Search Results (497)

This study proposes an integrated framework for the optimal sizing of off-grid hybrid energy systems, combining photovoltaic panels, wind turbines, battery storage, a diesel generator, and an inverter. The methodology uniquely integrates long-term meteorological forecasting through a hybrid approach based on the Discrete Wavelet Transform and Long Short-Term Memory networks, together with metaheuristic optimization techniques (Particle Swarm Optimization and Genetic Algorithm), to minimize the system’s total annual cost. A case study was conducted in Guanambi, Brazil, using ten years (2012–2021) of hourly data on wind speed, solar irradiance, and ambient temperature. Forecasting results show that the hybrid Discrete Wavelet Transform–Long Short-Term Memory model outperforms the conventional Long Short-Term Memory approach, reducing error metrics and improving predictive accuracy. In the optimization stage, Particle Swarm Optimization consistently achieved lower costs and more stable convergence compared to the Genetic Algorithm. The optimal configuration comprised 450 photovoltaic panels, 10 wind turbines, 66 lithium iron phosphate battery, and 1 diesel generator, yielding a total annual cost of $105,381.17, a cost of energy of $0.1243/kWh, and minimal diesel dependence ($8825.89 annually). The proposed framework demonstrates robustness, economic viability, and applicability for providing sustainable and reliable electricity in isolated regions with high renewable energy potential. Full article

Unplanned islanding and off-grid issues of photovoltaic (PV) power stations caused by tie-line faults have seriously undermined the power supply reliability and operational stability of PV plants. Furthermore, it takes a relatively long time to restore normal operation after an off-grid event, leading to substantial power losses. To address this problem, this paper proposes a tie-line fault ride-through control strategy based on the coordinated control of on-site energy storage units. After a fault on the tie-line occurs, the control mode of PV inverters is switched to achieve source–load balance, and the control mode of energy storage inverters is switched to VF control mode, which supports the stability of voltage and frequency in the islanded system. Subsequently, the strategy coordinates with the tie-line recloser device to perform synchronous checking and grid reconnection. Simulation results show that, for transient tie-line faults, the proposed method can achieve stable control of the islanded system and grid reconnection within 2 s after a fault on the tie-line occurs. It successfully realizes fault ride-through within the operation time limit of anti-islanding protection, effectively preventing the PV plant from disconnecting from the grid. Finally, a connection scheme for the control strategy of a typical PV plant is presented, providing technical reference for on-site engineering. Full article

A novel methodology for hybrid energy management in aquaculture is introduced, aimed at enhancing self-sufficiency and optimizing grid-related cash flows. Wind and solar energy generation are modeled using calibrated turbine performance curves and PVGIS data, respectively, with a photovoltaic capacity of 120 kWp. The system also incorporates a 250 kW small hydroelectric plant and a wood drying kiln that utilizes surplus wind energy. This study conducts a comparative analysis between HY4RES, a research-oriented simulation model, and HOMER Pro, a commercially available optimization tool, across multiple hybrid energy scenarios at two aquaculture sites. For grid-connected configurations at the Primary site (base case, Scenarios 1, 2, and 6), both models demonstrate strong concordance in terms of energy balance and overall performance. In Scenario 1, a peak power demand exceeding 1000 kW is observed in both models, attributed to the biomass kiln load. Scenario 2 reveals a 3.1% improvement in self-sufficiency with the integration of photovoltaic generation, as reported by HY4RES. In the off-grid Scenario 3, HY4RES supplies an additional 96,634 kWh of annual load compared to HOMER Pro. However, HOMER Pro indicates a 3.6% higher electricity deficit, primarily due to battery energy storage system (BESS) losses. Scenario 4 yields comparable generation outputs, with HY4RES enabling 6% more wood-drying capacity through the inclusion of photovoltaic energy. Scenario 5, which features a large-scale BESS, highlights a 4.7% unmet demand in HY4RES, whereas HOMER Pro successfully meets the entire load. In Scenario 6, both models exhibit similar load profiles; however, HY4RES reports a self-sufficiency rate that is 1.3% lower than in Scenario 1. At the Secondary site, financial outcomes are closely aligned. For instance, in the base case, HY4RES projects a cash flow of 54,154 EUR, while HOMER Pro estimates 55,532 EUR. Scenario 1 presents nearly identical financial results, and Scenario 2 underscores HOMER Pro’s superior BESS modeling capabilities during periods of reduced hydroelectric output. In conclusion, HY4RES demonstrates robust performance across all scenarios. When provided with harmonized input parameters, its simulation results are consistent with those of HOMER Pro, thereby validating its reliability for hybrid energy management in aquaculture applications. Full article

In this paper, a method for finding the optimal size of an off-grid photovoltaic (PV) system regarding the Loss of Load Probability (LOLP) value is proposed. The proposed method is applied to an off-grid PV system in a scenario where an electricity supply needs to be provided during three summer months. According to the simulation results, 11 PV modules and 11 batteries are required with 0% LOLP. An increase in LOLP to 1% results in 10 PV modules and 7 batteries, and a 24.9% cost reduction. With 5% LOLP, the cost reduction is 39.3%, and with 10% LOLP, it is 49.5%. The use of less expensive batteries also contributes to cost reduction. With the modification of electricity consumption, one combination can be suitable for 4% lower LOLP, and the cost can be reduced to up to 7%. It can be concluded that the required increase in LOLP value leads to a decrease in the number of required PV modules and batteries and to the use of less expensive battery technologies, which then leads to cost reduction. Additionally, with the modification of electricity consumption, the amount of power deficit can be reduced, which makes one combination suitable for lower LOLP and also leads to a further system cost decrease. Lower system costs can encourage more people to invest in an off-grid PV system in locations with occasional consumption or consumption over only a few months. The cost reduction strongly depends on how willing users are to not have all their electricity demands met. Full article

Agrivoltaics (APV) mitigates land-use competition between photovoltaic installations and agricultural activities, thereby supporting multifaceted policy objectives in energy transition and sustainability. The availability of organic residuals from agrifood practices may also open the way to their energy valorization. This paper examines a small-scale farm in the Basilicata Region, southern Italy, to investigate the potential installation of an APV plant or a combined APV and bioenergy system to meet the electrical needs of the existing processing machinery. A dynamic numerical analysis is performed over an annual cycle to properly size the storage system under three distinct APV configurations. The panel shadowing effects on the underlying crops are quantified by evaluating the reduction in incident solar irradiance during daylight and the consequent agricultural yield differentials over the life period of each crop. The integration of APV and a biomass-powered cogenerator is then considered to explore the possible off-grid farm operation. In the sole APV case, the single-axis tracking configuration achieves the highest performance, with 45.83% self-consumption, a land equivalent ratio (LER) of 1.7, and a payback period of 2.77 years. For APV and bioenergy, integration with a 20 kW cogeneration unit achieves over 99% grid independence by utilizing a 97.57 kWh storage system. The CO₂ emission reduction is 49.6% for APV alone and 100% with biomass integration. Full article

Sudan’s rural regions face acute challenges in energy access, exacerbated by ongoing conflict that has destroyed major power infrastructure and crippled conventional electricity generation. This study investigates the technical and economic feasibility of photovoltaic (PV) solar systems as a sustainable alternative for powering off-grid rural communities. Using MATLAB simulations (Version 24b), Global Solar Atlas data, and HOMER software (Version 4.11) for hybrid system optimization, a case study of a village in Shariq al-Nil, Khartoum, demonstrates the viability of solar energy to meet residential, medical, and agricultural needs. Beyond technical analysis, this paper highlights the transformative role of solar energy in post-conflict reconstruction, with potential applications in powering irrigation systems and supporting agricultural livelihoods. It also emphasizes the importance of integrating community-centered policy frameworks to ensure equitable access, long-term adoption, and sustainable development outcomes. The findings advocate for policies that support renewable energy investment as a cornerstone of rebuilding efforts in Sudan and similar contexts affected by conflict and infrastructure collapse. Full article

Remote First Nations communities in Australia experience ongoing energy insecurity due to geographic isolation, reliance on diesel, and uneven consumer protections relative to grid-connected households. This paper analyses evidence on electricity access, infrastructure and practical experience along with initiatives for improving existing infrastructure; highlights government policies, funding frameworks and regulation; demonstrates the benefits of community-led projects; provides geographic and demographic insights; and relevels key challenges along with pathways for effective solutions. Drawing on existing program experience, case studies and recent reforms (including First Nations–focused strategies and off-grid consumer-protection initiatives), this paper demonstrates that community energy systems featuring solar-battery systems can significantly improve reliability and affordability by reducing reliance on diesel generators and delivering tangible household benefits. The analyses reveal that there is an ongoing gap in protecting off-grid consumers. Hence, this work proposes a practical agenda to improve electricity supply systems for First Nations community energy systems through advanced community microgrids (including long-duration storage), intelligent energy management and monitoring systems, rights-aligned consumer mechanisms for customers with prepaid metering systems, fit-for-purpose regulation, innovative blended finance (e.g., Energy-as-a-Service and impact investment) and on-country workforce development. Overall, this paper contributes to a perspective for an integrated framework that couples technical performance with equity, cultural authority and energy sovereignty, offering a replicable pathway for reliable, affordable and clean electricity for remote First Nations communities. Full article

Switch-point heating systems are essential for railway reliability and safety in winter, but present logistical and economic challenges in remote regions. This study presents a novel application of a hydrogen-enabled microgrid as an off-grid energy solution for powering a switch-point heating system at a rural Austrian railway station, offering an alternative to conventional grid-based electricity with a specific focus on enhancing the share of renewable energy sources. The proposed system integrates photovoltaics (PV), optional wind energy, and hydrogen storage to address the seasonal mismatch between a high energy supply in the summer and peak winter demand. Three energy supply scenarios are analysed and compared based on local conditions, technical simplicity, and economic viability. Energy flow modelling based on site-specific climate and operational data is used to determine hydrogen production rates, storage capacity requirements and system sizing. A comprehensive cost analysis of all major subsystems is conducted to assess economic viability. The study demonstrates that hydrogen is a highly effective solution for seasonal energy storage, with a PV-only configuration emerging as the most suitable option under current site conditions. Thus, it offers a replicable framework for decarbonising critical stationary railway infrastructure. Full article

This study presents a novel multi-objective optimization (MOO) model for the design of an off-grid hybrid renewable energy system (HRES) to support sustainable agriculture and rural development in Sub-Saharan Africa (SSA). Based upon a case study selected in Linia (Chad), three system architectures are compared under different levels of the reliability requirements (LPSP = 1%, 5%, and 10%). A Multi-Objective Particle Swarm Optimization (MOPSO) algorithm is applied to optimize the Levelized Cost of Energy (LCOE), CO₂ emissions mitigation, and social impact, referring to the Human Development Index (HDI) enhancement and the job creation (JC) opportunity, using the MATLAB R2024b environment. The calculation results show that among the three configuration schemes, the PV–Wind–Battery configuration obtains the optimal techno–economic–environmental coordination, with the lowest LCOE (0.0948 $/kWh) and the largest CO₂ emission reduction (9.58 × 10⁸ kg), and the Wind–Battery system gets the most social benefit. The method developed provides users with a decision-support method for renewable energy systems (RES) integration into rural agricultural settings, taking into consideration financial cost, environmental sustainability, and community development. This information is important for policymakers and practitioners advocating for decentralized, socially inclusive clean energy access initiatives in underserved regions. Full article

Electricity access deficits remain acute in Sub-Saharan Africa (SSA), where more than 600 million people lack reliable supply. Green hydrogen, produced through renewable-powered electrolysis, is increasingly recognized as a transformative energy carrier for decentralized systems due to its capacity for long-duration storage, sector coupling, and near-zero carbon emissions. This review adheres strictly to the PRISMA 2020 methodology, examining 190 records and synthesizing 80 peer-reviewed articles and industry reports released from 2010 to 2025. The review covers hydrogen production processes, hybrid renewable integration, techno-economic analysis, environmental compromises, global feasibility, and enabling policy incentives. The findings show that Alkaline (AEL) and PEM electrolyzers are immediately suitable for off-grid scenarios, whereas Solid Oxide (SOEC) and Anion Exchange Membrane (AEM) electrolyzers present high potential for future deployment. For Sub-Saharan Africa (SSA), the levelized costs of hydrogen (LCOH) are in the range of EUR5.0–7.7/kg. Nonetheless, estimates from the learning curve indicate that these costs could fall to between EUR1.0 and EUR1.5 per kg by 2050, assuming there is (i) continued public support for the technology innovation, (ii) appropriate, flexible, and predictable regulation, (iii) increased demand for hydrogen, and (iv) a stable and long-term policy framework. Environmental life-cycle assessments indicate that emissions are nearly zero, but they also highlight serious concerns regarding freshwater usage, land occupation, and dependence on platinum group metals. Namibia, South Africa, and Kenya exhibit considerable promise in the early stages of development, while Niger demonstrates the feasibility of deploying modular, community-scale systems in challenging conditions. The study concludes that green hydrogen cannot be treated as an integrated solution but needs to be regarded as part of blended off-grid systems. To improve its role, targeted material innovation, blended finance, and policies bridging export-oriented applications to community-scale access must be established. It will then be feasible to ensure that hydrogen contributes meaningfully to the attainment of Sustainable Development Goal 7 in SSA. Full article

The increasing interest in off-grid green hydrogen production has elevated the importance of reliable techno-economic assessment (TEA) tools to support investment and planning decisions. However, limited operational data and inconsistent modeling approaches across existing tools introduce significant uncertainty in cost estimations. This study presents a comprehensive review and comparative analysis of seven TEA tools—ranging from simplified calculators to advanced hourly based simulation platforms—used to estimate the Levelized Cost of Hydrogen (LCOH) in off-grid Hydrogen Production Plants (HPPs). A standardized simulation framework was developed to input consistent technical, economic, and financial parameters across all tools, allowing for a horizontal comparison. Results revealed a substantial spread in LCOH values, from EUR 5.86/kg to EUR 8.71/kg, representing a 49% variation. This discrepancy is attributed to differences in modeling depth, treatment of critical parameters (e.g., electrolyzer efficiency, capacity factor, storage, and inflation), and the tools’ temporal resolution. Tools that included higher input granularity, hourly data, and broader system components tended to produce more conservative (higher) LCOH values, highlighting the cost impact of increased modeling realism. Additionally, the total project cost—more than hydrogen output—was identified as the key driver of LCOH variability across tools. This study provides the first multi-tool horizontal testing protocol, a methodological benchmark for evaluating TEA tools and underscores the need for harmonized input structures and transparent modeling assumptions. These findings support the development of more consistent and reliable economic evaluations for off-grid green hydrogen projects, especially as the sector moves toward commercial scale-up and policy integration. Full article

Achieving net-zero emissions in arid and high-solar-yield regions demands innovative, cost-effective, and scalable energy technologies. This study conducts a comprehensive techno-economic analysis and assessment of a novel hybrid photovoltaic–thermal solar collector (U.S. Patent No. 11,431,289) that integrates a reverse flat plate collector and mini-concentrating solar thermal elements. The system was tested in Qatar and Germany and simulated via a System Advising Model tool with typical meteorological year data. The system demonstrated a combined efficiency exceeding 90%, delivering both electricity and thermal energy at temperatures up to 170 °C and pressures up to 10 bars. Compared to conventional photovoltaic–thermal systems capped below 80 °C, the system achieves a heat-to-power ratio of 6:1, offering an exceptional exergy performance and broader industrial applications. A comparative financial analysis of 120 MW utility-scale configurations shows that the PVT + ORC option yields a Levelized Cost of Energy of $44/MWh, significantly outperforming PV + CSP ($82.8/MWh) and PV + BESS ($132.3/MWh). In addition, the capital expenditure is reduced by over 50%, and the system requires 40–60% less land, offering a transformative solution for off-grid data centers, water desalination (producing up to 300,000 m³/day using MED), district cooling, and industrial process heat. The energy payback time is shortened to less than 4.5 years, with lifecycle CO₂ savings of up to 1.8 tons/MWh. Additionally, the integration with Organic Rankine Cycle (ORC) systems ensures 24/7 dispatchable power without reliance on batteries or molten salt. Positioned as a next-generation solar platform, the Hassabou system presents a climate-resilient, modular, and economical alternative to current hybrid solar technologies. This work advances the deployment readiness of integrated solar-thermal technologies aligned with national decarbonization strategies across MENA and Sub-Saharan Africa, addressing urgent needs for energy security, water access, and industrial decarbonization. Full article

Access to renewable energy is vital for rural development and climate change mitigation. The intermittency of renewable sources necessitates efficient energy storage, especially in off-grid applications. This study evaluates the technical, economic, and environmental performance of an off-grid hybrid system for the rural settlement of Soma, Turkey. Using HOMER Pro 3.14.2 software, a system consisting of solar, wind, battery, and hydrogen components was modeled under four scenarios with Cyclic Charging (CC) and Load Following (LF) control strategies for optimization. Life cycle assessment (LCA) and hydrogen leakage impacts were calculated separately through MATLAB R2019b analysis in accordance with ISO 14040 and ISO 14044 standards. Scenario 1 (PV + wind + battery + H₂) offered the most balanced solution with a net present cost (NPC) of USD 297,419, with a cost of electricity (COE) of USD 0.340/kWh. Scenario 2 without batteries increased hydrogen consumption despite a similar COE. Scenario 3 with wind only achieved the lowest hydrogen consumption and the highest efficiency. In Scenario 4, hydrogen consumption decreased with battery reintegration, but COE increased. Specific CO₂ emissions ranged between 36–45 gCO₂-eq/kWh across scenarios. Results indicate that the control strategy and component selection strongly influence performance and that hydrogen-based hybrid systems offer a sustainable solution in rural areas. Full article

Human-powered electricity generation (HPEG) systems offer promising sustainable energy solutions, yet existing deterministic models fail to capture the inherent variability in human biomechanical performance. This study develops a comprehensive stochastic framework integrating advanced Monte Carlo uncertainty quantification with multi-component fatigue modeling and Pareto optimization. The framework incorporates physiological parameter vectors, kinematic variables, and environmental factors through multivariate distributions, addressing the complex stochastic nature of human power generation. A novel multi-component efficiency function integrates biomechanical, coordination, fatigue, thermal, and adaptation effects, while advanced fatigue dynamics distinguish between peripheral muscular, central neural, and substrate depletion mechanisms. Experimental validation (623 trials, 7 participants) demonstrates RMSE of 3.52 W and CCC of 0.996. Monte Carlo analysis reveals mean power output of 97.6 ± 37.4 W (95% CI: 48.4–174.9 W) with substantial inter-participant variability (CV = 37.6%). Pareto optimization identifies 19 non-dominated solutions across force-cadence space, with maximum power configuration achieving 175.5 W at 332.7 N and 110.4 rpm. This paradigm shift provides essential foundations for next-generation HPEG implementations across emergency response, off-grid communities, and sustainable infrastructure applications. The framework thus delivers dual contributions: advancing stochastic uncertainty quantification methodologies for complex biomechanical systems while enabling resilient decentralized energy solutions critical for sustainable development and climate adaptation strategies. Full article

This study presents the simulation of a standalone photovoltaic (PV) water pumping system that is made for use in rural areas and off-grid applications. The system contains a 174 W PV panel, a DC-DC boost converter, a DC motor, and a centrifugal pump. To optimize energy extraction, three maximum power point techniques (MPPT), Perturb and Observe (P&O), incremental conductance (INC), and a Hybrid P&O–INC algorithm, were implemented and evaluated. Unlike most prior studies focusing on large-scale systems, this work targets low-power configurations with load dynamics specific to motor–pump assemblies. The hybrid algorithm is finely tuned using conservative step sizes and adaptive switching thresholds. Simulation results under varying irradiance levels show that the hybrid MPPT achieves the best trade-off, combining high tracking efficiency with reduced power ripple, particularly under challenging low-irradiance conditions. Moreover, the approach offers a favorable balance between performance and implementation cost, positioning it as a viable and scalable solution for sustainable water supply in remote communities. Full article