Lowest Levelized Cost Of Electricity Research Articles

A Comparative Study of Floating and Ground-Mounted Photovoltaic Power Generation in Indian Contexts

The escalating global demand for energy and growing environmental concerns have stimulated the development of renewable energy-based power systems. In this context, solar power has gained significant attention, notably in the form of floating photovoltaic systems. These systems, installed on water bodies, not only boost efficiency but also reduce water evaporation from reservoirs. This research explores the power generation capabilities of floating photovoltaic systems in comparison to ground-mounted photovoltaic systems, considering a 250-watt monocrystalline photovoltaic panel. This study utilizes typical meteorological year data to comprehensively analyze four distinct locations in India. By using a single-diode model, this study finds that floating photovoltaic systems provide 6-7% more power output than ground-mounted photovoltaic systems. This efficiency gain is because the floating photovoltaic panels operate at a lower temperature (4-6°C) than their ground-mounted photovoltaic counterparts, positively influencing the overall performance. Furthermore, the degradation and soiling of ground-mounted photovoltaic and floating photovoltaic systems were also compared. The financial analysis reveals that ground-mounted photovoltaic systems typically have a lower levelized cost of electricity and shorter payback periods. Even though the financial indicators of floating photovoltaic systems are not favorable compared to ground-mounted photovoltaic systems, these results show how vital floating photovoltaic technology is for achieving the United Nations’ Sustainable Development Goals and how it could be used as an efficient technique to reduce land requirements for solar photovoltaic solutions in various geographical conditions.

Comparative Techno-Economic Analysis of Parabolic Trough and Linear Fresnel Collectors with Evacuated and Non-Evacuated Receiver Tubes in Different Geographical Regions

In the context of Concentrated Solar Power (CSP) technology, this paper presents a comparison between the Parabolic Trough Collector (PTC) and the Linear Fresnel Collector (LFC), considering both evacuated and non-evacuated receiver tubes. The comparison was carried out in terms of the Levelized Cost of Electricity (LCOE) considering a reference year and four locations in the world, characterized by different levels of direct normal irradiation (DNI) from 2183 kWh/m2/year to 3409 kWh/m2/year. The LCOE depends on economic parameters and on the net energy generated by a plant on an annual basis. The latter was determined by a steady-state 1D model that solved the energy balance along the receiver axis. This model required computing the incident solar power and heat losses. While the solar power was calculated by an optical ray-tracing model, heat losses were computed by a lumped-parameter model developed along the radial direction of the tube. Since the LFC adopted a secondary concentrator, no conventional correlation was applicable for the convective heat transfer from the glass cover to the environment. Therefore, a 2D steady-state CFD model was also developed to investigate this phenomenon. The results showed that the PTC could generate a higher net annual energy compared to the LFC due to a better optical performance ensured by the parabolic solar collector. Nevertheless, the difference between the PTC and the LFC was lower in the non-evacuated tubes because of lower heat losses from the LFC receiver tube. The economic analysis revealed that the PTC with the evacuated tube also achieved the lowest LCOE, since the higher cost with respect to both the LFC system and the non-evacuated PTC was compensated by the higher net energy yield. However, the non-evacuated LFC demonstrated a slightly lower LCOE compared to the non-evacuated PTC since the lower capital cost of the non-evacuated LFC outweighed its lower net annual energy yield. Finally, a sensitivity analysis was conducted to assess the impact on the LCOE of the annual optical efficiency and of the economic parameters. This study introduces key technical parameters in LFC technology requiring improvement to achieve the level of productivity of the PTC from a techno-economic viewpoint, and consequently, to fill the gap between the two technologies.

Understanding Solid Oxide Fuel Cell Hybridization: A Critical Review

A holistic literature review of 399 articles is presented on hybrid solid oxide fuel cell (SOFC) systems and taxonomized through a unique classification methodology that considers primary energy sources, component configurations, system outputs and relevant analysis. In the reviewed research articles, primarily four different types of technologies are used to complement the energy production of the fuel cell stack. As a result, four respective categories were established in terms of the coupling components, inclusive of (1) wind turbines (WTs), (2) solar systems (SS), (3) thermal power plant turbines (TPPTs) and (4) piston engines (PEs). Additional classification was needed to further subdivide the evaluated system configurations, due to the wide spectrum of system outputs encountered in the reviewed literature. That involved (a) electrical power generation (PG), (b) four types of cogeneration (CG), (c) four types of trigeneration (TG) and (d) two types of multigeneration (MG). Depending on the type of assessment in respective research, literature was further categorized as computational, experimental, or both computational and experimental. The most prevalent hybrid system amongst the 102 designs, as adapted from the reviewed literature, is the SOFC/gas turbine (GT) application, with the overwhelming majority producing exclusively electrical power output. The particular system is physically demonstrated in an existing 220-kW experimental facility established by the National Fuel Cell Research Center (NFCRC). The identified systems were predominantly computationally examined and research focused on operating conditions around specific design load ratings. Energy, exergy, economic, and environmental assessments were typically followed by sensitivity studies in the reviewed literature. The primary decision variables in most cases revolved around SOFC operating conditions, such as temperatures over 1000 °C as well as elevated pressures. Those resulted in the deterioration of the electrochemical cell and failed to be addressed by the majority of encountered studies. Improvements in the conversion efficiency of PG applications were enabled by natural gas (NG)-fed pressurized SOFCs, directly coupled to GTs. The most efficient power configuration in terms of thermodynamic performance was achieved by coupling PEs to SOFCs and a metal hydride reactor (MHR) to unlock a maximum net system efficiency of 79.54%. CG systems integrating solar cells (SCs) and photovoltaic panels (PVs) to SOFC subsystems can result in a combined efficiency of approximately 90% and sustain this over a broad energy demand range. TG systems incorporating gasifiers to SOFC/GT subsystems achieved a combined efficiency of 93%, whereas the optimal combined efficiency in MG configurations was identified at 79.5% by coupling SCs to the SOFC/GT/organic Rankine cycle turbine (ORCT) subsystems. In terms of cost-effectiveness, configurations that relied on increasing levels of renewable energy (RE) technologies resulted in high overall levelized cost of electricity (LCOE). This cost was increased further when power storage units were deployed to address wind and solar intermittency challenges. Configurations classified under TPPTs operating on low carbon-content fuels were preferred in terms of providing lower LCOE, while applications operating on gasified biomass and coal blends should deploy additional CO2 capture and storage units to mitigate respective emissions.

Comparative Analysis of Hybrid Geothermal-Solar Systems and Solar PV with Battery Storage: Site Suitability, Emissions, and Economic Performance

Renewable energy integration has become a critical focus in the global effort to reduce carbon emissions and diversify energy sources. In regions with distinct geographic features, such as Türkiye, combining different renewable technologies can offer enhanced energy security. This study investigates the site suitability and economic and environmental performance of hybrid geothermal-solar systems and solar PV systems with battery storage across the provinces of Osmaniye, Hatay, and Kilis, of Türkiye. Using the fuzzy-AHP method, site suitability is evaluated, addressing a key gap in comparing these systems' adaptability to varying geographic conditions. This study is the first to directly compare these two renewable energy technologies in terms of site suitability. The findings reveal significant differences in site suitability, with solar PV systems with battery storage demonstrating broader applicability across the region. The suitable sites (20-100% suitability) cover 1260.82 km² for solar PV systems with battery storage and only 122.18 km² for hybrid geothermal-solar systems. In terms of environmental impact, hybrid geothermal-solar systems exhibit significantly lower carbon emissions, averaging 44.6 kg CO₂/MWh, compared to 123.8 kg CO₂/MWh for solar PV systems with battery storage. Economically, hybrid geothermal-solar systems also outperform with a lower levelized cost of electricity of $0.091/kWh versus $0.254/kWh for solar PV systems. These results highlight the environmental and economic advantages of hybrid geothermal-solar systems, while also emphasizing their limited scalability to regions with geothermal activity. Conversely, solar PV systems, despite their higher emissions and costs, offer greater flexibility and potential for widespread deployment.

Performance and Parametric Studies of a Non-Compact Hybrid PV-CSP Power Plant Integrated by a Supercritical Rankine Cycle and an Electric Heater in Series

This study focuses on performing a parametric analysis of the non-compact concentrated solar power (CSP)-photovoltaic (PV) hybrid plant combined with an electric heater (EH) and a Supercritical Rankine Cycle as well as a multi-objective optimization of different technologies. The power plant sizing is evaluated in a baseload dispatch scenario of 165 MWe for a location in Seville and considering combinations of the PV installed power, CSP solar multiple (SM), thermal energy storage (TES) capacity and EH power. Studied parametric combinations are optimized for minimizing the Levelized Cost of Electricity (LCOE) and maximizing the capacity factor (CF), with the ultimate goal of achieving the Pareto front. The results of the study show that certain combinations, such as PV=450 MWe, SM=2, EH=250 MW, and TES=12 h, have a favourable balance between the LCOE and the CF (LCOE=0.0979 €/kWh, CF=0.702). In addition, the results obtained through the optimization process, in particular by considering the Pareto frontier, indicate that among the different technologies, the CSP-PV-TES-EH configuration has the lowest LCOE and the highest FC.

Enhancing the integration of PV and coal-fired power plant for low-carbon, low-cost, and reliable power supply through various energy storage systems

The integration of photovoltaic (PV) system and coal-fired power plants (CFPP) through various energy storage systems (ESS) presents a promising strategy for achieving a low-carbon, low-cost, and reliable power supply. This study proposes a low-carbon power system that deeply integrates PV and CFPP through battery, thermal, and ammonia energy storage system (BESS, TESS, AESS). Multi-objective optimizations were conducted to minimize both the levelized cost of electricity (LCOE) and specific CO2 emission while considering constraints related to power supply reliability. Additionally, the influence of technological advancements on reducing LCOE was explored, providing insights into the developmental pathways of these energy storage technologies. The results indicate that: (1) The optimal selection of ESS is related to CO2 emission reduction targets. For less restrictive targets, it is economical to abandon ESS and rely entirely on PV and CFPP. As emission reduction targets progress, TESS becomes economically optimal. In scenarios with strict targets, BESS becomes economically optimal. (2) The combination of PV+CFPP+MultiESS demonstrates superior cost-effectiveness under high-reliability constraints, exhibiting a 7.6 % lower LCOE compared to PV+CFPP+SingleESS at a reliability level of ≥ 99 %. (3) Compared to CFPP retrofitted with CCS, the PV+CFPP+ESS integrated system is more economically favorable for less restrictive CO2 emission reduction targets. However, as the CO2 emission limits become stricter, the CCS-retrofitted technology becomes more economically favorable. (4) To enhance cost-competitiveness, developments should be directed toward reducing the unit investment cost of storage for BESS, while reducing the unit investment cost of power conversion system for AESS. As for TESS, technological advancements across various aspects can effectively contribute to its cost-competitiveness.

Comparative analysis of solar module configuration and tracking systems for enhanced energy generation in South Sakucia Union, Bhola, Bangladesh: A software based analysis

Bangladesh is blessed with an extensive range of solar energy generation possibilities; however, the primary impediment to attaining its full potential in the solar energy industry is the inadequate budget in the energy sector. As a result, determining the most economical and efficient solar module configuration for each specific scenario has become a critical necessity. This study offers a comprehensive techno-economic analysis and environmental impact assessment of four distinct solar modules: monofacial, bifacial, dual-axis solar tracker, and seasonal tilt solar module, in an open area of South Sakucia Union, Bhola district, in the southwest part of Bangladesh. By integrating energy-generation capabilities, financial metrics, and environmental benefits, this research provides a holistic evaluation framework to ensure optimal economic performance and minimal adverse environmental effects for sustainable solar solutions in Bangladesh. Utilizing PV*SOL, PVsyst, and System Advisor Model (SAM) software, this study assesses energy-generation capabilities and economic viability. Despite the dual-axis solar tracker exhibiting the highest average energy generation (149,070.3 kWh/year), its higher initial cost renders it less financially viable compared to other configurations. Financial metrics reveal that the seasonal tilt configuration is the most cost-efficient, with the lowest Levelized Cost of Electricity (LCOE) at $0.0452/kWh and the highest Net Present Value (NPV) of $52,887.70. Additionally, it has the shortest Discounted Payback Period (DPBP) at 12.69 years, a favorable Internal Rate of Return (IRR) of 9.460 %, and a Profitability Index (PI) of 1.459, indicating robust returns on investment. These findings emphasize the importance of considering both energy-generation capabilities and financial metrics when evaluating solar module configurations in the southern part of Bangladesh, serving as a valuable reference for policymakers. Moreover, meticulous environmental impact assessments assist in choosing configurations with minimal adverse effects on the environment.

Machine learning assisted prediction for hydrogen production of advanced photovoltaic technologies

The photovoltaic (PV) water electrolysis method currently stands as the most promising approach for green hydrogen production. The rapid iteration of photovoltaic technologies has significantly affected on the technical and economic evaluation for photovoltaic hydrogen production. In this work, the photovoltaic hydrogen production of three most advanced silicon photovoltaic technologies is systematically compared for the first time under the climatic conditions of the Kucha region. All-weather stable hydrogen production control system with optimal charging and discharging strategies is constructed to realize stable and efficient hydrogen energy production. Seven machine learning (ML) algorithms are used to forecast the performance in power generation and hydrogen production of a 100 ​MW photovoltaic hydrogen production and energy storage (PH-S) system throughout its operational life. The long short-term memory (LSTM) algorithm exhibits the best performance, achieving mean absolute error (MAE) of 0.0415, root mean square error (RMSE) of 0.0891, and coefficient of determination (R2) of 0.8402. In terms of cost-effectiveness, heterojunction with intrinsic thin layer (HJT) PV technology achieves the lowest levelized cost of electricity (LCOE) and hydrogen (LCOH) at 0.025 $/kWh and 6.95 $/kg, respectively. According to the sensitivity analysis, when the cost of proton exchange membrane electrolysis (PEMEC) reduced 50%, the LCOH for PH-S system decreased 21.40%. This study provides valuable insights for the practical implementation of large-scale photovoltaic hydrogen production and cost reduction in PH-S systems.

Techno-Economic Assessment of Molten Salt-Based Concentrated Solar Power: Case Study of Linear Fresnel Reflector with a Fossil Fuel Backup under Saudi Arabia’s Climate Conditions

Concentrated solar power (CSP) has gained traction for generating electricity at high capacity and meeting base-load energy demands in the energy mix market in a cost-effective manner. The linear Fresnel reflector (LFR) is valued for its cost-effectiveness, reduced capital and operational expenses, and limited land impact compared to alternatives such as the parabolic trough collector (PTC). To this end, the aim of this study is to optimize the operational parameters, such as the solar multiple (SM), thermal energy storage (TES), and fossil fuel (FF) backup system, in LFR power plants using molten salt as a heat transfer fluid (HTF). A 50 MW LFR power plant in Duba, Saudi Arabia, serves as a case study, with a Direct Normal Irradiance (DNI) above 2500 kWh/m2. About 600 SM-TES configurations are analyzed with the aim of minimizing the levelized cost of electricity (LCOE). The analysis shows that a solar-only plant can achieve a low LCOE of 11.92 ¢/kWh with a capacity factor (CF) up to 36%, generating around 131 GWh/y. By utilizing a TES system, the SM of 3.5 and a 15 h duration TES provides the optimum integration by increasing the annual energy generation (AEG) to 337 GWh, lowering the LCOE to 9.24 ¢/kWh, and boosting the CF to 86%. The techno-economic optimization reveals the superiority of the LFR with substantial TES over solar-only systems, exhibiting a 300% increase in annual energy output and a 20% reduction in LCOE. Additionally, employing the FF backup system at 64% of the turbine’s rated capacity boosts AEG by 17%, accompanied by a 5% LCOE reduction. However, this enhancement comes with a trade-off, involving burning a substantial amount of natural gas (503,429 MMBtu), leading to greenhouse gas emissions totaling 14,185 tonnes CO₂ eq. This comprehensive analysis is a first-of-a-kind study and provides insights into the optimal designs of LFR power plants and addresses thermal, economic, and environmental considerations of utilizing molten salt with a large TES system as well as employing natural gas backup. The outcomes of the research address a wide audience including academics, operators, and policy makers.

Assessment of wind energy resource in the western region of Somaliland

As the population of Somaliland continues to grow rapidly, the demand for electricity is anticipated to rise exponentially over the next few decades. The provision of reliable and cost-effective electricity service is at the core of the economic and social development of Somaliland. Wind energy might offer a sustainable solution to the exceptionally high electricity prices. In this study, a techno-economic assessment of the wind energy potential in some parts of the western region of Somaliland is performed. Measured data of wind speed and wind direction for three sites around the capital city of Hargeisa are utilized to characterize the resource using Weibull distribution functions. Technical and economic performances of several commercial wind turbines are examined. Out of the three sites, Xumba Weyne stands out as the most favorable site for wind energy harnessing with average annual power and energy densities at 80 m hub height of 317 kW/m2 and 2782 kWh/m2, respectively. Wind turbines installed in Xumba Weyne yielded the lowest levelized cost of electricity (LCOE) of not more than 0.07 $/kWh, shortest payback times (i.e., less than 7.2 years) with minimum return on investment (ROI) of approximately 150%.

Numerical analysis and ANN performance prediction of solar composite ventilation wall for built environment regulation

With the aim to achieve winter heating, summer heat insulation and year-round power generation as well as indoor pollutant purification, photovoltaic (PV) combined with phase change heat storage technology is ingeniously embedded in an adjustable solar composite ventilation wall with entire room model (SPVW-PV/PCM) in this study. Then, the effects of key parameters e.g. PCM melting temperature Tm and PV coverage ratio Cr on solar energy conversion and utilization with indoor environment creation are comprehensively illustrated by indoor temperature, exergy efficiency as well as power generation amount. In addition, to further clarify the application potential of the proposed model applied in different typical places in China, the artificial neural network (ANN) has been rarely adopted to predict the annual heating amount, power generation as well as its economic and environmental benefits. Research results show that the three numerical submodels closely align with previously published results, with only minor discrepancies observed in the decoupling model regarding Cout, vroom and PCM melt fraction, well within acceptable numerical tolerances of 9.87% RMSE. The thermal performance is significantly influenced by the key parameters of Tm and Cr, with at least 110 min of advance heating start-up time revealed, and excellent indoor temperature improvement of 1.59 K and 3.02 K are achieved in the heating season at Tm = 318 K or Cr = 0 % simulated group. The highest annual total energy conversion of 1367.39 kWh is surveyed in Guangzhou, corresponding to the lowest levelized cost of electricity (LCOE) of 0.18 $/kWh and the highest CO2 saving cost of 19.03 $/year. The total energy conversion effect and the CO2 saving cost can be effectively improved by 13.88 % and 13.82 % in Guangzhou, respectively, compared to the coupling off-grid PV and conventional wall in building. These research findings offer valuable insights for optimizing the design of SPVW-PV/PVM in indoor environmental construction and enhancing its overall applicability.

Comprehensive onshore wind energy assessment in Malawi based on the WRF downscaling with ERA5 reanalysis data, optimal site selection, and energy production

Malawi, despite its minimal CO2 emissions, faces huge climate impacts and a low electrification rate. Recognizing these challenges, this study presents a comprehensive and nationwide assessment of Malawi's wind energy potential, leveraging the high-resolution capabilities of the Weather Research and Forecasting (WRF) model. Unlike most site-specific studies, this study covers the entire country, factoring in different turbine hub heights. Through sensitivity analysis, the optimal configuration for the WRF model in Malawi was determined and ERA5 reanalysis data was used for initial and boundary conditions. The study's findings were validated using MERRA-2 reanalysis and actual observational datasets. A combination of GIS and the fuzzy analytic hierarchy process (AHP) was employed, integrating key factors like land use and topographical complexity to determine optimal wind farm sites. Notably, the wind suitability map uncovered significant potential for wind farm development. Furthermore, in the evaluation of a 50 MW wind farm, 80 m hub heights consistently outperformed 100 m elevations, both technically and economically. An 80 m wind farm at Site A can potentially power up to 32,931 urban and 84,475 rural households. Economically, 80 m hub heights showcased lower levelized cost of electricity (LCOE) values and faster payback periods than 100 m ones. Furthermore, these proposed wind projects can markedly reduce CO2 emissions, positioning Malawi in tandem with global sustainability aspirations. Overall, this study provides a key foundation for Malawi's renewable energy strategies, highlighting the potential for improved electrification and better climate change mitigation outcomes.

Scaling up 3D printed hybrid sorbents towards (cost) effective post-combustion CO2 capture: A multiscale study

A 3D-printed sorbent containing polyethylene-imine and multi-walled carbon nanotubes (PEI-MWCNT) was studied for post-combustion carbon capture. In this work, the adsorbent was printed on a kg scale and characterized for CO2 adsorption through lab experiments. A 6-step VSA process was simulated using the lab data to capture CO2 from a representative 800 MW power plant. The adsorbent captured >70 % of the CO2 and 95 % CO2 purity was achieved. The levelized cost of electricity (LCOE) was 130.2 $/MWh and the costs of CO2 captured and avoided were 80 and 100.12 $/tonne. However, a zeolite 13X-activated carbon (13X-AC) monolith achieved a lower LCOE of 118.1 $/MWh, with the captured and avoided costs being 63 and 78.4 $/tonne, respectively. The LCOE value for the 13X-AC monolith was 5.1 % lower than a reference-packed bed system with Zeolite 13X pellets. The corresponding cost values were lower by 9.1 % and 13.9 %, respectively for the costs of CO2 captured and avoided. The lab experiments on the PEI-MWCNT sorbent revealed that further work is necessary to improve the thermal stability and stability with long-term storage of the precursor paste.

Toward the Commercialization of Perovskite Solar Modules.

Perovskite (PVSK) photovoltaic (PV) devices are undergoing rapid development and have reached a certified power conversion efficiency (PCE) of 26.1% at the cell level. Tremendous efforts in material and device engineering have also increased moisture, heat, and light-related stability. Moreover, the solution-process nature makes the fabrication process of perovskite photovoltaic devices feasible and compatible with some mature high-volume manufacturing techniques. All these features render perovskite solar modules (PSMs) suitable for terawatt-scale energy production with a low levelized cost of electricity (LCOE). In this review, the current status of perovskite solar cells (PSCs) and modules and their potential applications are first introduced. Then critical challenges are identified in their commercialization and propose the corresponding solutions, including developing strategies to realize high-quality films over a large area to further improve power conversion efficiency and stability to meet the commercial demands. Finally, some potential development directions and issues requiring attention in the future, mainly focusing on further dealing with toxicity and recycling of the whole device, and the attainment of highly efficient perovskite-based tandem modules, which can reduce the environmental impact and accelerate the LCOE reduction are put forwarded.

Thermodynamic and Economic Analysis of a Standalone Supercritical Thermal Power Plant Integrated with Molten Carbonate Fuel Cell

A detailed technoeconomic analysis of a standalone steam cycle integrated with molten carbonate fuel cell and an organic Rankine cycle is presented herein. The modeling and thermodynamic analysis of the proposed plant is performed using a commercially available software tool called Cycle Tempo. The response surface methodology tool is employed to develop regression models to predict the plant's energy, exergy efficiencies, and levelized cost of electricity (LCOE) for varying independent factors: fuel utilization factor (uf) CO2 utilization factor (ϕ), and current density (i) of the fuel cell. The response surfaces developed from the models are used to conduct the parametric analyses on the plant. The desirability test performed for multiobjective optimization has shown the optimum plant configuration, with higher energy, exergy efficiencies, and a lower LCOE is obtained for uf = 0.85, ϕ = 60%, and i = 1000 A m−2 With an intent to reduce CO2 emissions, monoethanolamine‐based carbon capture system is implemented to the plant configuration, that exhibits maximum energy efficiency for ϕ = 90%, and results in an LCOE of 6.53 Rs kWh−1.

Analysis on data center power supply system based on multiple renewable power configurations and multi-objective optimization

With rapid development of data center industry, achieving low energy consumption and costs become important. How to provide an optimal configuration on renewable distributed energy systems combining data centers is challenging. This work discussed possible hybrid configurations by combining diesel, photovoltaic, wind, and battery capacity in data center. For each mode, renewable penetration (RP) and the Levelized Cost of Electricity (LCOE) were used to evaluate the performance of system. A multi-objective optimization analysis of the case is performed based on the entropy weighted-TOPSIS method, genetic algorithm, and NSGA-II aiming to obtain both a high RP and a low LCOE. Then, comparative research on optimal power configuration with conventional or renewable energy was conducted. The results show that it is recommended to take a high-rated PV power. When wind power is taken, it is only meaningful when combined with PV power system. For the hybrid renewable power system without an energy storage unit, it's easy to realize a lower LCOE compared to Diesel mode, and its realizable maximum RP is 28.31 %. When battery energy storage is taken in the hybrid system, six optimal configurations are recommended which can achieve the lowest cost of 0.21 $/kWh and the highest RP of 44.5 %.

Enhanced methanol reforming gas fuel cell system with electrochemical hydrogen pump: Conceptual design, system analysis, and multi-objective optimization

In this work, two methanol-reforming gas fuel cell systems coupled with an electrochemical hydrogen pump (EHP), namely, EHP pre-coupling and post-coupling fuel cell systems were proposed to achieve performance enhancement. A back propagation neural network surrogate model was established for the two systems to accurately describe system behavior, and a second-generation multi-objective non-dominated genetic algorithm was utilized for addressing the multi-objective optimization problem encompassing net output power, carbon mass-specific emission and the levelized cost of electricity. The linear non-weighted multi-attribute preference and technique for order preference by similarity to ideal solution multi-attribute decision-making methods were employed to select the optimal solutions. The optimized EHP pre-coupling fuel cell system exhibited lower carbon emissions (0.69 kgCO2/(kW·h)) and higher net output power (126.02 kW) compared to previous studies. While the EHP post-coupling system achieves a lower levelized cost of electricity (0.36 USD/(kW·h)), and stronger system stability (total efficiency reduction less 1 %). Both EHP-coupling systems offer viable process enhancements for fuel cell systems.

Energy storage as a service to achieve a required reliability level for renewable-rich standalone microgrids

Energy storage systems (ESSs) can help to reduce the intermittency and uncertainty of renewable energy supplies in power systems. ESSs are critical components of renewable-rich standalone microgrids (SMGs) to balance power generation and load demand, which is referred to as reliability. To achieve the same level of reliability as conventional power systems for renewable-based SMGs, significant investment in ESSs is required. However, due to the high investment costs of ESSs, the installation of large ESSs will not result in an affordable solution for achieving renewable SMG at the required reliability. As a result, this paper proposes a new sharing concept for ESS, namely energy storage as a service (ESaaS), to be implemented across microgrids as a low-cost alternative for improving reliability. In the proposed ESaaS concept, microgrids can use ESS from an ESS provider as required for different timeframes such as monthly, weekly, or daily, depending on the renewable resources and load profile characteristics. In this paper, the use of ESaaS is investigated over a range of timeframes for a 100 % renewable-based SMG with photovoltaic (PV), wind turbine (WT), and ESS. The SMG reliability is evaluated using Monte Carlo simulation both before and after the ESaaS strategy has been implemented. To evaluate the ESaaS affordability in improving the reliability of an SMG, this paper proposes the criteria of marginal cost of reliability, which indicates the rate of additional investment amount per percentage of reliability improvement. The marginal cost of reliability combines the economic and technical aspects of ESaaS in one simple criterion for effective decision-making among investment strategies such as different timeframes of ESaaS or permanent ESS. The simulation results show the ESaaS based on daily contract results in a lower marginal cost of reliability for the case study. To validate the effectiveness of the proposed ESaaS approach using marginal cost of reliability, the levelized cost of electricity (LCOE) is also calculated for different strategies of reliability improvement. The results confirm that the lowest LCOE is obtained using the strategy that provides the lowest marginal cost of reliability for the case study. In addition, a sensitivity analysis is performed to assess the difference in marginal cost of reliability under various uncertainties associated with the installed capacity of PV and WT, and the cost of utilising the ESaaS.

Experimental Investigation of a Small-Scale Parabolic Trough Concentrated Solar Power ‎Systems

Large-scale systems have a lower levelized cost of electricity than small-scale concentrated solar power systems. Thus, the purpose of the present study is to evaluate the potential of using standalone small-‎scale ‎concentrated ‎solar power collectors in order to generate process ‎heat ‎at ‎a ‎moderate ‎temperature, which directly utilizes thermal energy without the need to generate electricity. ‎A ‎parabolic trough ‎collector (3.6m2) ‎was ‎designed ‎and ‎manufactured, including a dual-axis solar tracking system with and without an insulating function. An ‎insulating ‎cavity ‎was incorporated to ‎minimize the heat ‎losses collected by the absorbed ‎tube. ‎The experiments ‎were ‎carried out during a time of high winds and unfavorable weather ‎in ‎Sabratha City. The findings of the experiments demonstrated that the produced temperature and the collected heat energy progressively increase until they reach their maximum value, and then gradually decrease. The maximum water ‎temperature ‎was 96ºC at ‎a ‎flow rate ‎of ‎‎0.5L/min, and ‎the highest amount of ‎heat energy was 550W/m². ‎Wind speed showed an important impact on the produced temperature; therefore, various comparative experiments were carried out in the same climate condition; ‎the experiment with the insulating function ‎presented the least heat loss, and it takes a higher edge of 11% in terms of efficiency. ‎In addition, the water temperature rose to 120°C where steam was generated at a zero flow rate, while the oil ‎reached 194ºC. In addition, a mathematical model was also implemented to theoretically study energy balance; with little expected discrepancy, its predictions and the experimental results agreed. In conclusion, the results presented reasonable markers of interest despite the poor environmental conditions during the experiments.‎

Perspective of staged hydrogen economy in Japan: A case study based on the data-driven method

Green hydrogen is an important energy source for replacing fossil fuels for a cleaner transition. While small-scale applications of green hydrogen have proven successful, large-scale nationwide adoption is essential. However, such a change cannot be accomplished overnight. Therefore, this study proposes a staged hydrogen economy scenario for Japan based on the existing energy sources. In this scenario, thermal power generation will be gradually phased out, and the energy shortfall will be compensated by increasing the penetration of renewables and energy storage. Hydrogen and ammonia serve as short- and long-term energy storage solutions, respectively. A data-driven model combining heuristics and optimization methods was designed to address optimal planning and sizing problems. The results show that it is feasible to achieve a 20 % reduction in thermal power by replacing it with renewable energy and hydrogen or ammonia. The lowest levelized cost of electricity (LCOE) in Tokyo (Kanto district) is 0.072 USD·kWh−1, which is comparable to the baseline scenario (using fossil fuels). Hydrogen and ammonia are effective in reducing the LCOE and addressing the mismatch between supply and demand. A higher reduction in thermal power requires further technological and policy support. According to the sensitivity analysis, hydrogen prices and carbon taxes have a high potential to advance the hydrogen economy scenario in the future.