Temporal change analysis of public attitude,knowledge and acceptance of hydrogen vehicles in Greater Stavanger, 2006–2009

This study examines the trends of public opinions concerning the introduction of hydrogen vehicles in Greater Stavanger as well as public attitudes towards the natural environment over the course of the three-year period. This study is based on two surveys of the hydrogen highway project (HyNor) which were collected in the Greater Stavanger region, the west coast of Norway, between 2006 and 2009 (n=2000). The results of the study highlight that – despite an increased awareness of hydrogen vehicles – the proportions of those with pro-environment attitudes who support hydrogen vehicles’ introduction decreased between 2006 and 2009. The results reveal that knowledge about sustainable environment can affect hydrogen energy's acceptance whereas the level of pro-environment attitudes can increase not only public acceptance of hydrogen vehicles, but also people's willingness to pay for hydrogen fuels. These results were consistently found throughout the observed periods, based on the Greater Stavanger's case. A set of recommendations was discussed to improve public acceptance of hydrogen vehicles, and the next avenue of research regarding analysis of public acceptance and awareness about hydrogen vehicles was proposed.     

Optimal design of wind-powered hydrogen refuelling station for some selected cities of South Africa

The transport sector is considered as one of the sectors producing high carbon emissions worldwide due to the use of fossil fuels. Hydrogen is a non-toxic energy carrier that could serve as a good alternative to fossil fuels. The use of hydrogen vehicles could help reduce carbon emissions thereby cutting down on greenhouse gases and environmental pollution. This could largely be achieved when hydrogen is produced from renewable energy sources and is easily accessible through a widespread network of hydrogen refuelling stations. In this study, the techno-economic assessment was performed for a wind-powered hydrogen refuelling station in seven cities of South Africa. The aim is to determine the optimum configuration of a hydrogen refuelling station powered by wind energy resources for each of the cities as well as to determine their economic viability and carbon emission reduction capability. The stations were designed to cater for 25 hydrogen vehicles every day, each with a 5 kg tank capacity. The results show that a wind-powered hydrogen refuelling station is viable in South Africa with the cost of hydrogen production ranging from 6.34 $/kg to 8.97 $/kg. These costs are competitive when compared to other costs of hydrogen production around the world. The cities located in the coastal region of South Africa are more promising for siting wind powered-hydrogen refuelling station compared to the cities located on the mainland. The hydrogen refuelling stations could reduce the CO₂ and CO emissions by 73.95 tons and 0.133 tons per annum, respectively.     

Integration of a light mobility urban scale hydrogen refuelling station for cycling purposes in the transportation market

Road transportation consists of a significant contributor to total greenhouse gas emissions in developed countries. New alternative technologies in transportation such as electric vehicles aim to reduce substantially vehicle emissions, particularly in urban areas. Incentives of using two-wheel electric vehicles such as bicycles in big cities centres are promoted by local governments, and in fact, some countries are already trying to adopt this transition. An interesting case consists of the use of hydrogen fuel cells in such vehicles to increase their driving range under short refuelling times. To this end, this paper investigated the social and financial prospects of hydrogen infrastructure for city-oriented fuel cell electric vehicles such as bicycles. The results of the research indicated that a light mobility urban hydrogen refuelling station able to provide refuelling processes at pressures of 30 bar with a hydrogen fuel cost of 34.7 €/kgH₂ is more favourable compared to larger stations.     

Supporting green Urban mobility – The case of a small-scale autonomous hydrogen refuelling station

Nowadays, the development of hydrogen economy in the transportation sector is hindered by the principal barriers arising from the lack of adequate infrastructure and the small fleet of hydrogen-based road vehicles.This study investigates the potential of small-scale autonomous hydrogen refuelling stations with onsite production via an alkaline electrolysis apparatus powered by a small wind turbine. In this context, an urban area with promising wind resources has been selected. Based on the wind conditions and an indicative hydrogen demand for refuelling light-duty fuel cell electric vehicles such as bicycles, the sizing of the wind turbine and the electrolyser has been theoretically calculated. For supporting the daily hydrogen refuelling demand of the fuel cell electric bicycles, which is estimated at approximately 6 kg, it is calculated that a 50 kW wind turbine should be installed in order to power a 70 kW alkaline electrolyser for producing hydrogen. The capital cost of the hydrogen station is calculated at €248,130, while the retail price of the produced hydrogen is estimated to be more than 50.2 €/kg_H2 in order to achieve a positive internal rate of return.Ultimately, the present paper aims at delivering a feasibility study of a small-scale H₂ refuelling station for fuel cell bicycles in order to provide investors with initiatives to implement such schemes in urban environments where problems of low air quality and high traffic are intense.     

Design of a solar hydrogen refuelling station following the development of the first Croatian fuel cell powered bicycle to boost hydrogen urban mobility

Hydrogen refuelling stations are important for achieving sustainable hydrogen economy in low carbon transport and fuel cell electric vehicles. The solution presented in this paper provides us with a technology for producing carbon dioxide free hydrogen, which is an approach that goes beyond the existing large-scale hydrogen production technologies that use fossil fuel reforming. Hence, the main goal of this work was to design a hydrogen refuelling station to secure the autonomy of a hydrogen powered bicycle. The bicycle hydrogen system is equipped with a proton exchange membrane fuel cell stack of 300 W, a DC/DC converter, and a metal hydride storage tank of 350 NL of hydrogen. The hydrogen power system was made of readily available commercial components. The hydrogen station was designed as an off-grid system in which the installed proton exchange membrane electrolyzer is supplied with electric energy by direct conversion using photovoltaic cells. With the hydrogen flow rate of 2000 cc min⁻¹ the hydrogen station is expected to supply at least 5 bicycles to be used in 20 km long city tourist routes.     

Societal acceptance of hydrogen for domestic and export applications in Australia

With the urgent need to decarbonise the world's energy system, clean hydrogen is emerging as a potential technological solution. As with any new technology, understanding the public's response to hydrogen is critical to its success. Most studies examining public attitudes towards hydrogen have focused on refuelling stations and transport options. As a first of its kind, using a national survey (N = 2785) we evaluate the Australian public's response towards hydrogen for domestic and export use. In Australia, acceptance of hydrogen in domestic applications was influenced by its relative cost, ability to reduce air pollution and associated health benefits. Further, support for a hydrogen export industry was influenced by levels of trust in the government to manage the associated risks and the industry's commitment to climate protection. The paper concludes that effective, nuanced communication and engagement along with supporting financial policies will be critical in facilitating societal acceptance of hydrogen in Australia.     

Development of a hydrogen fuelling infrastructure in the Northeast U.S.A.

Development of critical selection criteria was undertaken, identifying locations for possible hydrogen refuelling stations depending on population density, demographics and traffic density. This identified suitable locations for the initial installations of refuelling stations when the first hydrogen fuel cell vehicles became commercially available. This was continued through the three time phases to implement an expanding network of refuelling stations to service demand and ensure consumer convenience.     

Making markets for hydrogen vehicles: Lessons from LPG

The adoption of liquefied petroleum gas vehicles is strongly linked to the break-even distance at which they have the same costs as conventional cars, with very limited market penetration at break-even distances above 40,000 km. Hydrogen vehicles are predicted to have costs by 2030 that should give them a break-even distance of less than this critical level. It will be necessary to ensure that there are sufficient refuelling stations for hydrogen to be a convenient choice for drivers. While additional LPG stations have led to increases in vehicle numbers, and increases in vehicles have been followed by greater numbers of refuelling stations, these effects are too small to give self-sustaining growth. Supportive policies for both vehicles and refuelling stations will be required.     

Assessing the operation and different refuelling cost scenarios of a fuel cell electric bicycle under low-pressure hydrogen storage

The transition to low- or zero-emission vehicles in the transportation sector is a challenging task toward meeting the greenhouse gas emission targets set by the majority of countries. One way of achieving this goal is to utilise hydrogen gas via fuel cell electric vehicles. This paper investigates the operation, driving range and refuelling process of a fuel cell electric bicycle. The methodology applied includes an estimation of the bike's range under different routes and riders, the riders' opinions and a financial evaluation of the hydrogen fuel cost compared to other urban vehicle alternatives. The results showed a minimum median range-to-energy consumption ratio of 20.5 km/kWh, while the maximum hydrogen cost was found to reach 0.025 €/km when refuelling the hydrogen bicycle in an autonomous hydrogen station. The outcome of this study indicates that the introduction of light-duty hydrogen vehicles in urban transportation may adequately meet the average daily driving distance of city residents.     

The simulation and analysis of leakage and explosion at a renewable hydrogen refuelling station

The number of hydrogen refuelling stations (HRSs) is steadily growing worldwide. In China, the first renewable hydrogen refuelling station has been built in Dalian for nearly 3 years. FLACS software based on computational fluid dynamics approach is used in this paper for simulation and analysis on the leakage and explosion of hydrogen storage system in this renewable hydrogen refuelling station. The effects of wind speed, leakage direction and wind direction on the consequences of the accident are analyzed. The harmful area, lethal area, the farthest harmful distance and the longest lethal distance in explosion accident of different accident scenarios are calculated. Harmful areas after explosion of different equipments in hydrogen storage system are compared. The results show that leakage accident of the 90 MPa hydrogen storage tank cause the greatest harm in hydrogen explosion. The farthest harmful distance caused by explosion is 35.7 m and the farthest lethal distance is 18.8 m in case of the same direction of wind and leakage. Moreover, it is recommended that the hydrogen tube trailer should not be parked in the hydrogen refuelling station when the amount of hydrogen is sufficient.     

Plug-in hybrid fuel cell vehicles market penetration scenarios

The main objective of this research is to analyze the impact of the market share increase of hydrogen based road vehicles in terms of energy consumption and CO₂, on today's Portuguese light-duty fleet. Actual yearly values of energy consumption and emissions were estimated using COPERT software: 167112 TJ of fossil fuel energy, 12213 kton of CO₂ emission and 141 kton of CO, 20 kton of HC, 46 kton of NO_x and 3 kton of PM. These values represent 20–40% of countries total emissions. Additionally to base fleet, three scenarios of introduction of 10–30% fuel cell vehicles including plug-in hybrids configurations were analysed. Considering the scenarios of increasing hydrogen based vehicles penetration, up to 10% life cycle energy consumption reduction can be obtained if hydrogen from centralized natural gas reforming is considered. Full life cycle CO₂ emissions can also be reduced up to 20% in these scenarios, while local pollutants reach up to 85% reductions. For the purpose of estimating road vehicle technologies energy consumption and CO₂ emissions in a full life cycle perspective, fuel cell, conventional full hybrids and hybrid plug-in technologies were considered with diesel, gasoline, hydrogen and biofuel blends. Energy consumption values were estimated in a real road driving cycle and with ADVISOR software. Materials cradle-to-grave life cycle was estimated using GREET database adapted to Europe electric mix. The main conclusions on CO₂ full life cycle analysis is that light-duty vehicles using fuel cell propulsion technology are highly dependent on hydrogen production pathway. The worst scenario for the current Portuguese and European electric mix is hydrogen produced from on-site electrolysis (in the refuelling stations). In this case full life cycle CO₂ is 270 g/km against 190 g/km for conventional Diesel vehicle, for a typical 150,000 km useful life.     

Experimental study on hydrogen explosions in a full-scale hydrogen filling station model

In order for fuel cell vehicles to develop a widespread role in society, it is essential that hydrogen refuelling stations become established. For this to happen, there is a need to demonstrate the safety of the refuelling stations. The work described in this paper was carried out to provide experimental information on hydrogen outflow, dispersion and explosion behaviour. In the first phase, homogeneous hydrogen–air mixtures of a known concentration were introduced into an explosion chamber and the resulting flame speed and overpressures were measured. Hydrogen concentration was the dominant factor influencing the flame speed and overpressure. Secondly, high-pressure hydrogen releases were initiated in a storage room to study the accumulation of hydrogen. For a steady release with a constant driving pressure, the hydrogen concentration varied as the inlet airflow changed, depending on the ventilation area of the room, the external wind conditions and also the buoyancy induced flows generated by the accumulating hydrogen. Having obtained this basic data, the realistic dispersion and explosion experiments were executed at full-scale in the hydrogen station model. High-pressure hydrogen was released from 0.8 to 8.0 mm nozzle at the dispenser position and inside the storage room in the full-scale model of the refuelling station. Also the hydrogen releases were ignited to study the overpressures that can be generated by such releases. The results showed that overpressures that were generated following releases at the dispenser location had a clear correlation with the time of ignition, distance from ignition point.     

Refuelling scenarios of a light urban fuel cell vehicle with metal hydride hydrogen storage. Comparison with compressed hydrogen storage counterpart

The high price of hydrogen fuel in the fuel cell vehicle refuelling market is highly dependent on the one hand from the production costs of hydrogen and on the other from the capital cost of a hydrogen refuelling station's components to support a safe and adequate refuelling process of contemporary fuel cell vehicles. The hydrogen storage technology dominated in the vehicle sector is currently based on high-pressure compressed hydrogen tanks to extend as much as possible the driving range of the vehicles. However, this technology mandates the use of large hydrogen compression and cooling systems as part of the refuelling infrastructure that consequently increase the final cost of the fuel. This study investigated the prospects of lowering the refuelling cost of small urban hydrogen vehicles through the utilisation of metal hydride hydrogen storage. The results showed that for low compression hydrogen storage, metal hydride storage is in favour in terms of the dispensed hydrogen fuel price, while its weight is highly comparable to the one of a compressed hydrogen tank. The final refuelling cost from the consumer's perspective however was found to be higher than the compressed gas due to the increased hydrogen quantity required to be stored in fully empty metal hydride tanks to meet the same demand.     

Techno-economic assessment of a hydrogen refuelling station powered by an on-grid photovoltaic solar system: A case study in Morocco

The present work sheds light on the green hydrogen future in Morocco. A detailed techno-economic assessment and evaluation of a hydrogen refuelling station powered by an on-grid photovoltaic system are presented and discussed. This station is designed to supply the fleet of taxis in a Moroccan city by assuming different scenarios to replace the current taxi system with fuel-cell electric vehicles. A model is proposed to estimate the daily demand for hydrogen, which is used to determine the sizing of the station's components. An economic analysis is then conducted to calculate the cost of hydrogen production. The technical results demonstrate that about 152 kg/day is required to supply the total fleet, while only 30.4 kg/day is enough to provide 20%. It is also found that the costs of hydrogen produced are inversely proportional to the capacity of the hydrogen refuelling station, and the hydrogen cost is about 9.18 $/kg for the larger station and 12.56 $/kg for the smaller one. The proposed system offers an attractive solution to enhance the country's development and reduce the consumption of hydrocarbon fuels.     

Analysis of the cost of hydrogen infrastructure for buses in London

The use of hydrogen (H₂) as transport fuel is often said to suffer from the ‘chicken and egg’ problem: vehicles that depend on H₂ cannot go on the roads due to the lack of an adequate infrastructure, and the almost non-existent fleet of H₂ vehicles on the roads makes it economically unsound to build a H₂ infrastructure.Although both hydrogen vehicles (fuel cell and internal combustion engine) and the related infrastructure have been (and are being) developed and some are commercially available, cost is seen as a major barrier. With today's technologies, H₂ only becomes competitive with petrol and diesel when produced at large quantities, suitable for supplying e.g. thousands of H₂ buses. The question is, how might this point be reached, and are there least cost infrastructural pathways to reach it. This paper tries to address the latter question, using the early development of a H₂ infrastructure for buses in London as a case study.The paper presents some of the analyses and results from a Ph.D. project (in progress) being undertaken at Imperial College London, funded by EPSRC (Grant GR/R50790/01). The results presented here illustrate that cost of hydrogen production and delivery vary mainly with levels of hydrogen demand and delivery distances, as well as other logistic criteria; least cost production–delivery pathways have been identified for various hydrogen demand scenarios and refuelling station set-ups. Another important conclusion is that the pattern of converting a group of refuelling stations to hydrogen (e.g. a group of refuelling stations for buses in London) has a significant effect on the unit cost of hydrogen.     

How risky is the introduction of fuel cell electric vehicles in a Mediterranean town?

The incorporation of Fuel Cell Electric Vehicles (FCEVs) in public transport is a fundamental step towards the minimization of the emissions due to transportation globally. In-depth studies are required regarding the potential risk from the storage of hydrogen, the transportation of hydrogen to refuelling stations and the refuelling procedure. Thus, it is a prerequisite to establish a holistic baseline which is related to FCEV safety during operation/maintenance, especially to a country in which the sales of these types of vehicles are significantly low. This paper suggests the employment of operational risk management methodology. Relevant experts and stakeholders requested to fill out an ‘‘Event-Probability Matrix’’ per scenario of likely hazards. This research estimates the interest of the local society about technological hazards and the conviction that hydrogen vehicles could be as safe as conventional vehicles. Additional critical scenarios related to the hydrogen storage are analyzed.     

Reinforcement learning based energy management systems and hydrogen refuelling stations for fuel cell electric vehicles: An overview

This paper examines the current state of the art of hydrogen refuelling stations-based production and storage systems for fuel cell hybrid electric vehicles (FCHEV). Nowadays, the emissions are increasing rapidly due to the usage of fossil fuels and the demand for hydrogen refuelling stations (HRS) is emerging to replace the conventional vehicles with FCHEVs. Hence, the availability of HRS and its economic aspects are discussed. In addition, a comprehensive study is presented on the energy storage systems such as batteries, supercapacitors and fuel cells which play a major role in the FCHEVs. An energy management system (EMS) is essential to meet the load requirement with effective utilisation of power sources with various optimizing techniques. A detailed comparative analysis is presented on the merits of Reinforcement learning (RL) for the FCHEVs. The significant challenges are discussed in depth with potential solutions for future work.     

Hydrogen quality sampling at the hydrogen refuelling station – lessons learnt on sampling at the production and at the nozzle

Fuel cell electric vehicles and hydrogen refuelling infrastructure are developing quickly in Europe, the USA and Asia. Hydrogen quality for transport applications requires compliance with ISO 14687-2: 2012 and EN 17124:2018 - this needs representative sampling, at the hydrogen production process and at hydrogen dispenser nozzle (which typically fill vehicles to a Nominal Working Pressure of either 35 or 70 MPa). The low thresholds in ISO 14687-2 for oxygen and water can be exceeded if the sampling procedure fails to purge the system sufficiently, which would lead to false results (60% in this study). Purging requirements to remove water were studied using a low pressure sampling rig. For hydrogen dispenser sampling using the Linde H2 Qualitizer (suitable for dispensing pressures up to 70 MPa), purging number and the effect of the initial fill level of a vehicle compressed hydrogen storage system were investigated experimentally to avoid hydrogen quality violation due to oxygen false positive. The study procedure reduces from 60% to 0% hydrogen quality violation. The next challenges highlighted are safe purging and reliable sampling of reactive contaminants in gas cylinders.     

Metal hydride hydrogen storage tank for fuel cell utility vehicles

The “low-temperature” intermetallic hydrides with hydrogen storage capacities below 2 wt% can provide compact H₂ storage simultaneously serving as a ballast. Thus, their low weight capacity, which is usually considered as a major disadvantage to their use in vehicular H₂ storage applications, is an advantage for the heavy duty utility vehicles. Here, we present new engineering solutions of a MH hydrogen storage tank for fuel cell utility vehicles which combines compactness, adjustable high weight, as well as good dynamics of hydrogen charge/discharge. The tank is an assembly of several MH cassettes each comprising several MH containers made of stainless steel tube with embedded (pressed-in) perforated copper fins and filled with a powder of a composite MH material which contains AB₂- and AB₅-type hydride forming alloys and expanded natural graphite. The assembly of the MH containers staggered together with heating/cooling tubes in the cassette is encased in molten lead followed by the solidification of the latter. The tank can provide >2 h long H₂ supply to the fuel cell stack operated at 11 kWe (H₂ flow rate of 120 NL/min). The refuelling time of the MH tank (T = 15–20 °C, P(H₂) = 100–150 bar) is about 15–20 min.     

Modelling and control of hydrogen and energy flows in a network of green hydrogen refuelling stations powered by mixed renewable energy systems

The planning of a hydrogen infrastructure with production facilities, distribution chains, and refuelling stations is a hard task. Difficulties may rise essentially in the choice of the optimal configurations. An innovative design of hydrogen network has been proposed in this paper. It consists of a network of green hydrogen refuelling stations (GHRSs) and several production nodes. The proposed model has been formulated as a mathematical programming, where the main decisions are the selection of GHRSs that are powered by the production nodes based on distance and population density criteria, as well the energy and hydrogen flows exchanged among the system components from the production nodes to the demand points. The approaches and methodologies developed can be taken as a support to decision makers, stakeholders and local authorities in the implementation of new hydrogen infrastructures. Optimal configurations have been reported taking into account the presence of an additional hydrogen industrial market demand and a connection with the electrical network. The main challenge that has been treated within the paper is the technical feasibility of the hydrogen supply chain, that is mainly driven by uncertain, but clean solar and wind energy resources. Using a Northern Italian case study, the clean hydrogen produced can be technically considered feasible to supply a network of hydrogen refuelling stations. Results show that the demands are satisfied for each time period and for the market penetration scenarios adopted.