Poland

The paper presents the possibilities of low-emission-powered vehicles based mainly on compressed hydrogen. It shows currently used forms of powering vehicles based on their genesis process of obtention and popularity. They are also compared to each other presenting the advantages and disadvantages of a given solution. The share of electricity in transport its forecasts for the future and the possibilities of combination with conventional energy sources are also described. Based on current technological capabilities hydrogen plays a crucial role as presented in the above work constituting a fundamental basis for future transport solutions.

A huge amount of organic waste is generated annually around the globe. The main sources of solid and liquid organic waste are municipalities and canning and food industries. Most of it is disposed of in an environmentally unfriendly way since none of the modern recycling technologies can cope with such immense volumes of waste. Microbiological and biotechnological approaches are extremely promising for solving this environmental problem. Moreover organic waste can serve as the substrate to obtain alternative energy such as biohydrogen (H2 ) and biomethane (CH4 ). This work aimed to design and test new technology for the degradation of food waste coupled with biohydrogen and biomethane production as well as liquid organic leachate purification. The effective treatment of waste was achieved due to the application of the specific granular microbial preparation. Microbiological and physicochemical methods were used to measure the fermentation parameters. As a result a four-module direct flow installation efficiently couples spatial succession of anaerobic and aerobic bacteria with other micro- and macroorganisms to simultaneously recycle organic waste remediate the resulting leachate and generate biogas.

This article presents a novel approach to the analysis of heat release in a hydrogen-fueled internal combustion spark-ignition engine with exhaust gas recirculation (EGR). It also discusses aspects of thermodynamic analysis common to modeling and empirical analysis. This new approach concerns a novel method of calculating the specific heat ratio (cp/cv) and takes into account the reduction in the number of moles during combustion which is characteristic of hydrogen combustion. This reduction in the number of moles was designated as a molar contraction. This is particularly crucial when calculating the average temperature during combustion. Subsequently the outcomes of experimental tests including the heat-release rate the initial combustion phase (denoted CA0- 10) and the main combustion phase (CA10-90) are presented. Furthermore the impact of exhaust gas recirculation on the combustion process in the engine is also discussed. The efficacy of the proposed measures was validated by analyzing the heat-release rate and calculating the mean combustion temperature in the engine. The application of EGR in the range 0-40% resulted in a notable prolongation of both the initial and main combustion phases which consequently influenced the mean combustion temperature.

The large-scale deployment of technologies that enable energy from renewables is essential for a successful transition to a carbon-neutral future. While photovoltaic panels are one of the main technologies commonly used for harvesting energy from the Sun storage of renewable solar energy still presents some challenges and often requires integration with additional devices. It is believed that hydrogen – being a perfect energy carrier – can become one of the broadly utilised storage alternatives that would effectively mitigate the energy supply and demand issues associated with the intermittent nature of renewable energy sources. Current pathways in the development of green technologies indicate the need for more sustainable material utilisation and more efficient device operation. To address this requirement integration of various technologies for renewable energy harvesting conversion and storage in a single device appears as an advantageous option. From the hydrogen economy perspective systems driven by green solar electricity that allow for (photo)electrochemical water splitting would generate hydrogen with the minimal CO2 footprint. If at the same time one of the device electrodes could store the generated gas and release it on demand the utilisation of critical and often costly elements would be reduced with possible gain in more effective device operation. Although conceptually attractive this cross-disciplinary concept has not gained yet enough attention and only limited number of experimental setups have been designed tested and reported. This review presents the first exhaustive overview and critical examination of various laboratory-scale prototype setups that attempt to combine both the hydrogen production and storage processes in a single unit via integration of a metal hydride-based electrode into a photoelectrochemical cell. The architectures of presented configurations enables direct solar energy to hydrogen conversion and its subsequent storage in a single device which – in some cases – can also release the stored (hydrogen) energy on demand. In addition this work explores perspectives and challenges related with the potential upscaling of reviewed solar-to-hydrogen storage systems trying to map and indicate the main future directions of their technological development and optimization. Finally the review also combines information and expertise scattered among various research fields with the aim of stimulating much-needed exchange of knowledge to accelerate the progress in the development and deployment of optimum green hydrogen-based solutions.

Efforts to direct the economies of many countries towards low-carbon economies are being made in order to reduce their impact on global climate change. Within this process replacing fossil fuels with hydrogen will play an important role in the sectors where electrification is difficult or technically and economically ineffective. Hydrogen may also play a critical role in renewable energy storage processes. Thus the global hydrogen demand is expected to rise more than five times by 2050 while in the European Union a seven-fold rise in this field is expected. Apart from many technical and legislative barriers the environmental impact of hydrogen production is a key issue especially in the case of new and developing technologies. Focusing on the various pathways of hydrogen production the essential problem is to evaluate the related emissions through GHG accounting considering the life cycle of a plant in order to compare the technologies effectively. Anion exchange membrane (AEM) electrolysis is one of the newest technologies in this field with no LCA studies covering its full operation. Thus this study is focused on a calculation of the carbon footprint and economic indicators of a green hydrogen plant on the basis of a life cycle assessment including the concept of a solar-to-hydrogen plant with AEM electrolyzers operating under Polish climate conditions. The authors set the range of the GWP indicators as 2.73–4.34 kgCO2eq for a plant using AEM electrolysis which confirmed the relatively low emissivity of hydrogen from solar energy also in relation to this innovative technology. The economic profitability of the investment depends on external subsidies because as developing technology the AEM electrolysis of green hydrogen from photovoltaics is still uncompetitive in terms of its cost without this type of support.

The main results highlighted in this article underline the critical significance of hydrogen technologies in the move towards carbon neutrality. This research focuses on several key areas including the production storage safety and usage of hydrogen alongside innovative approaches for assessing hydrogen purity and production-related technologies. This study emphasizes the vital role of hydrogen storage technology for the future utilization of hydrogen as an energy carrier and the advancement of technologies that facilitate effective safe and cost-efficient hydrogen storage. Furthermore bibliometric analysis has been instrumental in identifying primary research fields such as hydrogen storage hydrogen production efficient electrocatalysts rotary engines utilizing hydrogen as fuel and underground hydrogen storage. Each domain is essential for realizing a sustainable hydrogen economy reflecting the significant research and development efforts in hydrogen technologies. Recent trends have shown an increased interest in underground hydrogen storage as a method to enhance energy security and assist in the transition towards sustainable energy systems. This research delves into the technical economic and environmental facets of employing geological formations for large-scale seasonal and long-term hydrogen storage. Ultimately the development of hydrogen technologies is deemed crucial for meeting sustainable development goals particularly in terms of addressing climate change and reducing greenhouse gas emissions. Hydrogen serves as an energy carrier that could substantially lessen reliance on fossil fuels while encouraging the adoption of renewable energy sources aiding in the decarbonization of transport industry and energy production sectors. This in turn supports worldwide efforts to curb global warming and achieve carbon neutrality.

The main purpose of this work is to investigate the influence of methane addition in methane-hydrogen-air mixture (φ = 0.8 – 1.6) on the critical conditions for transition to detonation in a 90-deg wedge corner. Similar to hydrogen-air mixtures investigated previously [1] methane-hydrogen-air mixtures results showed three ignition modes weak ignition followed by deflagration with ignition delay time higher than 1 μs strong ignition with instantaneous transition to detonation and third with deflagrative ignition and delayed transition to detonation. Methane addition caused an increase in the range of 3.25 – 5.03% in the critical shock wave velocity necessary for transition to detonation for all mixtures considered. For example in stoichiometric mixture with 5% methane in fuel (95% hydrogen in fuel) in air the transition to detonation velocity was approx. 752 m/s (an increase of 37 m/s from hydrogen-air) corresponding to M = 1.89 (an increase of 0.14 from hydrogen-air) and 75.7% (an increase of 4.7% from hydrogen-air) of speed of sound in products. Also similar to hydrogen-air mixture the transition to detonation velocity increased for leaner and richer mixture. Moreover it was observed that methane addition in general increased the pressure limit at the corner necessary for transition to detonation.

Building a hydrogen economy is perceived as a way to achieve the decarbonization goals set out in the Paris Agreement to limit global warming as well as to meet the goals resulting from the European Green Deal for the decarbonization of Europe. This article presents a literature review of various aspects of this economy. The full added value chain of hydrogen was analyzed from its production through to storage transport distribution and use in various economic sectors. The current state of knowledge about hydrogen is presented with particular emphasis on its features that may determine the positives and negatives of its development. It was noted that although hydrogen has been known for many years its production methods are mainly related to fossil fuels which result in greenhouse gas emissions. The area of interest of modern science is limited to green hydrogen produced as a result of electrolysis from electricity produced from renewable energy sources. The development of a clean hydrogen economy is limited by many factors the most important of which are the excessive costs of producing clean hydrogen. Research and development on all elements of the hydrogen production and use chain is necessary to contribute to increasing the scale of production and use of this raw material and thus reducing costs as a result of the efficiencies of scale and experience gained. The development of the hydrogen economy will be related to the development of the hydrogen trade and the centers of this trade will differ significantly from the current centers of energy carrier trade.

This research investigates the potential of using bedded salt formations for underground hydrogen storage. We present a novel artificial intelligence framework that employs spatial data analysis and multi-criteria decision-making to pinpoint the most appropriate sites for hydrogen storage in salt caverns. This methodology incorporates a comprehensive platform enhanced by a deep learning algorithm specifically a convolutional neural network (CNN) to generate suitability maps for rock salt deposits for hydrogen storage. The efficacy of the CNN algorithm was assessed using metrics such as Mean Absolute Error (MAE) Mean Squared Error (MSE) Root Mean Square Error (RMSE) and the Correlation Coefficient (R2 ) with comparisons made to a real-world dataset. The CNN model showed outstanding performance with an R2 of 0.96 MSE of 1.97 MAE of 1.003 and RMSE of 1.4. This novel approach leverages advanced deep learning techniques to offer a unique framework for assessing the viability of underground hydrogen storage. It presents a significant advancement in the field offering valuable insights for a wide range of stakeholders and facilitating the identification of ideal sites for hydrogen storage facilities thereby supporting informed decisionmaking and sustainable energy infrastructure development.

The desire to maintain CO2 concentrations in the global atmosphere implies the need to introduce ’new’ energy carriers for transport applications. Therefore the operational consumption of each such potential medium in the ’natural’ exploitation of vehicles must be assessed. A useful assessment method may be the vehicle’s energy footprint resulting from the theory of cumulative fuel consumption presented in the article. Using a (very modest) database of long-term use of hydrogen-powered cars the usefulness of this method was demonstrated. Knowing the energy footprint of vehicles of a given brand and type and the statistical characteristics of the footprint elements it is also possible to assess vehicle fleets in terms of energy demand. The database on the use of energy carriers such as hydrogen in the long-term operation of passenger vehicles is still relatively modest; however as it has been shown valuable data can be obtained to assess the energy demand of vehicles of a given brand and type. Access to a larger operational database will allow for wider use of the presented method.

Unmanned aerial vehicles (UAVs) have become an integral part of modern life serving both civilian and military applications across various sectors. However existing power supply systems such as batteries often fail to provide stable long-duration flights limiting their applications. Previous studies have primarily focused on battery-based power which offers limited flight endurance due to lower energy densities and higher system mass. Proton exchange membrane (PEM) fuel cells present a promising alternative providing high power and efficiency without noise vibrations or greenhouse gas emissions. Due to hydrogen’s high specific energy which is substantially higher than that of combustion engines and battery-based alternatives UAV operational time can be significantly extended. This paper investigates the potential of PEM fuel cells as an alternative power source for electric propulsion in UAVs. This study introduces an adaptive fully functioning PEM fuel cell model developed using a reduced-order modeling approach and optimized for UAV applications. This research demonstrates that PEM fuel cells can effectively double the flight endurance of UAVs compared to traditional battery systems achieving energy densities of around 1700 Wh/kg versus 150–250 Wh/kg for batteries. Despite a slight increase in system mass fuel cells enable significantly longer UAV operations. The scope of this study encompasses the comparison of battery-based and fuel cell-based propulsion systems in terms of power mass and flight endurance. This paper identifies the limitations and optimal applications for fuel cells providing strong evidence for their use in UAVs where extended flight time and efficiency are critical.

The paper discusses potential hazards at hydrogen refueling stations for transportation vehicles: cars and trucks. The main hazard analyzed here is an uncontrolled gas release due to a failure in one of the structures in the station: storage tanks of different pressure levels or a dispenser. This may lead to a hydrogen cloud occurring near the source of the release or at a given distance. The range of the cloud was analyzed in connection to the amount of the released gas and the wind velocity. The results of the calculations were compared for chosen structures in the station. Then potential fires and explosions were investigated. The hazard zones were calculated with respect to heat fluxes generated in the fires and the overpressure generated in explosions. The maximum ranges of these zones vary from about 14 to 30 m and from about 9 to 14 m for a fires and an explosions of hydrogen respectively. Finally human death probabilities are presented as functions of the distance from the sources of the uncontrolled hydrogen releases. These are shown for different amounts and pressures of the released gas. In addition the risk of human death is determined along with the area where it reaches the highest value in the whole station. The risk of human death in this area is 1.63 × 10−5 [1/year]. The area is approximately 8 square meters.

This study conducted a Life Cycle Assessment (LCA) of alternative (electric and hydrogen) and conventional diesel buses in a large metropolitan area. The primary focus was on hydrogen derived from coke oven gas a byproduct of the coking process which is a crucial step in the steel production value chain. The functional unit was 1000000 km traveled over 15 years. LCA analysis using SimaPro v9.3 revealed significant environmental differences between the bus types. Hydrogen buses outperformed electric buses in all 11 environmental impact categories and in 5 of 11 categories compared to conventional diesel buses. The most substantial improvements for hydrogen buses were observed in ozone depletion (8.6% of diesel buses) and global warming (29.9% of diesel buses). As a bridge to a future dominated by green hydrogen employing grey hydrogen from coke oven gas in buses provides a practical way to decrease environmental harm in regions abundant with this resource. This interim solution can significantly contribute to climate policy goals.

The use of green hydrogen as a high-energy fuel of the future may be an opportunity to balance the unstable energy system which still relies on renewable energy sources. This work is a comprehensive review of recent advancements in green hydrogen production. This review outlines the current energy consumption trends. It presents the tasks and challenges of the hydrogen economy towards green hydrogen including production purification transportation storage and conversion into electricity. This work presents the main types of water electrolyzers: alkaline electrolyzers proton exchange membrane electrolyzers solid oxide electrolyzers and anion exchange membrane electrolyzers. Despite the higher production costs of green hydrogen compared to grey hydrogen this review suggests that as renewable energy technologies become cheaper and more efficient the cost of green hydrogen is expected to decrease. The review highlights the need for cost-effective and efficient electrode materials for large-scale applications. It concludes by comparing the operating parameters and cost considerations of the different electrolyzer technologies. It sets targets for 2050 to improve the efficiency durability and scalability of electrolyzers. The review underscores the importance of ongoing research and development to address the limitations of current electrolyzer technology and to make green hydrogen production more competitive with fossil fuels.

Acting in accordance with the requirements of the 2015 Paris Agreement Poland as well as other European Union countries have committed to achieving climate neutrality by 2050. One of the solutions to reduce emissions of harmful substances into the environment is the implementation of large-scale hydrogen technologies. This article presents the cost of producing green hydrogen produced using an alkaline electrolyzer with electricity supplied from a photovoltaic farm. The analysis was performed using the Monte Carlo method and for baseline assumptions including an electricity price of 0.053 EUR/kWh the cost of producing green hydrogen was 5.321 EUR/kgH2 . In addition this article presents a sensitivity analysis showing the impact of the electricity price before and after the energy crisis and other variables on the cost of green hydrogen production. The large change occurring in electricity prices (from 0.035 EUR/kWh to 0.24 EUR/kWh) significantly affected the levelized cost of green hydrogen (LCOH) which could change by up to 14 EUR/kgH2 in recent years. The results of the analysis showed that the parameters that successively have the greatest impact on the cost of green hydrogen production are the operating time of the plant and the unit capital expenditure. The development of green hydrogen production facilities along with the scaling of technology in the future can reduce the cost of its production.

This article describes an example of using the measurement data from photovoltaic systems and wind turbines to perform practical probabilistic calculations around green hydrogen generation. First the power generated in one month by a ground-mounted photovoltaic system with a peak power of 3 MWp is described. Using the Metalog family of probability distributions the probability of generating selected power levels corresponding to the amount of green hydrogen produced is calculated. Identical calculations are performed for the simulation data allowing us to determine the power produced by a wind turbine with a maximum power of 3.45 MW. After interpolating both time series of the power generated by the renewable energy sources to a common sampling time they are summed. For the sum of the power produced by the photovoltaic system and the wind turbine the probability of generating selected power levels corresponding to the amount of green hydrogen produced is again calculated. The presented calculations allow us to determine with probability distribution accuracy the amount of hydrogen generated from the energy sources constituting a mix of photovoltaics and wind. The green hydrogen production model includes the hardware and the geographic context. It can be used to determine the preliminary assumptions related to the production of large amounts of green hydrogen in selected locations. The calculations presented in this article are a practical example of Business Intelligence.