Levelized Research Articles

Optimal design of hydrogen-based storage with a hybrid renewable energy system considering economic and environmental uncertainties

Hydrogen and electricity derived from renewable sources present feasible alternative energy options for the decarbonisation of the transportation and power sectors. This study presents the utilisation of hydrogen generated from solar and wind energy resources as a clean fuel for mobility and backup storage for stationary applications under economic and environmental uncertainties. This is achieved by developing a detailed techno-economic model of an integrated system consisting of a hydrogen refuelling station and an electric power generation system using Mixed Integer Quadratic Constrained Programming (MIQCP), which is further relaxed to Mixed Integer Linear Programming (MILP). The model is implemented in the Advanced Interactive Multidimensional Modelling Software (AIMMS) and considering the inherent uncertainties in the wind resource, solar resource, costs and discount rate, the total cost of the three configurations (Hybrid PV-Wind, Standalone PV, and Standalone wind energy system) was minimised using robust optimisation technique, and the corresponding optimal sizes of the components, levelised cost of energy (LCOE), excess energy, greenhouse emission avoided, and carbon tax were evaluated. The levelised cost of the deterministic optimisation solution for all the configuration ranges between 0.0702 $/kWh to 0.0786 $/kWh, while the levelised cost of the robust optimisation solution ranges between 0.07188 $/kWh to 0.1125 $/kWh. The proposed integration has the advantages of affordable hydrogen and electricity prices, minimisation of carbon emissions and grid export of excess energy.

Techno-economic analysis and optimal sizing of hybrid PV-wind systems for hydrogen production by PEM electrolysis in California and Northern Germany

The aim of this study is to assess the economic potentials of power and hydrogen generation via solar and wind energy resources at locations in Northern Germany and California, both of these (geographical) regions being pioneers in terms of a sustainable energy transition. Based on extensive research and electrolyzer manufacturer interviews, green hydrogen generation plants are modeled in a MATLAB® environment. All relevant inputs and outputs of the systems studied (wind power plants, photovoltaic power plants, and polymer electrolyte membrane electrolyzers, among others) are considered for different locations and framework conditions. In contrast to the existing literature, special attention is paid to the part-load behavior of electrolysis systems, which becomes particularly relevant in their interplay with volatile renewables. Metrics such as the levelized costs of electricity (LCOE) of the wind and photovoltaic power plants and the resulting levelized costs of hydrogen (LCOHy) are determined. With the help of the developed model, dimensioning of a whole system's components can be determined for different locations. A case study is conducted for a Northern German site and another one for a site in the Californian Mojave Desert. Both the optimal dimensioning of the renewable energy plants and the ratio of installed wind and photovoltaic power plant capacity are strongly location-dependent. In Northern Germany, for example, lower LCOHy can be generated at higher wind power plant capacity shares and, in the Mojave Desert, be produced at higher photovoltaic power plant capacity shares. In general, with larger plants and correspondingly larger polymer electrolyte membrane electrolyzers, LCOHy are lower due to scaling effects. Following this dimensioning recommendation, the LCOHy vary between 4.5 €/kg and 5.2 €/kg in the Northern German case study and between 4.6 US$/kg and 5.3 US$/kg in the Californian one. With costs of 1–2 €/kg, gray hydrogen is still economically superior.

100% Renewable Electricity in Indonesia

The rapid fall in the cost of solar photovoltaics and wind energy offers a pathway to the deep decarbonization of energy at an affordable price. Off-river pumped hydro energy storage and batteries provide mature and large-scale storage to balance variable generation and demand while minimizing environmental and social impacts. High-voltage inter-regional interconnection and dispatchable capacity (existing hydro and geothermal) can help balance supply and demand. This work investigates an Indonesian energy decarbonization pathway using mostly solar photovoltaics. An hourly energy balance analysis using ten years of meteorological data was performed for a hypothetical solar-dominated Indonesian electricity system for the consumption of 3, 6 and 10 megawatt-hours (MWh) per capita per year (compared with current consumption of 1 MWh per capita per year). Pumped hydro provides overnight and longer storage. Strong interconnection between islands was found to be unnecessary for Indonesia, contrary to findings from similar modelling in countries at higher latitudes. Storage requirements for power and energy were found to be smaller than three kilowatts and 30–45 kilowatt-hours per person, respectively. Introducing gas turbines (burning hydrogen or synthetic methane) contributing around 1% of annual generation reduced the levelized cost of electricity (LCOE) by 14% and halved the storage requirements by allowing the system to ride through prolonged cloudy periods at lower cost. This work showed that Indonesia’s vast solar potential combined with its vast capacity for off-river pumped hydro energy storage could readily achieve 100% renewable electricity at low cost. The LCOE for a balanced solar-dominated system in Indonesia was found to be in the range of 77–102 USD/megawatt-hour.

Novel approach for optimizing wind-PV hybrid system for RO desalination using differential evolution algorithm

Access to clean water is a basic human right, and reverse osmosis (RO) is a common method for producing potable water from seawater. However, the high energy demands of RO systems make them expensive to operate. Hybrid systems that combine renewable energy sources (RES), such as wind and photovoltaic (PV) systems, can reduce the energy costs associated with powering RO systems. In this paper, a novel approach that uses a differential evolution (DE) algorithm to optimize wind-PV hybrid systems for RO desalination is proposed. (DE) is a heuristic, population-based algorithm that searches for the global optimal solution. The approach aims to minimize the levelized cost of energy (LCOE) and ensure that Desalinated water costs are within an appropriate range. The algorithm was used in a case study of the city of Dhahran, Saudi Arabia, which faces significant water scarcity challenges. The results show that for an RO load demand of 1 kW, the optimized hybrid system's configuration includes a 26 PV panels with generation capacity of 7.67 kW, 2 wind turbines with 1 kW production capacity each and 9-battery storage system with 38.79 kWh storage capacity. The LCOE is 0.39 $/kWh for Dhahran city, and the cost of desalinated water falls between 1.98 and 2.16 $/m3, which is lower than the costs reported in the literature.

Microgrids for green hydrogen production for fuel cell buses – A techno-economic analysis for Fiji

The study examines the feasibility of producing hydrogen for fuel cell buses in Fiji. The paper focuses on sizing hybrid microgrids comprising solar panels and wind turbines as the primary power source for hydrogen production while considering both off-grid and grid-connected cases. As no fuel cell vehicles exist in Fiji at present, five long-distance buses with daily travel of 380 km are proposed as a pilot scale baseline system, which would operate in the daytime only. Detailed technical and economic modelling was done using the HOMER Pro software with cost inputs derived from literature. A total of three cases for the on-grid and four cases for the off-grid systems are analyzed based on the various combinations of components. HOMER Pro optimized the grid configurations to minimize the Net Present Cost (NPC) values. All seven cases were also modelled with and without the effects of hydrogen gas compressors to emulate the production of low-pressure gas without compression and compressed high-pressure hydrogen required for fuel cell buses. It was found that a grid-connected system with solar and wind hybrid was the most feasible configuration and yielded the lowest NPC of $6 million. The grid-connected case also yielded a Levelized Cost of Electricity (LCOE) of $0.10/kWh and a Levelized Cost of Hydrogen (LCOH) of $9.08/kg with compression to 400 bars. The LCOH stood at $8.73/kg for hydrogen generation without compression. The most feasible off-grid configuration using solar and wind power attained an LCOE of $1.15/kWh while giving a LCOH of $13.00/kg for compressed hydrogen. It was also found that neglecting hydrogen compression load and costs can underestimate the LCOH by as much as 6.92 %. The off-grid best case had no CO2 produced during its operation, leading to a net zero process that offsets 929.9 tons of CO2 compared to the baseline. The grid-connected system does have some emissions but leads to a 93.9 % reduction in CO2 emissions, offsetting 873.3 tons of CO2 compared to the baseline. The study updated the cost inputs to account for inflation, logistics, and hydrogen gas compression, which are not available directly in HOMER Pro software. At the time of writing this paper, no feasibility study existed for hydrogen production in Fiji using renewable energy.

Impact of backtracking strategies on techno-economics of horizontal single-axis tracking solar photovoltaic power plants

Optimisation of horizontal single-axis tracking solar photovoltaic power plants is important for its optimal application. Commonly, standard backtracking has been applied to avoid mutual shading and improve the full load hours and levelised cost of electricity; however, this approach is not always the best solution for state-of-the-art modules with half cell technology. Backtracking has not yet been studied for different test sites with different solar and climatic conditions. This study aims to improve the knowledge on the techno-economic performance of horizontal single-axis tracking systems with half cell modules applying different backtracking strategies in full hourly resolution for nine test sites globally and varying row spacing. In addition to the standard backtracking algorithm, an advanced backtracking algorithm that varies the tracking angle only if the irradiance can be improved, and an advanced sophisticated backtracking algorithm simulating the irradiance for all possible tracking angles, are studied. The results confirm that standard backtracking is only superior for specific conditions. Compared to no backtracking, standard backtracking shows up to ca. 9% higher levelised cost of electricity due to lower full load hours. Advanced backtracking can lower the levelised cost of electricity by up to 9% and advanced sophisticated backtracking by up to 12%, due to improved full load hours. In general, results are similar and comparable for all test sites studied. This study highlights the importance of backtracking for optimised future horizontal single-axis tracking system planning.

Driving Urban Energy Sustainability: A Techno-Economic Perspective on Nanogrid Solutions

In response to technological advances, environmental concerns, and the depletion of conventional energy sources, the world is increasingly focusing on renewable energy sources (RES) as a means of generating electricity in a more sustainable and environmentally friendly manner. Türkiye, with its advantageous geographical location, long hours of sunshine, and favourable climatic conditions, has a high potential for the use of solar energy. The objective of this study was to identify an energy system that minimizes investment costs while optimizing the levelized cost of energy (LCOE) and minimizing greenhouse-gas (GHG) and carbon dioxide emissions. To achieve this, the study used the concept of nanogrids (NGs) and carried out different evaluations for electric vehicle charging stations (EVCS) at different energy levels connected to the grid. The research focused on classic apartment buildings and multistory condominium-style buildings in Istanbul, Türkiye. Using HOMER Grid 1.11.1 version software, the study identified two optimal configurations: a PV–GRID system with 7 kW photovoltaic capacity and a PV–WT–GRID system with 90 kW PV capacity and 6 kW wind-turbine capacity. These configurations had a significantly lower LCOE compared to the cost of electricity from the conventional grid. When examining the sensitivity to economic factors, it was observed that the net present cost (NPC) and LCOE values fluctuated with electricity prices, inflation rates, and equipment costs. In particular, the two optimal configurations did not include a battery energy-storage system (BESS) due to the low energy demand in the PV–GRID system and the efficiency of the wind turbines in the PV–WT–GRID system. This highlights the need to tailor energy solutions to specific consumption patterns and resource types. In conclusion, the adoption of PV–GRID and PV–WT–GRID systems in Istanbul’s urban buildings demonstrates economic viability and environmental benefits, highlighting the importance of renewable energy sources, particularly solar PV, in mitigating energy-related environmental challenges, such as reducing CO2 emissions and reducing dependence on conventional grid electricity.

Energy, Exergy and Thermoeconomic Analyses on Hydrogen Production Systems Using High-Temperature Gas-Cooled and Water-Cooled Nuclear Reactors

The use of nuclear energy is inevitable to reduce the dependence on fossil fuels in the energy sector. High-temperature gas-cooled reactors (HTGRs) are considered as a system suitable for the purpose of reducing the use of fossil fuels. Furthermore, eco-friendly mass production of hydrogen is crucial because hydrogen is emerging as a next-generation energy carrier. The unit cost of hydrogen production by the levelized cost of energy (LCOE) method varies widely depending on the energy source and system configuration. In this study, energy, exergy, and thermoeconomic analyses were performed on the hydrogen production system using the HTGR and high-temperature water-cooled nuclear reactor (HTWR) to calculate reasonable unit cost of the hydrogen produced using a thermoeconomic method called modified production structure analysis (MOPSA). A flowsheet analysis was performed to confirm the energy conservation in each component. The electricity generated from the 600 MW HTGR system was used to produce 1.28 kmol/s of hydrogen by electrolysis to split hot water vapor. Meanwhile, 515 MW of heat from the 600 MW HTWR was used to produce 8.10 kmol/s of hydrogen through steam reforming, and 83.6 MW of electricity produced by the steam turbine was used for grid power. The estimated unit cost of hydrogen from HTGR is approximately USD 35.6/GJ with an initial investment cost of USD 2.6 billion. If the unit cost of natural gas is USD 10/GJ, and the carbon tax is USD 0.08/kg of carbon dioxide, the unit cost of hydrogen produced from HTWR is approximately USD 13.92/GJ with initial investment of USD 2.32 billion. The unit cost of the hydrogen produced in the scaled-down plant was also considered.

Multi-objective optimization of supercritical CO2 Brayton cycles for coal-fired power generation with two waste heat recovery schemes

The efficiency of supercritical CO2 (sCO2) Brayton cycle (SCBC) based coal-fired power generation can be enhanced by harnessing the waste heat from sCO2 cooling and flue gas, which currently remains largely untapped. In this paper, we propose two types of design roadmap for utilizing this waste heat. The first method involves using an organic Rankine cycle (ORC) to generate additional power, while the second method utilizes LiBr/H2O absorption refrigeration cycle (ARC) to further cool down compressor inlet sCO2, and thereby reduces its compression power consumption. An energy-economic-environmental multi-criteria models are formulated to access performance of the aforementioned designs and compare them with a standalone sCO2 Brayton recompression cycle system (Standalone). The non-dominated sorting genetic algorithm II is applied to carry out the multi-objective optimization of the three systems. The results show that the SCBC-ARC system achieves the maximum thermal efficiency (ηth) and minimum environmental impact load (EIL), while SCBC-ORC system achieves the minimum levelized cost of electricity (LCOE). We also find that minimizing LCOE conflicts with maximizing ηth and minimizing EIL, respectively. The relationship between maximizing ηth and minimizing EIL is consistent, suggesting that increasing efficiency will alleviate environmental impact of the systems. We also identify and discuss balanced designs for the systems, and our results show that the ηth of SCBC-ORC and SCBC-ARC is 1.40% and 1.70% higher than the Standalone, respectively, the LCOE is 0.56% lower and 3.66% higher than Standalone, respectively, and EIL is 1.16% and 1.59% lower than the Standalone, respectively.

Techno-economic analysis of a new thermal storage operation strategy for a solar aided liquid air energy storage system

The SA-LAES system is an economical and efficient energy storage solution that combines solar energy with LAES. However, the inherent instability of solar energy can result in uncertainty regarding heat storage, thereby compromising the stability of the energy storage system. The development of more economical, efficient, and stable strategies for the SA-LAES system represents a challenging task. The present study puts forward a novel thermal storage operation scheme (Strategy 2) for SA-LAES systems integrated with electric heating during valley periods, thereby achieving long-term stable operation of the energy storage system via the alternating utilization of two full molten salt tanks and one empty molten salt tank. Theoretical and case studies are conducted based on thermodynamic and economical technical indicators, and detailed comparisons are made with the traditional strategy (Strategy 1) of only changing the solar multiple and capacity. The results show the exergy destruction of Strategy 1 mainly occurs in air turbines under off-design operating conditions. The exergy destruction of Strategy 2 is mainly in the electric heater part. The single-day analysis found that the new strategy has a more significant advantage in terms of exergy efficiency than Strategy 1 when the direct normal irradiance (DNI) is below 650 W/m2. In the case study, the levelized cost of energy (LCOE) values for Nanning, Beijing, and Hami regions in Strategy 2 are 0.118 $/kWh, 0.077 $/kWh, and 0.062 $/kWh, respectively. The LCOE values of Strategy 2 are decreased by 10.97 %, 27.49 %, and 3.40 % compared to Strategy 1, respectively. The payback periods for investments in the Beijing and Hami regions have decreased by 67.63 % and 16.41 %, respectively. The research presented in this article provides an economical, efficient, and stable operating strategy for thermal storage in the SA-LAES system.

Techno-economic feasibility analysis of a commercial grid-connected photovoltaic plant with battery energy storage-achieving a net zero energy system

Grid connected Photovoltaic (PV) plants with battery energy storage system, are being increasingly utilised worldwide for grid stability and sustainable electricity supplies. In this context, a comprehensive feasibility analysis of a grid connected photovoltaic plant with energy storage, is presented as a case study in India. A novel smart net-zero energy management system is developed to reduce grid and fossil fuel-based backup electricity consumption during power outages and peak load shaving by controlling peak load demand A life cycle cost-benefit and levelized cost of energy (LCoE) analysis, is presented for five optimised photovoltaic plants with battery energy storage systems, with and without net metering regimes. The Solar Labs and PVSyst softwares are used for system planning and energy generation estimation followed by HOMER grid software and Excel sheet-based financial models for system optimisation and cost-benefit analysis. The sensitivity analysis is carried out considering most sensitive parameters to identify the best option. The results found a 200 kWp photovoltaic plant with 250-kWh battery energy storage system with net metering, as the best-optimised option with energy generation cost of INR 4.21/kWh, with 6.15 years payback period. The study results can be followed for sustainable solar power generation for commercial grid connected PV power plants worldwide.

Green vs fossil-based energy vectors: A comparative techno-economic analysis of green ammonia and LNG value chains

This study conducts a comparative techno-economic assessment on the value chains of ammonia, as a green energy vector, and Liquefied Natural Gas (LNG), representing the benchmark energy vector, for long-distance energy transportation from Middle East to Europe. The value chain involves production from resources, conversion to an energy vector, storage and transport and reconversion of the energy vector to a suitable fuel. For comparison purposes, an electric power output of 400 MW is assumed to be produced by a power plant that utilizes either green or fossil fuels delivered to it. The adopted parameter for this comparison is the Levelized Cost of Energy (LCoE). Greenhouse gas emissions are economically penalized through the Social Cost of Carbon (SCC). Considering a SCC of 0.100 €/kg, the LCoE of the LNG value chain is 59.19 €/MWh, while that of ammonia is 231.71 €/MWh. Since the cost of producing green hydrogen and purified natural gas strongly affects the results, a sensitivity analysis is performed to assess the impact of the assumed values. The SCC required to break even the LCoE of the two value chains is: 0.183 €/MWh when considering the most favorable scenario for the green energy vector (low green hydrogen and high purified natural gas production costs) and 1.731 €/kg when considering the most unfavorable one. This study highlights the cost-effectiveness of LNG in the current economic and regulatory landscape. However, the break-even range for the SCC indicates the potential for green ammonia to gain economic viability under higher carbon pricing scenarios.

Supporting punishment via taxation in a structured population

Taxes are an essential and uniformly applied institution for maintaining modern societies. However, the levels of taxation remain an intensive debate topic among citizens. If each citizen contributes to common goals, a minimal tax would be sufficient to cover common expenses. However, this is only achievable at high cooperation level; hence, a larger tax bracket is required. A recent study demonstrated that if an appropriate tax partially covers the punishment of defectors, cooperation can be maintained above a critical level of the multiplication factor, characterizing the synergistic effect of common ventures. Motivated by real-life experiences, we revisited this model by assuming an interactive structure among competitors. All other model elements, including the key parameters characterizing the cost of punishment, fines, and tax level, remain unchanged. The aim was to determine how the spatiality of a population influences the competition of strategies when punishment is partly based on a uniform tax paid by all participants. This extension results in a more subtle system behavior in which different ways of coexistence can be observed, including dynamic pattern formation owing to cyclic dominance among competing strategies.

The role of energy storage in Great Britain's future power system: focus on hydrogen and biomass

The increasing deployment of variable renewable energy (VRE) in the power sector, such as wind and solar photovoltaic, is expected to reduce emissions. However, VRE poses challenges due to their intermittency and variability. The Future Renewable Energy Performance into the Power System Model (FEPPS) is used to analyse VRE penetration in Great Britain's (GB) power system, resulting in VRE shares of around 65%, far from over 80% forecasted by 2030 and 2040 due to flexibility and stability constraints. The incorporation of new power generation and energy storage technologies is also analysed, including the role of biomass and hydrogen as low-carbon fuel options. Hydrogen is assumed to be produced from the curtailment of VRE and biomass. Between 6.57 and 283 Mt. of biomass would be required to balance bio‑hydrogen requirements by 2040; therefore, hydrogen production would depend on technology prioritisation. Power generation from hydrogen technologies (fuel cells and turbines) has a significant role in power system decarbonisation, with hydrogen turbines meeting up to ∼10% of annual electricity demand. In contrast, generation from batteries, adiabatic compressed air energy storage and natural gas turbines is not significant. Moreover, between 7.7 and 9.7 TWh of hydrogen storage would be needed, and there is substantial potential for salt cavern storage in GB, providing many 100s TWh. Finally, incorporating new generation and storage technologies relies on levelized cost of electricity (LCOE) reductions of 31% and 13% by 2030 and 2040, respectively, to keep the power sector on track towards decarbonisation.

A coupled fluid-thermo-mechanical evaluation of various freeze recovery strategies for molten salt parabolic trough collectors

This research advances the field of Concentrating Solar Power (CSP) by offering a comprehensive assessment of freeze-recovery strategies for molten salt parabolic trough collectors, essential for the next generation of CSP plants. Employing a cutting-edge transient 3D Conjugate Heat Transfer (CHT) model, the research elucidates the significant yet previously underestimated role of natural convection in the phase transition of solidified salts. The study demonstrates that the strategic inclusion of impedance heating not only accelerates the defrosting process but also minimizes thermal stresses within the absorber tubes, ensuring mechanical integrity. Moreover, the dual-method approach, which combines solar and impedance heating, reveals a potential to improve the Levelized Cost of Electricity (LCOE) by 4% annually following a complete freeze event. The research conclusively suggests that this synergistic strategy could yield substantial operational cost savings while maintaining the structural robustness of CSP systems. The presented findings provide a detailed blueprint for enhancing plant resilience and economic viability, opening new avenues for operational excellence in CSP technology.

Multi-objective optimization application for a coupled light water small modular reactor-combined heat and power cycle (cogeneration) systems

The goal of this research is to propose a way to maximize small modular reactor (SMR) utilization to gain better market feasibility in support of carbon neutrality. For that purpose, a comprehensive tool was developed, combining off-design thermohydraulic models, economic objective models (levelized cost of electricity, annual profit), non-economic models (saved CO2), a parameter input sampling method (Latin hypercube sampling, LHS), and a multi-objective evolutionary algorithm (Non-dominated Sorting Algorithm-2, NSGA2 method) for optimizing a SMR-combined heat and power cycle (CHP) system design. Considering multiple objectives, it was shown that NSGA2+LHS method can find better optimal solution sets with similar computational costs compared to a conventional weighted sum (WS) method. Out of multiple multi-objective optimal design configurations for a 105 MWe design generation rating, a chosen reference SMR-CHP system resulted in its levelized cost of electricity (LCOE) below $60/MWh for various heat prices, showing economic competitiveness for energy market conditions similar to South Korea. Examined economic feasibility may vary significantly based on CHP heat prices, and extensive consideration of the regional heat market may be required for SMR-CHP regional optimization. Nonetheless, with reasonable heat market prices (e.g. district heating prices comparable to those in Europe and Korea), SMR can still become highly competitive in the energy market if coupled with a CHP system.

Assessing levels of urban public electric vehicle charging service in different-level cities: A case study of the 35 cities of the Chengdu–Chongqing Urban Agglomeration, China

Urban Public Electric Vehicle Charger (PEVC) services are crucial for sustainable development in countries with low rates of single-family home ownership, promoting vehicle electrification and contributing to the achievement of the Sustainable Development Goals (SDGs). PEVC provision differs across Chinese regions and cities, especially among various city levels. However, this disparity has not been adequately addressed, impeding strategic PEVC development planning. To clarify these disparities, this study combines an analysis of the supply-demand and usage costs of PEVCs, which are the main factors affecting vehicle electrification, and evaluates the disparities in PEVC service among 35 cities of varying levels in Chengdu–Chongqing Urban Agglomeration. The results indicate that mega-cities demonstrate the highest service levels, attributed to their robust supply capacity and well-developed pricing mechanisms, but they also face higher actual demand pressures. Medium-sized and small cities show intermediate PEVC service, while large cities unexpectedly demonstrate the lowest supply-demand level and highest usage costs due to the mismatch between PEVC supply and demand size. Additionally, the study highlights the priority of PEVC station scale in enhancing the supply. These findings inform policymakers in shaping targeted strategies and policies, adapting to the varying PEVC service levels across different cities.

Management of Hybrid Wind and Photovoltaic System Electrolyzer for Green Hydrogen Production and Storage in the Presence of a Small Fleet of Hydrogen Vehicles—An Economic Assessment

Nowadays, with the need for clean and sustainable energy at its historical peak, new equipment, strategies, and methods have to be developed to reduce environmental pollution. Drastic steps and measures have already been taken on a global scale. Renewable energy sources (RESs) are being installed with a growing rhythm in the power grids. Such installations and operations in power systems must also be economically viable over time to attract more investors, thus creating a cycle where green energy, e.g., green hydrogen production will be both environmentally friendly and economically beneficial. This work presents a management method for assessing wind–solar–hydrogen (H2) energy systems. To optimize component sizing and calculate the cost of the produced H2, the basic procedure of the whole management method includes chronological simulations and economic calculations. The proposed system consists of a wind turbine (WT), a photovoltaic (PV) unit, an electrolyzer, a compressor, a storage tank, a fuel cell (FC), and various power converters. The paper presents a case study of green hydrogen production on Sifnos Island in Greece through RES, together with a scenario where hydrogen vehicle consumption and RES production are higher during the summer months. Hydrogen stations represent H2 demand. The proposed system is connected to the main power grid of the island to cover the load demand if the RES cannot do this. This study also includes a cost analysis due to the high investment costs. The levelized cost of energy (LCOE) and the cost of the produced H2 are calculated, and some future simulations correlated with the main costs of the components of the proposed system are pointed out. The MATLAB language is used for all simulations.

Energy, economic, and environmental (3E) performance assessment, comparison, and analysis of airport cargo terminal microgrid system under the islanded and grid-connected modes

Microgrids, which can be grid-connected or isolated, may experience dependability issues as a result of intermittent renewable energy. The implementation of a hybrid renewable energy system (HRES) could alleviate this problem but is still a challenging task because of its interference, uncertain, and unpredictable nature. Currently, the absence of comprehensive assessment impedes large-scale applications. In this study, a novel 3E assessment method-based complete quantitative assessment is suggested and inventively integrated with a newly proposed triangle evaluation scheme. Loads of an airport cargo terminal, which are used to test the assessment approach, are classified into critical and non-critical categories according to their necessity. The microgrid system flexibility is considered by the trade-off of non-critical loads. Results show that the assessment method is more intuitive in quantifying the system's performance. The Levelized Cost of Energy (LCOE) in the islanded mode is lower than the current electricity price (from 0.5407 to 0.5439 CNY/kWh) and the annual carbon emission is reduced to one-third of that in the grid-connected mode. Its flexibility can effectively reduce dependence on backup power generation, where the daily peak shedding increases from 217.88 kW to 555.04 kW and daily hours without charging from 6.7 h to 8.9 h. The carbon emission decreases by 32 % considering the impacts of the system flexibility. Besides, the critical distance exists when the LCOE exceeds the current market electricity price.

Techno-Economic Feasibility Study of a 1.5 MW Grid-Connected Solar Power Plant in Bangladesh

This study addresses the pressing energy constraints in nations like Bangladesh by proposing the implementation of photovoltaic (PV) microgrids. Given concerns about environmental degradation, limited fossil fuel reserves, and volatile product costs, renewable energy sources are gaining momentum globally. Our research focuses on a grid-connected solar PV system model at Char Jazira, Lalpur, Natore, Rajshahi, Bangladesh. Through PVsyst 7.1 simulation software, we assess the performance ratio (PR) and system losses, revealing an annual solar energy potential of 3375 MWh at standard test condition (STC) efficiency. After considering losses, the system generates 2815.2 MWh annually, with 2774 MWh exported to the grid. We analyze an average PR of 78.63% and calculate a levelized cost of energy (LCOE) of 2.82 BDT/kWh [1 USD = 110 BDT]. The financial assessment indicates a cost-effective LCOE for the grid-connected PV system, with an annual gross income of 27,744 kBDT from selling energy to the grid and operating costs of 64,060.60 BDT/year. Remarkably, this initiative can prevent 37,647.82 tCO2 emissions over the project’s 25-year lifespan.