the levelized cost of electricity will eventually be reduced, which will play a role in increasing the use of solar thermal energy.No review studies discuss the manufacturing potential and cost-effectiveness potential of additive manufacturing when producing heat transfer improvement equipment, especially when producing long pieces. In addition, the paper uses a novel receiver configuration to investigate the economic aspect.

Optimization and Techno-Economic Appraisal of Parabolic Trough Solar Power Plant under Different Scenarios: A Case Study of Morocco

Morocco is a country with a lack of fossil fuel resources and an increasing demand for energy. This inspired the country to increase the use of renewable energy in the energy mix. The objective of this study was to conduct an optimization and techno-economic appraisal of a concentrated solar power plant (CSP) using different scenarios that took Ouarzazate city in the south of Morocco as a case study. To achieve this, several parameters were assessed, including the impacts of solar collector assemblies (SCAs), receiver types, heat transfer fluids, cooling systems, solar multiples, and thermal storage hours, with regard to the profitability of the CSP plant. Then, performance and sensitivity analyses were conducted to select the best integration scenarios based on different economic indicators, including levelized cost of electricity (LCOE) and net present value (NPV). The findings revealed that the use of the Luz LS-3 as the collector/SCA, Solel UVAC 3 as receiver, and Dowtherm Q as heat transfer fluid exhibited the highest performance in terms of the annual energy production yield and capacity factor, as well as the lowest real and nominal LCOEs with a wet cooled condenser. Furthermore, the LCOE is extremely sensitive to changes in the number of hours of storage and the solar multiple, and the optimal real and nominal LCOEs are determined by a highly specific combination of the solar multiple and the number of hours of storage. As a consequence, the maximum and minimum net electricity outputs for the best configuration of the Parabolic Trough Collector (PTC) plant were 24.6 GWh and 7.4 GWh in May and December, respectively. Likewise, the capacity factor and the gross-to-net conversion factor for the optimized plant were found to be 47.9%, and 93.5%, respectively. Concerning the economic study, the expected energy cost was 0.1303 USD per kWh and the NPV value for Ouarzazate city was positive (more than USD 20 million), which indicates that the studied PTC plant was estimated to be financially and economically feasible. The results of this analysis are highly significant and may persuade decision makers, financiers, and solar energy industry players to increase their investments in the Kingdom of Morocco.

Performance enhancement of parabolic trough collector solar thermal power plants with thermal energy storage capability

This paper proposes a fuzzy non-linear programming based optimisation approach using Genetic algorithm to enhance the performance of commercial parabolic trough collector concentrated solar thermal power plants with thermal energy storage capability. The proposed optimisation approach, unlike conventional methods, considers three plant performance parameters: capacity factor, plant efficiency, and levelized cost of energy for arriving at optimal plant performance. By properly sizing the PTC plant with respect to plant efficiency, thermal energy storage capacity, capacity factor, and levelized cost of electricity, even better performance levels can be achieved. For analysis purpose and to validate the efficiency of the proposed approach, three representative locations in Saudi Arabia: Yanbu, Abha, and Dawadmi were considered—wherein the design of a 100 MW commercial parabolic trough collector solar thermal power plant is optimised. The results showed that the proposed optimization approach when applied to commercial parabolic trough collector plants with thermal energy storage capability can achieve superior plant efficiency of the order of 16.53% and 17.42% and with a capacity factor greater than 60%. The findings of the study has been validated with the help of operational parameters of the commercially operated Andasol-1, La Florida, and Aste 1A parabolic trough collector concentrated solar power plants. The results confirm the efficacy of the proposed optimization approach as it achieved superior plant efficiency. This will put decision makers in better position while choosing the ideal solar thermal technology for a particular location. This research work will help augment the competitiveness and efficacy of parabolic trough collector concentrated solar power technology and prompt policymakers to increase their share in the global renewable energy mix.

Dynamic optimization with flexible heat integration of a solar parabolic trough collector plant with thermal energy storage used for industrial process heat

There is an increasing need to reduce fossil fuel consumption used for industrial process heat to slow the effects of climate change. Using solar thermal heat is a viable way to replace fossil fuel use, but solar industrial process heat plants have limited implementation due to large upfront costs and inefficiencies from the inherent variability from solar energy. Having more flexible and optimized control over these plants can enable them to be more efficient. In this work, a solar industrial process heat plant with thermal energy storage that can flexibly collect and deliver heat to two industrial processes (flexible heat integration) is dynamically modeled with control setpoints found by a dynamic optimization method. The optimized case can increase the solar efficiency of the plant by 7.5% on average relative to a base case. Results show that it is best to collect heat at lower temperatures for all but ideal solar conditions, only medium to high quality heat should be stored in large quantities, and exchanging heat with a lower temperature heat sink is generally more efficient. The optimized case is able to reduce the levelized cost of heat of the plant to $31.83/MWhth compared to a base case value of $34.10/MWhth. The optimized case can reduce emissions by 22.2% compared to a plant which uses only natural gas. This work shows that dynamic optimization with flexible heat integration can be a cost-effective way to increase efficiency so that more of these types of plants can be implemented.

Simulating a solar parabolic trough collector plant used for industrial process heat using an optimized operating scheme that utilizes flexible heat integration

This study focuses on the modeling and simulation of a novel design and operation of a solar industrial process heat (SIPH) plant that uses a parabolic trough collector system for generating process heat. The SIPH plant incorporates flexible heat integration (FHI) by having two options for heat sinks as well as a flexible collection temperature for the heat transfer fluid. Leveraging the degrees of freedom created by FHI allows an optimized operating scheme to be created which maximizes the solar heat delivered to the industrial processes. Yearly results for a 27 MW-t plant located in Salt Lake City, UT are simulated for a base case and a case utilizing optimized FHI. For the main process temperature case presented, FHI increases the total solar share by 13.0% and reduces the levelized cost of heat of the SIPH plant by 10.4% relative to the base case. Three case study days are presented which highlight how FHI maximizes solar share, specifically during mornings, afternoons, and days with intermittent solar conditions. An environmental analysis is also performed showing that the SIPH plant can reduce harmful emissions by 15.4% for the base case and 17.4% for the FHI case compared to a plant that only utilizes a natural gas furnace for process heat. Overall, the work thoroughly explores an effective operating scheme for a SIPH plant, helping to make it more economical and environmentally beneficial.

Assessment of Direct Contact Membrane Distillation System Driven by Parabolic Trough Collector Plant Technology for Electricity and Freshwater Production: Feasibility and Benchmark Under Different Moroccan Climates

Assessment of Direct Contact Membrane Distillation System Driven by Parabolic Trough Collector Plant Technology for Electricity and Freshwater Production: Feasibility and Benchmark Under Different Moroccan Climates

Hydrogen production through parabolic trough power plant based on the Organic Rankine Cycle implemented in the Algerian Sahara

This paper investigates overall performance of a small-scale electrolytic hydrogen production, using an Organic Rankine Cycle (ORC) driven by a parabolic trough collector (PTC) plant, under the Algerian Sahara climate. The evaluations of PTC plant and the thermodynamic analysis of the ORC are performed by SAM and EES software, respectively. These results are then used for hydrogen production calculations. Among three southern cities investigated, Ghardaïa is most favorable site to implement the proposed system. For the ORC plant, eight alternative working fluids (butane, n-pentane, isopentane, benzene, toluene, R245fa, R123 and water), are considered for comparison. As results, the highest output power and plant efficiency are achieved with benzene during May to August with maximum power of 8.74 kW and cycle efficiency of 21.65% during July. The highest hydrogen production rate is achieved in July with 847 Nm3 using the high temperature water vapor electrolyzer and benzene as working fluid.

Estimating capital cost of parabolic trough collector based concentrating solar power plants for financial appraisal: Approaches and a case study for India

An attempt has been made to estimate the unit capital cost of parabolic trough collector (PTC) based concentrating solar power (CSP) plants in India to facilitate their financial appraisal. While reviewing approaches mentioned in the literature, a significant variation is observed in unit capital cost estimates for a 50 MW wet cooled without storage PTC based plant (US $1700 to US $2662 per kW). To internalize the effect of alternate condenser cooling options and thermal energy storage on the unit capital cost, a new approach that is based on inventory of material used and associated costs have been suggested. With the use of this approach, the unit capital cost of a 50 MW wet cooled PTC plant is estimated at US $1734 per kW. Similarly, for the same nominal capacity plant with dry cooling, the unit capital cost is estimated at US $1994 per kW. Moreover, the effects of increased nominal capacity and hours of thermal energy storage on the unit capital cost have also been investigated.

Thermo-economic analysis of photovoltaic, central tower receiver and parabolic trough power plants for Herat city in Afghanistan

In Afghanistan, more than 60% of the population does not have access to a reliable source of electrical energy. A thermo-economic analysis is conducted to compare the performance of a Photovoltaic (PV), Central Tower Receiver (CTR) plant and a Parabolic Trough Collector (PTC) plant with and without storage for the city of Herat, in Afghanistan. The nominal capacity of both plants is 110 MWe. The PTC plant with energy storage has the highest efficiency of about 43% that is approximately 50% more than the PV plant, however, the PV plant has more uniform power production profile. The output power of PTC with energy storage is 25% more than output power of PTC without energy storage and output power of CTR plant is half of PTC plant with energy storage. The Levelized Cost of Electricity (LCOE) is 0.146 $/kWh for CTR plant, 0.063 $/kWh for PV plant, 0.1076 $/kWh for PTC plant with energy storage, 0.104 $/kWh for PTC plant without storage and 0.12 $/kWh for PTC plat without storage and without backup fossil fuel systems. Increase of incentive by 10% leads to decrease of LCOE by about 20% for PTC and 13% for PV and 12% for CTR power plants.

Comparison of carbon capture system and concentrated solar power in natural gas combined cycle: Exergetic and exergoenvironmental analyses

Two emissions mitigation systems, as CO2 capture and storage (CCS) and concentrated solar power (CSP) have been investigated to a power plant based on exergetic and exergoenvironmental analyses. A base plant of natural gas combined cycle for power production is taken as case study. The CSP technology used is parabolic trough collector (PTC) with two storage tanks. The environmental impact indicator used is the eco-indicator 99. The outcomes indicate that the natural gas heater exchanger should have its exergy destruction reduced to improve the performance of all system. The CCS plant reduced the net power and the PTC plant increased slightly the net power in relation to the base plant. The specific environmental impact of CCS plant was increased and of PTC plant was slightly decreased. The environmental impact of fuel production is the main environmental burden in the environmental performance. Therefore, the PTC system is the best case of mitigation system. Discussions about further improvements have been proposed.

Simulation and experimental validation of a parabolic trough plant for solar thermal applications under the semi-arid climate conditions

In this paper, yield analysis of a 186 kWth parabolic trough collector (PTC) system for medium-temperature heat process applications, is conducted under a semi-arid climate (Benguerir, Morocco). For this purpose, a PTC model is simulated and validated using experimental data from a PTC test loop, installed at the Green Energy Park research facility. Following, the studied system is simulated using high-quality meteorological data measured at ground level for three years. The impact of soiling on the system’s heat production is studied, considering it as a time-dependent parameter. Finally, an economic analysis is conducted considering as indicators the Levelized cost of heat (LCOH) and the payback time.According to the results, the used model for PTC simulation is accurate, where the daily average deviation is around 4.8% under clear sky conditions. Furthermore, and based on the simulation results, integration of PTC in the Moroccan industrial processes can be very beneficial, where the proposed 186 kWth PTC plant can produce about 388 Tons of saturated steam at 5 bars, annually. Nevertheless, soiling is a limiting efficiency factor especially during the dry period of the year, where the solar field daily average thermal losses can reach 354 kWthh, which is equivalent to a drop of 27% in the production. Economic evaluation results showed that for a low-cost PTC (<250 €/m2), an LCOH and payback period of respectively 0.03 €/kWthh and six years can be obtained, which makes the investment financially reliable.

Feasibility Study of Freeze Recovery Options in Parabolic Trough Collector Plants Working with Molten Salt as Heat Transfer Fluid

Parabolic trough collector (PTC) technology is currently the most mature solar technology, which has led to the accumulation of relevant operational experience. The overall performance and efficiency of these plants depends on several components, and the heat transfer fluid (HTF) is one of the most important ones. Using molten salts as HTFs has the advantage of being able to work at higher temperatures, but it also has the disadvantage of the potential freezing of the HTF in pipes and components. This paper models and evaluates two methods of freeze recovery, which is needed for this HTF system design: Heat tracing in pipes and components, and impedance melting in the solar field. The model is used to compare the parasitic consumption in three molten salts mixtures, namely Solar Salt, HiTec, and HiTec XL, and the feasibility of this system in a freezing event. After the investigation of each of these subsystems, it was concluded that freeze recovery for a molten salt plant is possible.

Current energy mix and techno-economic analysis of concentrating solar power (CSP) technologies in Malaysia

This study performs a techno-economic analysis of concentrating solar power (CSP) technologies for Malaysia. The solar resource assessment was done by analyzing various rural and regional locations using NASA Surface Meteorology and Solar Energy database. Three different technologies, parabolic trough collector (PTC), solar power tower (SPT) and solar parabolic dish (SPD) were assessed under different economic criterions. Results based on the analysis show that PTC and SPT type plants are particularly suitable for locations at East and Peninsular Malaysia. However, considering simple payback, the net present value (NPV) and internal rate of return (IRR), it is found that PTC type CSP plant will be the most eligible for CSP plant development. Sensitivity analysis is performed to investigate the effect of the levelized cost of electricity (LCOE) on the various project discount rate. Regional renewable energy policy development and regulatory reform in feed-in-tariff (FiT), hybrid technology (PTC with biogas, solar PV and biomass) implementation, project financing under clean development mechanism (CDM) and lesson learned from international experience in local PTC equipment manufacturing are some of the crucial future policy outlooks that need to be applied for CSP technology implementation, as well as long-term sustainable renewable energy system development in the country.

Solar multiple optimization of a DSG linear Fresnel power plant

Linear Fresnel power plants are currently one of the most promising concentrating solar power plants. However there are only a few commercial projects. These power plants have a lower efficiency than parabolic trough collector plants and are still expensive. To increase the efficiency of these plants, the utilization of water/steam in the receivers (direct steam generation, DSG) and thermal storage (TES) have been considered.As case study, a 50MWe solar-only linear Fresnel power plant located in Seville, Spain is considered. The effects of the solar field size and the thermal storage size on the annual production of the plant are analyzed: Nine different solar field sizes and up to eight thermal storage sizes have been compared.An economic optimization is presented in order to determine which plant has lowest Levelized Cost of Electricity (LCOE). It has been found that for the power plants with no-storage the optimum solar multiple (SM) is 1.7, whereas for the cases with thermal storage, the optimum configuration is a larger solar field (SM = 2), with a thermal storage of 2 h.

Wind barriers optimization for minimizing collector mirror soiling in a parabolic trough collector plant

Wind barriers, according to their sizes and shapes, can effectively control, shift and even modify the airflow field in their downstream. These structures can accelerate the wind flow over the mirror field and move the airborne particles away from the mirrors. For example, in concentrated solar power plants it is highly desirable to engineer the system in a way that fewer particles are deposited within the solar field, in particular, onto mirror surfaces. Therefore, design optimization of dust barriers could significantly impact the mirror soiling and favourably reduce the cleaning water consumption of a solar power plant. This study focuses on the optimization of a solid wind barrier around a parabolic trough collector plant for their protection against dust soiling. The presented simulation results show that an optimum solid wind barrier is able to direct large amount of particles (in this study, more than 86%) to pass over the solar field with very small fraction (around 0.8%) being deposited on the mirrors. In addition, it was found that the barrier wall is more effective in deflecting the larger particles from the solar field.

Thermal plant based on parabolic trough collectors for industrial process heat generation in Morocco

In the last decades, solar thermal power plants based on parabolic trough concentrators have been widely deployed in the industry sectors. Indeed, there are various applications for thermal plants in industry, such as desalination, refrigeration and air heating. In this work, a dynamic simulation of a small sized parabolic trough collector plant is conducted, using TRNSYS software, for the purpose of generating heated air for an industrial factory. In order to analyze the configuration proposed for this plant, the selected case study is a food industry which requires heated air at 150 °C (medium range temperature) during a daily operation time 8:30 to 00:00 h, throughout the year. The simulation is conducted under Moroccan meteorological conditions in order to encourage the use of this technology in this country. The design and control of the plant are presented and the simulation results are analyzed on different time bases illustrating energetic and exergetic performance data. The environmental impact has been analyzed by focusing on the amount of CO2 emissions resulting of the natural gas combustion at the auxiliary heater subsystem. Calculations determine that up of 57% of CO2 emissions can be avoided annually by the implementation of the solar plant.