Concentrator Photovoltaic Systems Research Articles

Experimental and Economic Analysis of a Concentrating Photovoltaic System Applied to Users of Increasing Size

The costs of concentrating photovoltaic (CPV) and concentrating photovoltaic and thermal (CPV/T) systems are highly reduced in the last years because of their increasing diffusion. The unit power cost also depends on the plant size. Hence, the main aim of this paper is to analyze the feasibility of a CPV/T system adopted for users with increasing sizes located in Salerno (Italy): the house, the hotel, and the food industry. An experimental model was developed for an accurate evaluation of the electrical and thermal powers supplied by the CPV/T system when direct normal irradiation (DNI) and environmental temperature vary. A modular configuration of a line-focus CPV/T system was sized to match the electrical and thermal loads of each user. The current economic results, together with a forecast till the year 2025, were discussed. In 2025, for the same CPV system adopted for the domestic user, the net present value (NPVs) are expected to increase by 6.7% and 13% in pessimistic and optimistic scenarios, respectively, with reductions of its discounted payback period (DPBP) of 16% and 30%. For the same CPV systems adopted for the other two users, the NPVs are expected to increase by about 4.2% and 8.4% in pessimistic and optimistic scenarios, respectively, with decreases of its DPBP of 14% and 27%.

Experimental Comparison between Spherical and Refractive Optics in a Concentrating Photovoltaic System

Since there are not standard configurations of the Concentrating Photovoltaic (CPV) systems, several types of optics are designed and analyzed. In this paper, the optical performances of a spherical mirror and a commonly used Fresnel lens of the same diameter are compared, highlighting their impact on the CPV system energy performance. First, the absolute and percentual variation trends of optical concentration factor and optical efficiency as function of the distance between each optical system and receiver are analyzed. The concentration levels obtained by means of the spherical mirror are much higher than the Fresnel lens, with maximum values of optical efficiency equal to 72.8% and 24.1%, respectively. The analysis of the concentration reduction due to a solar-tracking failure has also allowed the estimation of the acceptance angle, thus observing that the spherical mirror requires a less accurate solar tracker with respect to the Fresnel lens, especially if a secondary optics is adopted. As for the energy comparison, the spherical mirror allows increase of the Triple-Junction (TJ) cell temperature up to about 65 °C higher than the environmental temperature and to reach an electrical power of about 15 W in correspondence of a concentrated solar radiation of 470 kW/m2. Finally, the deviation between the cumulative electric energy produced by the TJ cell in the cases of correct and incorrect solar tracking and for the configurations with and without secondary optics has been also evaluated for both the optics. The equations experimentally obtained in this paper represent a more accurate tool to describe the physical phenomenon in comparison with the equations theoretically obtained for similar CPV systems. The results can be used to design a real CPV system that adopts a Fresnel lens or a spherical mirror. The equations experimentally obtained in this paper represent a more accurate tool to describe the physical phenomenon in comparison with the equations theoretically obtained for similar CPV systems. The results can be used to design a real CPV system that adopts a Fresnel lens or a spherical mirror.

Optical Performance of Single Point-Focus Fresnel Lens Concentrator System for Multiple Multi-Junction Solar Cells—A Numerical Study

This paper investigates the potential of a new integrated solar concentrated photovoltaic (CPV) system that uses a solo point focus Fresnel lens for multiple multi-junction solar cells (MJSCs). The proposed system comprises of an FL concentrator as the primary optical element, a multi-leg homogeniser as the secondary optical element (SOE), a plano-concave lens, and four MJSCs. A three-dimensional model of this system was developed using the ray tracing method to predict the influence of aperture width, height, and position with respect to MJSCs of different reflective and refractive SOE on the overall optical efficiency of the system and the irradiance uniformity achieved on the MJSCs’ surfaces. The results show that the refractive homogeniser using N-BK7 glass can achieve higher optical efficiency (79%) compared to the reflective homogeniser (57.5%). In addition, the peak to average ratio of illumination at MJSCs for the reflective homogeniser ranges from 1.07 to 1.14, while for the refractive homogeniser, it ranges from 1.06 to 1.34, causing minimum effects on the electrical performance of the MJSCs. The novelty of this paper is the development of a high concentration CPV system that integrates multiple MJSCs with a uniform distribution of rays, unlike the conventional CPV systems that utilise a single concentrator onto a single MJSC. The optical efficiency of the CPV system was also examined using both the types of homogeniser (reflective and refractive).

Numerical Analysis on the Performance of High Concentration Photovoltaic Systems Under the Nonuniform Energy Flow Density

Photovoltaic panels can directly convert solar energy into electricity, but temperature will have a certain impact on the efficiency of photovoltaic cells. Especially under the condition of nonuniform energy flow density of high-power concentration, it is of great significance to maintain the temperature uniformity of cells. Therefore, based on the radiation under nonuniform heat flux density, four heat exchangers were proposed: single-channel serpentine flow, multi-channel flat plate, full jet, and single-jet nozzle. Taking into account the uniformity of the cell temperature, the single-jet nozzle and single-channel serpentine flow can better maintain the uniformity of the temperature field compared with other heat exchangers. Especially under high-concentration energy flow density, considering the quality of heat and electricity, the performance of the four-jet nozzles is the best from the perspective of exergy efficiency. Under the condition of four-jet nozzles, the electrical efficiency and thermal efficiency of the cell can be maintained at about 29 and 62.5%, respectively, and the exergy efficiency of the system can reach 31%.

Deciding between concentrated and non-concentrated photovoltaic systems via direct comparison of experiment with opto-thermal computation

Concentrated photovoltaic system provides higher efficiency at the expense of complexity and cost. A direct comparison in performance is made between concentrated and non-concentrated PV units. It is observed that a concentrated system outperforms, not for all, but only for a range of insolation. The range depends majorly on the relative difference between the conversion efficiencies of the PV materials. In-house experiments are performed to evaluate the performance metrics. A GaAs based concentrating PV module is characterized showing nominal efficiency and temperature coefficient to be 24.0% and −0.045%/°C, respectively. A Fresnel lens based tracked concentrator system is designed, fabricated and characterized under different DNI, ambient temperatures and operating cell temperatures (maintained by constant temperature coolant flow). An opto-thermal model, validated against the aforementioned experiments, is employed to make systematic comparison under different insolations. As for example, a CPV system (with CR = 90) with 40%-efficient cells outperforms an NCPV system with 25%-efficient cells only above DNI ∼630 W/m2. Exact value of the critical DNI depends on other operating conditions and effective conversion efficiencies. Here, the presumption of better performance of CPV system under all conditions is proven incorrect and a general methodology is provided for such an important design decision.

Performance evaluation of PV cells in HCPV/T system by a jet impingement/mini-channel cooling scheme

In this investigation, a numerical analysis of a cooling system for a solar panel in a concentration photovoltaic system is conducted. A model of jet impingement /mini-channel heat sink is presented that is supposed to lower the surface temperature of the triple-junction solar cell in a flat-plate concentration solar system. The effect of pin fins angle, for different mass flow rates and concentration ratios on the mentioned system is examined. Temperature distribution, electrical and thermal efficiencies and electrical and thermal exergies are accordingly discussed. Results indicate that the application of a heat sink enhanced with pin fins offers an improvement in heat transfer characteristics with respect to the simple heat sink. Considering the orientation of the heat sink fins, as fins angle increases from 0 to 40 degree, the heat sink temperature reduces from 321.9 K to 321.2 K that results in an electrical efficiency improvement up to 28.95 percent. In addition, for a specified mass flow rate, 0.15 kg/s, the highest electrical and thermal efficiencies reach about 29 and 80 percent respectively for the choicest studied case. The maximum obtained exergy is 2,760.59 W that is related to the case of 40-degree pin fins angle.

Concentrated Solar Power and Photovoltaic Systems: A New Approach to Boost Sustainable Energy for All (Se4all) in Rwanda

The energy sector of today’s Rwanda has made a remarkable growth to some extent in recent years. Although Rwanda has natural energy resources (e.g., hydro, solar, and methane gas, etc.), the country currently has an installed electricity generation capacity of only 226.7 MW from its 45 power plants for a population of about 13 million in 2021. The current national rate of electrification in Rwanda is estimated to 54.5% (i.e.; 39.7% grid-connected and 14.8% off-grid connected systems). This clearly demonstrates that having access to electricity is still a challenge to numerous people not to mention some blackout-related problems. With the ambition of having electricity for all, concentrated solar power (CSP) and photovoltaic (PV) systems are regarded as solutions to the lack of electricity. The production of CSP has still not been seriously considered in Rwanda, even though the technology has attracted significant global attention. Heavy usage of conventional power has led to the depletion of fossil fuels. At the same time, it has highlighted its unfriendly relationship with the environment because of carbon dioxide (CO2) emission, which is a major cause of global warming. Solar power is another source of electricity that has the potential to generate electricity in Rwanda. Firstly, this paper summarizes the present status of CSP and PV systems in Rwanda. Secondly, we conducted a technoeconomic analysis for CSP and PV systems by considering their strengths, weaknesses, opportunities, and threats (SWOT). The input data of the SWOT analysis were obtained from relevant shareholders from the government, power producers, minigrid, off-grid, and private companies in Rwanda. Lastly, the technical and economical feasibilities of CSP and PV microgrid systems in off-grid areas of Rwanda were conducted using the system advisor model (SAM). The simulation results indicate that the off-grid PV microgrid system for the rural community is the most cost-effective because of its low net present cost (NPC). According to the past literature, the outcomes of this paper through the SWOT analyses and the results obtained from the SAM model, both the CSP and PV systems could undoubtedly play a vital role in Rwanda’s rural electrification. In fact, PV systems are strongly recommended in Rwanda because they are rapid and cost-effective ways to provide utility-scale electricity for off-grid modern energy services to the millions of people who lack electricity access.

Investigation of Thermal Stress Arising in a Graphene Neutral Density Filter for Concentrated Photovoltaic System

As an excellent heat spreader candidate, graphene attracts considerable interest concerning its application in concentrated photovoltaic (CPV) systems. The consequences of employing a graphene-coated neutral density (GCND) filter to mitigate concentrated light impact adequately. Hence, the temperature for a concentrated photovoltaic system is reported in this work. A systematic thermal characterisation study was carried out using three different thickness-based GCND filters. Interestingly, using the GCND filter, the focal spot temperature remained considerably lower than that of the incident temperature for a more extended period. The graphene coating orientation further influenced the temperature gradient behaviour of the focal spot and incident temperature. The thermal and electrical results depended on the GC samples’ thickness and emplacement, leading to dramatic differences in their respective photovoltaic performance. As a base substrate of the GCND filter, the low-iron glass suffered extreme thermal stress under concentrated solar irradiance. This thermal stress phenomenon on the GCND filter was further analysed. This study suggests that using GCND leads to lower temperature maintenance of the CPV focal point, which minimises the PV cell thermal stress. However, the GCND filter also experienced considerable thermal stress during the CPV experiment.

Cooling Arrangements for Hybrid Thermal-CPV Receivers with High Output Coolant Temperature for Combined Electricity Generation and Water Desalination

Human civilization uses vast quantities of water and electricity. Natural fresh water is in short supply in many regions, and the shortfall is increasingly filled through energy-intensive desalination. Electricity still largely comes from burning fossil fuels, resulting in CO2 emissions. Concentrator photovoltaics (CPV) can provide not only electricity but also heat from cooling of the CPV cells, providing additional energy for thermally driven processes such as desalination. This paper evaluates a CPV receiver cooling arrangement for linear CPV systems which maximizes electricity production for a given CPV cell area while supplying heat byproduct boosted to a temperature higher than the temperature of the fluid that cools the CPV cells, increasing the range of processes to which the heat can be applied.

Study of luminescent coupling effect in modeling a concentrator photovoltaic system with III-V triple junction solar cell

Abstract A theoretical model is proposed for a concentrator photovoltaic (CPV) system. This model is based on the two-diode equation and considers the luminescent coupling (LC) effect in III-V triple junction solar cell. By using the model, the ‘I-V’ curve of the system is fitted. The fitting result is in good agreement with the experimental data. The system’s open circuit voltage is also predicted in a certain temperature range. Based on the analysis of the simulation results and the two-diode equation, it is concluded that the LC effect should be a non-negligible mechanism for analyzing the operation performance of CPV system.

Performance Analysis and Comparison of a Concentrated Photovoltaic System with Different Phase Change Materials

In this work, temperature regulation and electrical output of a concentrated photovoltaic system coupled with a phase change material (CPVPCM) system is investigated and compared with a single sun crystalline photovoltaic (PV) system. A fully coupled thermal-optical-electrical model has been developed in-house to conduct the simulation studies for actual weather conditions of Doha (Qatar) and selected phase change materials (PCMs). The selected PCMs are lauric acid, RT47, S-series salt, STL47, ClimSelTM C48, RT54, RT60, RT62, and RT64. An optical concentration ratio of 20× is considered on a 15 mm wide crystalline silicon cell. The temperature evolution, thermal energy storage and electrical output of the CPVPCM system are obtained for 48-hour simulations with representative weather conditions for each month of a typical meteorological year (TMY). Results and overall thermal and electrical efficiency are compared for each PCM. In brief, the CPVPCM system with S-series salt performs better than all other PCM with an overall efficiency of 54.4%. Furthermore, this system consistently produces more power than a PV system with an equal footprint (1 m2) for each month of the TMY.

Parametric investigation of a nanofluid-NEPCM based spectral splitting photovoltaic/thermal system

Photovoltaic cells can convert incoming sunlight within their responsive wavelength range into electricity. Unfortunately, the majority of the incident radiation is reflected, absorbed directly as heat, or indirectly converted to heat due to internal losses (i.e., ≥ 52.9%, even world-record efficiency cells). In concentrated photovoltaic systems, this added heat can further degrade the electrical conversion efficiency of the cells if it is not removed, resulting from an elevated operating temperature. Spectral splitters and absorptive filters can remove the unused portion of the solar spectrum before it is converted to heat in the photovoltaic cells and harvest this energy for active use in thermal applications. In this paper, an innovative concentrated photovoltaic/thermal system that utilizes a layered design containing an optical fluid and a phase change material was investigated as a new alternative absorptive filter. Five possible configurations of this filter were compared from energy, exergy, and energy storage perspectives. These layers consist of a phase change material (dotriacontane, a paraffin) layer and fluid channel layers (a glycerol fluid) with suspended Ag and/or Au nanoparticles. The optical properties of the nanofluid and the nano-enhanced phase change material (NEPCM) were modeled using Mie and Rayleigh scattering theories. The comparison showed that the configuration containing the nanofluid channel at the top of the nano-enhanced phase change material performs well in all aspects of energy, exergy, and energy storage. A parametric study was conducted to determine the effects of nanoparticles volume fraction, concentration ratio, mass flow rate, nanofluid thickness and phase change material thickness on PV/T system performance with this filter configuration. It was found that volume fractions lower than 0.3 × 10−5 and 0.2 × 10−5 for Ag and Au, respectively, provided the best system performance for the assumed geometric and operational conditions. At an optimal mass flow of 0.005 kg s−1 for the nanofluid, this design achieved a maximum exergetic efficiency of 24% for a concentration ratio of 30. The results also revealed that the nanofluid-NEPCM filter is not suitable for concentration ratios of less than 10. Overall, this study finds that nanofluid-NEPCM-based spectral splitter, in addition to successfully filtering radiation, can store energy efficiently.

A homogeniser inspired by the crustacean’s eye with uniform irradiance distribution and high optical efficiency characteristics for concentrated photovoltaics system

We devise an implicitly new design for boosting the light uniformity in the concentrated photovoltaics (CPV) system, whereby addressing the overheating issue of the PV cell and enhancing the electrical cell efficiency. Rather than using a well-known system of the Cassegrain concentrator design, consisting of double mirrors + a homogeniser, in this study, we mimic a structure of crustacean’s eyes for a design of homogeniser, consisting of an array of a mirror channel. Such proposed design allows making use of only a primary parabolic mirror + a homogeniser to concentrate and redistribute the sunlight, representing a large departure from virtually all of the previous studies. Specifically, such homogeniser can furcate the light beam into the small channels/trenches, redirect the light ray at the reflective plate and probably mix them to evolve a uniform version of light distribution. In general, the homogeniser can affect the uniformity and optical efficiency, which are good probes to assess the light performance, in a number of ways. We found that light performance depends sizably on the structural parameters such as the size and the number of channels of the homogeniser. The best structure displays a calculated uniformity of ~85% of the flux distribution on solar cell and a calculated optical efficiency of ~90% of the entire CPV system. We also assess the light performance against some scenarios of error in installation and operation processes such as tolerance and misalignment and compare well with the current design. The compelling of this proposed design is highly efficient light performance, compactness and inexpensive, which likely address virtually existing bottlenecks in the CPV system.

Fractional derivative-based performance analysis of hybrid thermoelectric generator-concentrator photovoltaic system

Concentrator photovoltaic systems get the highest conversion efficiencies among all solar applications. However, they need to increase their efficiency even more to compete with traditional photovoltaic systems. The hybridization with thermoelectric generators allows recovering part of the waste heat and converting it to electricity, enhancing the global efficiency. The physical model of hybrid thermoelectric-concentrator photovoltaic module involves five non-linear equations. In this paper, two adapted Newton-Raphson methods using fractional derivatives are developed to solve such non-linear system, one using the conformable derivative operator and the other using the Riemann-Liouville fractional derivative. Both methods are mathematically innovative and are applied within the photovoltaic field for the first time. They can be used in energy prediction or in design optimisation. As an example of application, one month of real atmospheric data from Jaen, Southern Spain, were processed with the help of the developed methods. The performance outputs of the hybrid system were analysed giving interesting findings on their real behaviour, which is largely unknown nowadays. Linear functions dependent on direct normal irradiance can approximate the total generated power with 12.8 W/m2 root mean squared error and, the thermoelectric efficiency with 0.08% error.

Concentrated photovoltaics as light harvesters: Outlook, recent progress, and challenges

Concentrated photovoltaics (CPV) is a dawn technology in the field of photovoltaic that helps in escalating the effective use of solar energy. Nowadays, applications of photovoltaic solar cells are catching attention due to the better utilization of solar energy. A huge amount of solar energy is received by the earth from the sun, but a barrier to the large-scale use of photovoltaic solar cells is their higher initial cost and lower conversion compared to other non-renewable energy systems. Concentrated Photovoltaics (CPV) is one of the vital tools that focus solar radiation on the small area of solar cells using optical devices to maximize solar to thermal conversion. Low cost, high efficiency, and climate-friendly are the main advantages of concentrated photovoltaics. The review study presents the outlook of work conducted worldwide on the different types of concentrated photovoltaics. In addition, the effect of various performance affecting parameters, challenges, and recent progress is also part of the study. Most of the CPV have efficiency up to 15% while some have an efficiency range of 25–28% which is still very low. It was found that the CPV gave maximum efficiency of up to 38.5% at optimal solar radiation. The focus of sunlight on a small area of solar cell increases the temperature of concentrated photovoltaic allegedly pernicious for electrical efficiency and the life of CPV. Factors like direct normal irradiance, high cell temperature, soiling, optical design, reliability, and durability are considered as challenges and a concise summary of various studies on these challenges is presented. In this regard, various cooling techniques have been investigated by different researchers for thermal management of CPV systems which are discussed in detail. As CPV technology is still in the development phase, various new optical designs emphasizing novel designs and materials are also summarized in the current study. Finally, some recommendations are oriented which will be very valuable for those who are working or want to work in the field of photovoltaics.

Nanofluid-PCM heat sink for building integrated concentrated photovoltaic with thermal energy storage and recovery capability

A new configuration of phase change material (PCM) heat sink has been developed to be combined with a building integrated concentrated photovoltaic (BICPV) system. This new proposed system includes PCM encapsulated in aluminum pack and immersed in nanofluid container to improve thermal conductivity. A comprehensive numerical model was validated and simulated to evaluate thermal and electrical performance of the proposed system for both passive and active cooling conditions. Two different configurations of nanofluid-PCM enclosures with single PCM pack or multi-smaller packs were compared with conventional BICPV-PCM system. Melting and solidification of PCM were also studied with solar concentration ratio of 5. In passive cooling, single-pack configuration regulated the silicon temperature of CPV below 78 °C with more uniform temperature distribution. Whereas the multi-packs configuration demonstrated 97% phase transition to liquid PCM which provided the highest stored thermal energy. The performance improvement would be attributed to the enhancement of thermal conductivity and natural convection of nanofluid in PCM container. Furthermore, in active cooling condition, the silicon temperature controlled under 43 °C with uniform distribution. The nanofluid flow could be solidified up to 97% and 90% of initially melted PCM after 60 min for multi-packs and single-pack configurations, respectively.

Concentrator photovoltaic thermal management using a new design of double-layer microchannel heat sink

The concentrator photovoltaic (CPV) systems commonly endure high cell temperatures, which affect their overall performance. Besides, the high cell temperature could lead to physical damages within the whole system due to the induced thermal stresses. Therefore, an efficient cooling is mandatory to achieve a higher net output power from the CPV and safe operation. The current work's main purpose is to investigate the integration of double-layered microchannel heat sink (DL-MCHS) with CPV cell as thermal management device. A three-dimensional (3D) model is presented to investigate the performance of a CPV cooled by the DL-MCHS to figure out the ability to handle the effective heat dissipation under different terrestrial conditions. The parallel flow (PF) and counter flow (CF) cooling orientations were studied. Ethanol coolant is used to cool the CPV under different concentration ratios (CR) of 5, 10, 15, and 20 suns. The results show that the temperatures remarkably decreases with the inlet flowrate is increased. The counter flow operation (CF) achieved the best temperature uniformity index (Tuni) when the coolant mass flowrate (V̇) ranged between 200 and 1200 ml/hr. Especially at CR 5 suns, the temperature uniformity index, Tuni, enhanced to 99.87% at 1200 ml/hr.

Developing automated methods to estimate spectrally resolved direct normal irradiance for solar energy applications

We describe four schemes designed to estimate spectrally resolved direct normal irradiance (DNI) for multi-junction concentrator photovoltaic systems applications. The schemes have increasing levels of complexity in terms of aerosol and circumsolar irradiance (CSI) treatment, ranging from a climatological aerosol classification with no account of CSI, to an approach which includes explicit aerosol typing and type dependent CSI contribution. When tested against ground-based broadband and spectral measurements at five sites spanning a range of aerosol conditions, the most sophisticated scheme yields an average bias of +0.068%, well within photometer calibration uncertainties. The average spread of error is 2.5%. These statistics are markedly better than the climatological approach, which carries an average bias of −1.76% and a spread of 4%. They also improve on an intermediate approach which uses Angström exponents to estimate the spectral variation in aerosol optical depth across the solar energy relevant wavelength domain. This approach results in systematic under and over-estimations of DNI at short and long wavelengths respectively. Incorporating spectral CSI particularly benefits sites which experience a significant amount of coarse aerosol. All approaches we describe use freely available reanalyses and software tools, and can be easily applied to alternative aerosol measurements, including those from satellite.

Experimental characterisation of irradiance and spectral non-uniformity and its impact on multi-junction solar cells: Refractive vs. reflective optics

The impact of non-uniform illumination on triple junction solar cells equipped with either refractive or reflective optics without secondary optical elements is characterised by varying the concentrator-to-receiver distance. Indoor experiments covering both electrical measurements and photographs with a charge-coupled device camera are performed. The non-uniformities are examined by differentiating two spectral bands, those affecting the top and middle subcells. This allows the irradiance and spectral distributions to be analysed. The analysis is complemented with ray tracing simulations. Results show a different behaviour for the refractive and reflective systems. Irradiance non-uniformities in the case of the reflective system around the on-focus position are higher than those measured in the refractive system. However, the spectral non-uniformities that characterise the refractive system constitute only a residual effect in the reflective system. The drop in the solar cell fill factor caused by non-uniformities is mainly driven by the degradation of the slope of the I–V curve near the short-circuit point in the case of the refractive system, while it is mainly driven by the degradation of the slope of the I–V curve near the open-circuit point in the case of the reflective system. Both systems are very sensitive to the concentrator-to-receiver distance, a critical parameter that must be accurately designed in any concentrator system. The findings will allow the trade-off between increasing performance and increasing cost strategies to mitigate the non-uniformities in concentrator photovoltaic systems to be better evaluated.

Exergy analysis of a high concentration photovoltaic and thermal system for comprehensive use of heat and electricity

By analyzing the temperature distribution cloud image of the solar cell, it was found that the temperature distribution was uneven and there was a large temperature gradient, resulting in reduced effective cell size requiring a dual inlet model. At the same time, simulations and experiments were established, and it was found that the simulation results were consistent with the experimental results. This paper offers the first law of thermodynamics efficiency and exergy analysis of a simple optimized model at different inlet flow, concentration ratios and inlet temperatures. The result shows that while the inlet flow is 0.02–0.06 kg/s, the system runs efficiently, which can provide considerable heat output, and has greater protection for the cell. When the concentration ratio increases, thermodynamic efficiency and exergy efficiency will decrease, but the total output exergy is in an increasing trend and the trend will decrease as the concentration ratio increases. As the temperature of cooling water increases, the thermal and overall exergetic efficiencies will also increase, and when the inlet temperature is 60 °C, the electrical efficiency is still greater than 20%. In practical applications, the quality of thermal energy can be improved by increasing cooling water temperature, broadening the field of application.