Publications

In this study the annual electricity consumption of nine real houses from different cities in Türkiye was recorded on a monthly basis. The feasibility of meeting the electrical energy needs of houses with hydrogen and supplying the energy required for hydrogen production using solar panels is examined. The annual electricity consumption of the houses was normalized based on house size. The solar panel area for hydrogen production needed for these houses was defined. Additionally it was calculated that the average volumetric amount of hydrogen produced per hour during peak sun hours in the investigated cities was 1 m3/h. This approach reduced the solar panel area for hydrogen production by a factor of 1.7.

As the consequences of global warming become more severe it is more crucial than ever to capitalize on all locally accessible potential renewable energy sources and produce sufficient useable energy outputs to meet community demands while causing the least damage to the ecosystem. Therefore this paper focuses on a unique parabolic trough collector solar systempowered electro-biomembrane unit that combines a heat and power system with fresh water electricity and hydrogen (H2) production. The proposed integrated system contains the following subsystems: a combining parabolic trough collector solar system an organic Rankine cycle a steam Rankine cycle a multi-stage flash desalination system and an electro-biomembrane H2 and freshwater production system. A thorough analysis and parametric research are performed on the multigeneration system to determine how important characteristics affect system performance and evaluate the energy and exergy efficiency and exergy destruction levels for particular system elements. The study results show that solar irradiation is the most critical parameter for improving system performance. The highest freshwater production of 1303333.3 L/day is observed at the solar irradiation of 935768 kWh/day. Furthermore the combined output of three electricity production technologies exceeds 2000000 kWh/day highlighting the ability of the system to harness solar thermal energy effectively. The findings indicate that using solar power and biomass as renewable energy sources the proposed integrated system provided 328.56 kg of biohydrogen per day. Overall the energy and exergy efficiencies of the integrated system are obtained at 34.3 and 29.5 % respectively.

Hydrogen production via water splitting is a crucial strategy for addressing the global energy crisis and promoting sustainable energy solutions. This review systematically examines water-splitting mechanisms with a focus on photocatalytic and electrochemical methods. It provides in-depth discussions on charge transfer reaction kinetics and key processes such as the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Various electrode synthesis techniques including hydrothermal methods chemical vapor deposition (CVD) pulsed laser deposition (PLD) and radio frequency sputtering (RF) are reviewed for their advantages and limitations. The role of carbon-based materials such as graphene biochar and graphitic carbon nitride (g-C3N4) in photocatalytic and photoelectrochemical (PEC) water splitting is also highlighted. Their exceptional conductivity tunable band structures and surface functionalities contribute to efficient charge separation and enhanced light absorption. Further advancements in heterojunctions doped systems and hybrid composites are explored for their ability to improve photocatalytic and PEC performance by minimizing charge recombination optimizing electronic structures and increasing active sites for hydrogen and oxygen evolution reactions. Key challenges including material stability cost scalability and solar spectrum utilization are critically analyzed along with emerging strategies such as novel synthesis approaches and sustainable material development. By integrating water splitting mechanisms electrode synthesis techniques and advancements in carbon-based materials this review provides a comprehensive perspective on sustainable hydrogen production bridging previously isolated research domains.

This article discusses the planning sizing and placement of a vehicle refueling station supplied by renewable energy systems including photovoltaic wind biomass units and an integrated battery system within a smart distribution network. The proposed station comprises facilities for hydrogen fueling and electric vehicle charging stations structured as a bi-level optimization approach. The upper-level model focuses on the planning phase of the refueling station. Its objective is to minimize annual costs associated with construction maintenance and operation. Key constraints involve operational planning for renewable sources battery systems and vehicle refueling stations while accounting for reactive power management. In contrast the lower-level formulation deals with the eco-scheduling of smart distribution grid. Its goal is to minimize the sum of annual energy losses and operation costs within the grid governed by linearized optimal power flow model. To account for uncertainties in demand energy prices renewable generation output and refueling station performance a stochastic optimization framework is employed. The solution is derived using Benders decomposition algorithm to achieve optimal results. The primary innovation highlighted in this paper includes integrating renewable resources and battery systems to power the refueling station leveraging reactive power control for improved station performance and addressing both operational and economic objectives in the distribution system. Numerical results underscore the advantages of this strategy. Constructing a refueling station without battery and renewable units leads to significant drawbacks an increase in network operation cost by 144.6% and grid energy loss by 167.6%. Voltage levels drop below 0.9 per-unit and distribution lines experience severe loading of up to 34.7%. In contrast the proposed plan enhances network economics by 51.3%-74.5% and operational conditions by 17.7%-148.1% effectively showcasing the benefits of incorporating sustainable technologies and advanced planning methods into refueling station development.

Decreasing prices of renewable energy sources (RES) like wind and solar in recent years have led to numerous studies on the optimal design of RES for hydrogen production in an off-grid system. RES are intermittent and vary from year to year. Yet most of the studies still consider only a random single weather year for system design often ignoring the impact of input weather data on system design and its performance. This study evaluates for a gaseous hydrogen system the impact of input weather data on optimal system design system reliability and system costs. Random single-year averaged and multiple years of weather data from 1994 to 2021 are considered. Further multiple years of weather data are considered using a novel method of near-optimal solutions and a maximum of near-optimal solutions. The results show that using the maximum of near-optimal solutions method improves system reliability by as much as 96 % when used in other weather years. The system costs are reduced to 0.1 €/kgH2 in other weather years at the expense of an oversized system design. Meanwhile a wind-to-hydrogen system (WHS) designed using randomly selected single-year weather data results in a significantly undersized system with lower reliability (3.5 %) and higher cost variability (up to 4.7 €/kgH2) in other weather years. On the other hand averaging the weather data smoothens the weather fluctuations and always results in a WHS design with lower reliability and higher cost variability than a WHS designed using multi-year weather data values. The results reveal that the size of input weather dataset significantly impacts the system design and its performance. The maximum of near-optimal solutions method proposed in this study provided significantly lower computational time with improved system performance (reliability and cost variability) in comparison to solving the WHS using multiple years of weather data outright.

This paper presents a comprehensive SWOT (strengths weaknesses opportunities and threats) analysis of utilizing hydrogen as a renewable fuel of non-biological origin (RFNBO) in Poland’s energy transition. Given Poland’s reliance on fossil fuels its deep decarbonization poses socio-economic and infrastructural challenges. This study examines the strengths weaknesses opportunities and threats associated with integrating hydrogen as an RFNBO fuel into Poland’s energy mix focusing on economic regulatory technological and social factors. The strengths identified include potential energy independence from fossil fuels increased investment and hydrogen’s applicability in hard-to-abate sectors. Weaknesses involve a low share of renewable hydrogen in the energy mix and the need for infrastructure development. Opportunities arise from European Union policies technological advancements and global trends favoring renewable hydrogen adoption. Threats encompass high production costs regulatory uncertainties and competition from other energy carriers. The analysis concludes that while hydrogen as an RFNBO fuel offers potential for decarbonizing Poland’s energy mix realizing this potential requires large-scale investments a supportive regulatory framework and technological innovation.

Transitioning from fossil fuels to renewable energies is imperative for Germany to reduce CO2 emissions and achieve greenhouse gas neutrality by 2045. Green hydrogen holds great potential to contribute to this energy transition by enabling the storage of surplus renewable energy. However Germany's green hydrogen production industry is still in its infancy with only a few green hydrogen plants existing. Studies examining the public's acceptance of green hydrogen production are scarce in this context. Still high societal acceptance can contribute to the future expansion of green hydrogen production in Germany in terms of speed and volume. Therefore our study aims to identify significant factors influencing the German population's acceptance of green hydrogen production within various acceptance groups with differing preferences for future green hydrogen production systems. We conducted an online survey (n=1203) in Germany in 2022/2023 incorporating a choice experiment. Through subsequent latent class analysis four acceptance groups with distinct preferences regarding local green hydrogen production were identified: Unconvinced citizens Security-conscious citizens Regional electricity consumers and Financial beneficiaries. A discriminant analysis identified 9 out of 11 factors as significant for distinguishing between these acceptance groups regarding their preferences for local green hydrogen production: trust in plant safety trust in project managers risk/benefit perception environmental self-identity negative attitude towards renewable energies positive attitude towards renewable energies emotions age and gender. However no significant effects were observed for experience with green hydrogen and distance to the place of residence. Based on our results it is recommended that required renewable energy for green hydrogen production should be produced as close to the green hydrogen plants as possible. It must be ensured and communicated to the public that the (planned) green hydrogen plants meet high safety standards and pose a very low risk of fire or explosion. The neighbouring population should also benefit through annual heating cost savings and financial participation. Implementing these measures can increase acceptance of local green hydrogen production facilitating the transition towards a more sustainable energy future in Germany and beyond.

A composite hydrogen storage vessel (CHSV) is one key component of the hydrogen fuel cell vehicle which always suffers random vibration during transportation resulting in fatigue failure and a reduction in service life. In this paper firstly the free and constrained modes of CHSV are experimentally studied and numerically simulated. Subsequently the random vibration simulation of CHSV is carried out to predict the stress distribution while Steinberg’s method and Dirlik’s method are used to predict the fatigue life of CHSV based on the results of stress distribution. In the end the optimization of ply parameters of the composite winding layer was conducted to improve the stress distribution and fatigue life of CHSV. The results show that the vibration pattern and frequency of the free and constrained modes of CHSV obtained from the experiment tests and the numerical predictions show a good agreement. The maximum difference in the value of the vibration frequency of the free and constrained modes of CHSV from the FEA and experiment tests are respectively 8.9% and 8.0% verifying the accuracy of the finite element model of CHSV. There is no obvious difference between the fatigue life of the winding layer and the inner liner calculated by Steinberg’s method and Dirlik’s method indicating the accuracy of FEA of fatigue life in the software Fe-safe. Without the optimization the maximum stresses of the winding layer and the inner liner are found to be near the head section by 469.4 MPa and 173.0 MPa respectively and the numbers of life cycles of the winding layer and the inner liner obtained based on the Dirlik’s method are around 1.66 × 106 and 3.06 × 106 respectively. Through the optimization of ply parameters of the composite winding layer the maximum stresses of the winding layer and the inner liner are reduced by 66% and 85% respectively while the numbers of life cycles of the winding layer and the inner liner both are increased to 1 × 107 (high cycle fatigue life standard). The results of the study provide theoretical guidance for the design and optimization of CHSV under random vibration.

Geological storage is an integral element of the green energy transition. Geological formations such as aquifers depleted reservoirs and hard rock caverns are used mainly for the storage of hydrocarbons carbon dioxide and increasingly hydrogen. However potential adverse effects such as ground movements leakage seismic activity and environmental pollution are observed. Existing research focuses on monitoring subsurface elements of the storage while on the surface it is limited to ground movement observations. The review was carried out based on 191 research contributions related to geological storage. It emphasizes the importance of monitoring underground gas storage (UGS) sites and their surroundings to ensure sustainable and safe operation. It details surface monitoring methods distinguishing geodetic surveys and remote sensing techniques. Remote sensing including active methods such as InSAR and LiDAR and passive methods of multispectral and hyperspectral imaging provide valuable spatiotemporal information on UGS sites on a large scale. The review covers modelling and prediction methods used to analyze the environmental impacts of UGS with data-driven models employing geostatistical tools and machine learning algorithms. The limited number of contributions treating geological storage sites holistically opens perspectives for the development of complex approaches capable of monitoring and modelling its environmental impacts.

The widespread penetration of hydrogen in mainstream energy systems requires hydrogen production processes to be economically competent and environmentally efficient. Hydrogen if produced efficiently can play a pivotal role in decarbonizing the global energy systems. Therefore this study develops a framework which evaluates hydrogen production processes and quantifies deficiencies for improvement. The framework integrates slack-based data envelopment analysis (DEA) with fuzzy analytical hierarchy process (FAHP) and fuzzy technique for order of preference by similarity to ideal solution (FTOPSIS). The proposed framework is applied to prioritize the most efficient and sustainable hydrogen production in Pakistan. Eleven hydrogen production alternatives were analyzed under five criteria including capital cost feedstock cost O&M cost hydrogen production and CO2 emission. FAHP obtained the initial weights of criteria while FTOPSIS determined the ultimate weights of criteria for each alternative. Finally slack-based DEA computed the efficiency of alternatives. Among the 11 three alternatives (wind electrolysis PV electrolysis and biomass gasification) were found to be fully efficient and therefore can be considered as sustainable options for hydrogen production in Pakistan. The rest of the eight alternatives achieved poor efficiency scores and thus are not recommended.