Multi-effect Desalination System Research Articles

Development and assessment of an integrated multigenerational energy system with cobalt-chlorine hydrogen generation cycle

This study aims to develop and assess a new multigeneration system where nuclear heat is utilized as the energy source. The multigeneration system is further designed to generate power, cooling, freshwater and hydrogen. In the present multigeneration system, five main subsystems, including high-temperature gas-cooled pebble bed nuclear reactors, a Rankine cycle, a cobalt-chlorine thermochemical cycle, a multi-effect desalination system and an ammonia-water absorption refrigeration system are integrated for synchronized operation. The analyses of the present system are carried out with the approaches of energy and exergy. This integrated system uses a total of 1000 MW thermal energy that is obtained from four units of high-temperature gas-cooled pebble bed nuclear reactor. Using all the thermal energy that comes from the nuclear reactors, a total of 346.99 MW of electricity, a total of 1.59 MW of cooling, a total of 384.67 kg/s of freshwater, and a total of 0.25 kg/s of hydrogen are produced. The energetic and exergetic performance coefficients of the ammonia-water absorption refrigeration system are 0.74 and 0.83, respectively. While the energy efficiency for the overall system is calculated as 37.83%, the exergy efficiency is found to be higher as 46.32% with the multiple useful outputs which help exergetically improve the overall system.

Assessment of a solar-powered trigeneration plant integrated with thermal energy storage using phase change materials

This study presents a comprehensive thermodynamic assessment of a trigeneration plant producing electricity, fresh water through multi-effect desalination (MED), and cooling through an absorption refrigeration cycle. The MED and absorption refrigeration systems utilize the rejected heat from the power cycle, driven by concentrated solar power (CSP). Situated in Qatar, the present system leverages the abundant solar irradiance to optimize the efficiency of electricity generation, water desalination, and cooling. The design features parabolic trough collectors with synthetic oil as the heat transfer fluid, direct thermal storage, and a Rankine steam turbine cycle with three turbine stages. The system also incorporates phase change materials (PCMs) based thermal energy storage (TES) to improve the system performance and offset the mismatch between demand and supply. The present system evaluation is based on energy and exergy analyses, while the Aspen Plus is used to simulate the power production and desalination operations, providing detailed insights into its efficiency and potential for large-scale implementation. The proposed system operates with an energy efficiency of 56.72 % and an exergy efficiency of 31.24 %, respectively.

Utilizing waste heat in wastewater treatment plants for water desalination: Modeling and Multi-Objective optimization of a Multi-Effect desalination system using Decision Tree Regression and Pelican optimization algorithm

This paper examines the feasibility of using waste heat from wastewater treatment plants (WWTPs) for water desalination. A model was developed to utilize waste heat from the gensets at As Samra WWTP in Jordan, using real data and TRNSYS® software to calculate available waste heat. The desalination process was then modeled with ASPEN PLUS® software, focusing on multi-effect desalination (MED). Both series and parallel configurations for the MED system were compared. The study investigated the effects of system feeding flow rate, feeding pressure, and heat input on productivity, performance ratio, and recovery ratio. The study also introduces a novel optimization technique combining machine learning and modern optimization algorithms to maximize system productivity and performance. Initially, a decision tree regression (DTR) model is developed to establish relationships between key independent variables (flow rate, feed pressure, and heat input) and dependent variables (productivity, performance ratio, and recovery ratio). The Pelican Optimization Algorithm (POA) is then used to identify the optimal values of the independent variables for maximum productivity and performance. The results show that using a series configuration yields a system productivity of 3984.2 kg/hr, a performance ratio of 3.78, and a recovery ratio of 0.991 at a feed flow rate of 4000 kg/hr, feed pressure of 3 bars, and heat input of 719 kW. Optimal productivity (4421 kg/hr), performance ratio (3.81), and recovery ratio (0.851) are achieved at a feed flow rate of 5166 kg/hr, feed pressure of 3.2 bars, and heat input of 794 kW. The techno-economic assessment indicates a levelized cost of water of 1.63 USD/m3 for parallel configurations and 1.65 USD/m3 for series configurations, with a payback period of less than two years.

Development and assessment of a floating photovoltaic-based hydrogen production system integrated with storage options

The integrated system approach utilized in the current study represents an innovative approach to harnessing solar energy through a floating photovoltaic-based integrated plant featuring a diverse array of energy storage options. As part of this research, a solar energy system integrating both floating and concentrating solar technologies was designed at the specified site. Despite the constraints presented by the cold temperature at the chosen location, particularly during the winter months when solar irradiation is restricted, strategies are employed, such as exploiting the high albedo effect caused by the freezing of the water body, optimizing the application of solar radiation, and assuring the system's resilience and energy efficiency. Floating photovoltaic and concentrated solar panels are integral components of this advanced system, which is supplemented by underground hot and cold storage units, underground hydro-pumped storage, a multi-effect desalination system with freshwater storage, a lithium bromide absorption cooling system, and an alkaline electrolysis system for hydrogen and oxygen storage. This comprehensive energy strategy includes diverse storage and production technologies. The thermodynamic analyses and assessments employing the Engineering Equation Solver and the System Advisor Model provide some quantitative performance evaluations. The study considers time-dependent operational characteristics, illustrates the water withdrawal rates, energy and exergy efficiencies of the heating space temperature, inverter efficiency, GHI irradiance, mass, and volume values of the heat transfer fluid in both hot and cold tanks within thermal energy storage, annual cooling generation over a year, power production, hydropower storage, and hydrogen storage over a year. The system's concentrated solar panels are projected to generate an annual AC output of 180.79 GWh, with a yearly water usage of 14,055 m3, while floating panels are predicted to provide 7000 kWh with a 0.85 performance ratio. The overall energy efficiency of the current system is determined to be 51.76 %, and the exergy efficiency is found to be 55.41 %, respectively. Optimizing energy efficiency, utilizing diverse storage solutions, and utilizing aquatic environments minimizes environmental impact, and time-dependent analysis enhances perceptions of performance throughout different times and circumstances.

Energy and exergoeconomic analyses of parallel cross feed multi effect desalination system driven by twin-screw compressor with water injection

This work proposes the design of a parallel cross-feed multi-effect desalination system with a twin-screw compressor, incorporating water injection to enhance system performance. The improvement is achieved by injecting water during the compression process to increase the isentropic efficiency of compression. The mathematical model is solved using Engineering Equation Solver software, and the resulting mass and energy balance equations are validated against literature data. The system is analyzed and evaluated from energy, exergy, and exergy-economic perspectives, and compared with the performance of the conventional configuration in terms of specific power consumption, exergy efficiency, and cost of produced water. The impact of various operating conditions, such as the number of effects, steam temperature, compressor efficiency, and injection pressure, on specific power consumption, exergy efficiency, exergy destruction, and final product cost, is examined in this study. Additionally, factors like interest rate, plant life expectancy, and electricity cost are investigated for their effect on the final product cost. The study demonstrates that replacing the normal compressor with a twin-screw compressor result in more than a 15 % reduction in specific power consumption, approximately 4 % less exergy destruction (indicating higher exergy efficiency), and a 14 % lower unit cost of freshwater.

Operating Energy Needed for Desalination Systems in Cogeneration Plants

This study investigated the energy requirement for running desalination units coupled to cogeneration plants. Various cogeneration systems were explored using power- and heat-allocated approaches. The specific work and heat necessary for operating different desalination systems were determined. The investigation revealed that the specific work and heat remain consistent regardless of the desalination daily capacity. It was observed that the energy demand for operating a desalination system mainly relies on power plant efficiency. The investigation revealed that the energy demand for a plain multi-effect desalination system was lower than that for multi-effect desalination with thermal vapor compression. Additionally, the energy requirement for a multi-effect desalination system with preheaters was lower than that for plain multi-effect desalination. Comparisons also indicated that the energy demand of multi-stage flash exceeds that of different multi-effect desalination systems. Based on the primary thermal energy input, a universal performance ratio was used to evaluate the desalination unit performance. Furthermore, a new correlation was proposed to predict the universal performance ratio.

Machine learning assisted improved desalination pilot system design and experimentation for the circular economy

Desalination is among the most feasible solutions to supply sustainable and clean drinking water in water scarcity areas. In this regard, Multi-Effect Desalination (MED) systems are particularly preferred for harsh feeds (high temperature and salinity) because of their robust mode of operation for water production. However, maintaining the efficient operation of the MED systems is challenging because of the large system design and variables' interdependencies that are sensitive to the distillate production. Therefore, this research leverages the power of machine learning and optimization to estimate the optimal operating conditions for the maximum distillate production from the MED system. In the first step, detailed experimentation is conducted for distillate production against hot water temperature (HWT) varying from 38 to 70 °C, and feed water temperature (FWT) is changed from 34 to 42 °C. Whereas, the feed flow rate (FFR) is investigated to be varied nearly from 3.6 to 8.7 LPM in the three stages, i.e., FFR-S1, FFR-S2 and FFR-S3. The compiled dataset is used to make the process models of the MED system by three ML-based algorithms, i.e., Artificial Neural Network (ANN), Support Vector Machine (SVM), and Gaussian Process Regression (GPR) under rigorous hyperparameters optimization. GPR exhibited superior predictive performance than those of ANN and SVM on R2 value of 0.99 and RMSE of 0.026 LPM. Monte Carlo technique-based variable significance analysis revealed that the HWT has the highest effect on distillate production with a percentage significance of 95.6 %. Then Genetic Algorithm is used to maximize the distillate production with the GPR model embedded in the optimization problem. The GPR-GA driven maximum distillate production is estimated on HWT = 70 ± 0.5 °C, FWT = 40 ± 2.5 °C, FFR-S1 = 6 ± 2.6 LPM, FFR-S2 = 7 ± 1 LPM and FFR-S3 = 7 ± 1. The ML-GA-based system analysis and optimization of the MED system can boost the distillate production that promotes operation excellence and circular economy from the desalination sector.

Evaluation of mechanical vapor recompression and easy multi-effect desalination systems in different climate conditions-sensitivity and 7E analysis

Evaporative desalination systems, such as Multi-Effect Desalination (MED) and Mechanical Vapor Recompression (MVR), play important roles in addressing this challenge. Although large-scale desalination systems possess limitations in catering to the water demands of remote regions and islands and entail the cost of water transportation to residential areas, it is imperative to concentrate on studying the feasibility of employing centralized evaporative water production systems. Firstly, in this study, the initial focus is on conducting energy and exergy analyses of MVR and Easy MED systems, with a goal of enhancing knowledge about the energy consumption, exergy destruction and exergetic efficiency of these systems. Secondly, an economic analysis is undertaken to assess the feasibility of deploying these systems in various global regions. The analysis takes into account different geographical and techno-economic conditions, such as sea water temperature, interest rates, and electricity costs. This investigation also aims to explore variations in Annual Operative Cost (AOC), Total Annual Cost (TAC) and the cost of fresh water across these diverse regions. Thirdly, a sensitivity analysis is performed for the economic assessment of MVR and Easy MED systems. Lastly, exergoeconomic, environmental, enviroeconomic and exergoenvironmental analyses are conducted for both of these systems. The results show that the exergy efficiency of the Easy MED system surpasses that of the MVR, whereby the exergy destruction for Easy MED and MVR are recorded to be 5460 W and 6360 W respectiveyl. In addition to this, the MVR system demonstrated a higher TAC across all cities. The freshwater production cost of the Easy MED system was less expensive than of the MVR system. Perth was the most cost-effective city, with freshwater costs of 6.8 €/m3 and 11.91 €/m3 for MVR and Easy MED systems, respectively. Further to this, sensitivity analysis revealed that both systems are sensitive to fluctuations in electricity costs and seawater temperatures. The MVR system incurred higher fuel, product, and exergy destruction costs. However, the MVR system also exhibited greater environmental friendliness due to its lower emission of pollution gases.

Solar driven desalination system for power and desalination water production by concentrated PVT and MED system

Abstract In this paper, a thermodynamic study of the combination of Concentrated Photovoltaic Thermal (CPVT) and Multi Effect Desalination (MED) system was conducted. CPVT produces electricity, and the heat produced in CPVT is used for the MED system. Engineering Equation Software (EES) was utilized to simulate this system. The effect of CPVT parameters (area, concentration ratio, and average solar radiation) and MED parameters (effect number and temperature of heating steam) were investigated on the produced heat, produced power, exergy destruction, total mass flow rate (FR) of desalinated water, total FR of feed water, heating steam FR and total brine FR. The range of changes for CPVT surface, concentration ratio, and average solar radiation was considered from 2000 m2 to 20000 m2, from 5 to 15 and from 400 W/m2 to 1100 W/m2, respectively. Based on obtained results, as the surface area of the solar panel, the ratio of concentration, and average solar radiation increase, the heat produced increases. Transferring this heat to the MED unit increases the total FR of desalinated water. But it has no significant effect on the Gain ratio (GOR). As the surface area of the solar panel increases from 10000 m2 to 12000 m2, the average radiation intensity increases from 800 W/m2 to 1000 W/m2, and the concentration ratio increases from 10 to 12 in effect the number of 4 and steam temperature of 70 °C, the total mass FR of desalinated water increases by 29 %, 23 %, and 20 %, respectively.

Energy and exergo-economic analysis of a parallel feed multi-effect system integrated with humidification–dehumidification system for brine recovery

Desalination technologies reject large amounts of brine with significant value back to sea. The concept of hybridization of different desalination technologies has proven that it can be effective in terms of reducing rejected brine and increasing the freshwater production rate as well as reducing the freshwater cost. In this work, brine recovery to improve water production through a simple modified configuration of integrating a multi-effect desalination (MED) system with humidification–dehumidification system (HDH). The rejected brine of the MED system is used as the feed for the HDH system without the need for preheating the rejected brine since it leaves the MED at a suitable temperature for HDH application. The study focuses on investigating the effect of different operating conditions on the increase in system freshwater production rate and recovery ratio as well as the exergetic efficiency. Parameters investigated include steam temperature, feed salinity, number of brine streams, cooling water flow rate, and ambient temperature. An exergo-economic analysis has also been conducted using the cost flow method to evaluate the freshwater production cost for the modified system. Results indicate that the integration of HDH can increase the water production rate by a maximum of 7.82% and produce fresh water at 2.08 $/m3 compared to 2.094 $/m3 when using the standalone system under the same conditions.

Techno-economic optimization and Nox emission reduction through steam injection in gas turbine combustion chamber for waste heat recovery and water production

Considering the persistent human need for electricity and fresh water, cogeneration systems based on the production of these two products have attracted the attention of researchers. This study investigates a cogeneration system of electricity and fresh water based on gas turbine (GT) as the prime mover. The wasted energy of the GT exhaust gases is absorbed by a heat recovery steam generator (HRSG) and supplies the superheat steam required by the steam turbine (ST). In order to produce fresh water, a multi-effect desalination (MED) system is applied. The motive steam required is provided by extracting steam from the ST. In order to reduce the environmental pollution of this cogeneration system, the steam injection method is proposed in the GT's combustion chamber (CC). This system is optimized by a multi-objective optimization tool based on the Genetic Algorithm (GA). The design variables include pressure ratio of compressor (CPR), inlet temperature of gas turbine (TIT), steam injection mass flow rate in the CC, HRSG operating pressure, HRSG evaporator pinch point temperature difference (PPTD), steam pressure of the MED ejector, ejector motive steam flow rate, number of MED effects, and return effect. The goals are to minimize the total cost rate (TCR), which includes the cost of initial investment and maintenance of the system, the cost of consumed fuel, and the cost of disposing of CO and NO pollutants, as well as maximizing the exergy efficiency. In the end, it is observed that the steam injection in the CC leads to the reduction of the mentioned pollutant index, and it is proposed as a suitable solution to reduce the pollution of the proposed cogeneration system.

Assessment of a new binary geothermal based methanol synthesis plant with power, hydrogen and freshwater

The development of an integrated binary geothermal energy production system for the synthesis of green methanol with electricity and freshwater is achieved in this study along with its thermodynamic analysis and assessment through the applications of energy and exergy methodologies. Further to being among the most promising solutions for the future, clean energy sources provide a wide range of energy carriers that may be utilized by communities as well as individuals. Among these energy carriers, hydrogen has attracted considerable attention as a realistic long-term carbon-free energy route. Moreover, methanol and ethanol are proposed as alternative energy carriers synthesized by clean hydrogen. In this regard, the developed system includes a double flash binary geothermal system, an organic Rankine cycle, a multi-effect desalination system, an alkaline electrolyzer, and a methanol synthesis system. In this system, an alkaline electrolyzer is utilized to perform hydrogen production, and then the produced hydrogen is employed for green (clean) methanol production. The performance-related parameters for the overall system and its subsystems are all thermodynamically evaluated with the Engineering Equation Solver software. The developed system utilizes geothermal energy as a renewable energy source and results confirm that the developed system produces a capacity of 0.019 kg/s of green methanol. The parametric studies are further performed to demonstrate the effects of various first flashing pressures on the qualities of steam, mass flow rates of high pressure turbine, and energy and exergy efficiencies. Moreover, the effects of geothermal well temperature on energy and exergy efficiencies are considered. The effects of electrolyzer power usage and general efficiency on the methanol production rate are alsoexamined. The overall energy and exergy efficiencies of the system are determined as 36.96% and 39.31%, respectively.

Experimental studies on solar multi - effect sea water desalination system

A multi - effect desalination (MED) system with a capacity of 10 m3 has been designed, fabricated, erected and experimented to convert sea water into potable water using solar energy. Steam is flashed initially in the flash chamber of the desalination plant, using hot water from a solar flat plate collector field and is fed to the first stage of the multi-effect evaporator. The average hot water temperature realised from the collector field is 75°C. In the multi-stage evaporator, sea water is sprayed parallelly to vacuum pressure to produce water vapour and simultaneously condense the water vapour flashing through the tube from the flash chamber / previous effects. The brine and condensate is carried to the last stage of the multi-effect desalination (MED) system by utilizing monometric head. It is observed that during the experimentation, the maximum temperature difference between inlet and outlet of the condenser cooling water is 13°C. The ejector is used to maintain the vacuum pressure during the operation of MED system including flash chamber. Experimental studies on the MED system is carried out to understand the performance as well as thermal behaviour of the system using exclusively solar energy.

Conventional and advanced exergy and exergoeconomic analysis of a novel multi-fueled cogeneration system with desalination

This work presents the economic, advanced thermodynamic, and exergoeconomic studies of a system for producing power and freshwater. The proposed system comprises a multi-effect desalination system, an organic Rankine cycle, a centrifuge, and process heaters by utilizing a mix of bagasse and municipal solid waste as primary fuels. The amounts of avoidable, unavoidable, endogenous, and exogenous shares of exergy destruction for the cycle’s components have been calculated by an advanced exergy method. For the integrated cycle, the electricity generation and freshwater productions are 36.6 MW and 7000 m3 per day, respectively. The costs of electricity production and water desalination are 2.6 US$/GJ and 4.6 US$/m3. To present an improved understanding of the system operation, an advanced exergy study is conducted on each involved component of the system at their operating conditions to identify the share of the avoidable irreversibilities. For the integrated system, 85% of the total exergy destruction is calculated to be unavoidable and just 15% of the estimated amount is avoidable. In this case, the opportunity to enhance the system’s operation is roughly limited. Additionally, 76% of the exergy destruction is endogenous, and the remaining belongs to exogenous exergy destruction.

Multi-objective optimization with multiple Pareto frontiers applied to a MED desalination system

This article presents the simulation results of a Multi Effect Desalination system coupled to a Mechanical Vapor Compression system. The system is optimized with the Non-dominated Sorting Genetic Algorithm II genetic algorithm by obtaining the optimal results for the desalination plant operating with 8–12 effects, with Forward Feeding and Parallel Cross Feeding. The best results are obtained for two cases: a) For a Multi Effect Desalination system with Parallel Cross Feeding operating with 12 effects, a Top Brine Temperature of 64 °C and a feed water flow rate of 293 kg/s. This configuration presents a Unit Cost of Distilled Water of 1.94 USD/m3 and 128.1 kg/s of fresh water. b) And for a Multi Effect Desalination system with Forward Feeding with 9 effects, a feed water flow rate of 380 kg/s, a Top Brine Temperature of 64 °C, which allows obtaining a Unit Cost of Distilled Water of 1.79 USD/m3. The same system but with 12 effects, a Top Brine Temperature of 72 °C, a feed water flow rate of 380 kg/s allows obtaining a higher water production of 152.3 kg/s, which shows that there is more than one optimal solution for this kind of systems, which depends on the figure to be optimized.

Pressure driven adsorption cycle integrated with thermal desalination

The canned food market is growing at an annually average rate of 3.6% due to easy access and awareness of dietary requirements, leading to a surge in water withdrawal and an estimated supply-demand gap of 40% by 2030. The conventional desalination processes are not sustainable due to high energy requirements and chemicals injection. The adsorption cycle is an emerging technology for desalination due to its temperature operation. It has many advantages over conventional desalination processes including integration synergy to improve overall performance. The conventional AD cycle processes, however, have lower performance due to inefficient packing of adsorbent in the beds and heat transfer losses to their massive heat exchangers. In this article, we propose an innovative pressure driven adsorption (PDAD) cycle to overcome conventional AD cycle limitations. In PDAD, firstly, low pressure steam is used to regenerate the adsorbent which eliminates the huge infrastructure requirement of water circulation and secondly, steam selectively extracts water vapours from pores, reducing energy consumption. We have tested the PDAD pilot and showed successful regeneration of silica gel at motive steam pressure of 2–5 bar. We also demonstrate that discharge steam from the PDAD at 65 °C can be used as a heat source for a multi effect desalination system when operating in hybrid mode to overcome its operational limitations. Our experiments show that the MED + PDAD cycle increases water production by up to 22% as compared to an earlier hybrid MEDAD cycle. The proposed system has excellent thermodynamic synergy with the combined CCGT power and desalination plant, where low-pressure bleed steam can be utilized more efficiently.

Performance analysis of an open absorption heat pump and thermal desalination system for heat and water recovery of coal-fired flue gas based on zero liquid discharge

An innovative combined system based on an open absorption heat pump and low-temperature multi-effect desalination system is proposed to provide fresh water and domestic hot water in order to achieve zero liquid discharge from coal-fired power plants and recover the waste heat of flue gas. This system takes into consideration the evaporation of desulfurization wastewater by flue gas. By using a 600 MW unit as an example, energy and exergy analysis is used to examine the impacts of flue gas humidity, temperature, mass, generator pressure, solution concentration, and boiler load on system performance. The findings showed that because coal-fired power plants produce a significant amount of dry flue gas, an increase in gas humidity has little effect on product supply. As a result, little variation in the combined system is caused by the desulfurization wastewater spray evaporation, which allows power plants to achieve zero liquid discharge with only a small loss in exergy efficiency of about 6%. The recovery of sensible heat rather than latent heat benefits from an increase in the bulk of dry flue gas. The recovery of heat and water benefits more from an increase in operating load or flue gas temperature than the open absorption heat pump system itself. The generator pressure and rich solution concentration have negligible effects on heat and water recovery. The open absorption heat pump system's increasing exergy efficiency trend and the boiler operating loads are also related. The exergy efficiency of the generator is the highest by about 75%, that of the desalination system is the lowest by about 29%, and the exergy destruction of the absorber is the highest by about 43%. The findings are likewise applicable to coal-fired power stations with various levels of electrical output.

The novel integration of biomass gasification plant to generate efficient power, and the waste recovery to generate cooling and freshwater: A demonstration of 4E analysis and multi-criteria optimization

It has long been understood that biomass energy may be utilized to transform chemical energy into electrical energy and is a renewable energy source. In this study, a unique combined cycle for generating reliable electricity from biomass chemical energy is presented and tested. In this regard, a new system is proposed based on a biomass gasifier using wood as inlet biomass and the gas turbine to utilize the synthesis gas. Also, the waste heat is recovered via a multi-effect desalination system, an absorption chiller, and a heat recovery steam generator (HRSG). The system is investigated from 4E analysis standpoints, and multi-objective optimization is conducted to seek the best solution for the proposed energy system. The results pinpoint that the compressor's pressure ratio, biomass moisture content, turbine inlet temperature (TIT), and biomass flow rate play a crucial role in the system's performance. Optimization results indicate that, at the optimal point, total exergy efficiency and pollutions are 28.32 % and 0.4797 kg / kWh, respectively.

Multi-Objective Optimization of Parallel Cross Multi-Effect Desalination Systems with Thermal Vapor Compression

Multi-Objective Optimization of Parallel Cross Multi-Effect Desalination Systems with Thermal Vapor Compression

Technoeconomic Assessment of LNG-Fueled Solid Oxide Fuel Cells in Small Island Systems: The Patmos Island Case Study

Liquefied natural gas (LNG) is regarded as the cleanest among fossil fuels due to its lower environmental impact. In power plants, it emits 50–60% less carbon dioxide into the atmosphere compared to regular oil or coal-fired plants. As the demand for a lower environmental footprint is increasing, fuel cells powered by LNG are starting to appear as a promising technology, especially suitable for off-grid applications, since they can supply both electricity and heating. This article presents a techno-economic assessment for an integrated system consisting of a solid oxide fuel cell (SOFC) stack and a micro gas turbine (MGT) fueled by LNG, that feeds the waste heat to a multi-effect desalination system (MED) on the Greek island of Patmos. The partial or total replacement of the diesel engines on the non-interconnected island of Patmos with SOFC systems is investigated. The optimal system implementation is analyzed through a multi-stage approach that includes dynamic computational analysis, techno-economic evaluation of different scenarios using financial analysis and literature data, and analysis of the environmental and social impact on the island. Specific economic indicators such as payback, net present value, and internal rate of return were used to verify the economic feasibility of this system. Early results indicate that the most sensitive and important design parameter in the system is fuel cell capital cost, which has a significant effect on the balance between investment cost and repayment years. The results of this study also indicate that energy production with an LNG-fueled SOFC system is a promising solution for non-interconnected Greek islands, as an intermediate carrier prior to the long-term target of a CO₂-free economy.