Applications & Pathways

Numerous studies concerning the life cycle assessment of fuel cell vehicles (FCVs) have been conducted. However little attention has been paid to the life cycle assessment of an FCV from the perspective of the detailed vehicle components. This work conducts the life cycle assessment of Toyota Mirai with all major components considered in a Chinese context. Both the vehicle cycle and the fuel cycle are included. Both comprehensive resources and energy consumption and comprehensive environmental emissions of the life cycles are investigated. Potential environmental impacts are further explored based on CML 2001 method. Then different hydrogen production schemes are compared to obtain the most favorable solution. To explore the potential of the electrolysis the scenario analysis of the power structure is conducted. The results show that the most mineral resources are consumed in the raw material acquisition stage the most fossil energy is consumed in the use stage and global warming potential (GWP) value is fairly high in all life cycle stages of Toyota Mirai using electrolyzed hydrogen. For hydrogen production schemes the scenario analysis indicates that simply by optimizing the power structure the environmental impact of the electrolysis remains higher than other schemes. When using the electricity from hydropower or wind power the best choice will be the electrolysis.

In the present study a hydrogen and oxygen heat-sink engine thrust chamber and the corresponding injection faceplate with discrete slot orifices are devised to study the cooling performance near the faceplate region. Moreover a set of experiments and numerical simulations are conducted to evaluate the effects of various factors on combustion performance and film cooling efficiency. According to the obtained result the circumferential cooling efficiency has an M-shaped distribution in the near-injector region. Furthermore it has been discovered that when the film flow ratio increases so does the cooling efficiency. This is especially more pronounced in the range of 30–80 mm from the faceplate. The cooling efficiency is found to be proportional to the film flow rate ratio’s 0.4 power. Compared with the slot thickness the reduction in the slot width is more beneficial in improving the cooling efficiency and the advantage is more prominent for small film flow ratios. In addition when the amount of coolant is not enough the cooling effect of the discrete slot film orifice is better than that of the common cylindrical orifice. The present article demonstrates that setting the area ratio of the adjacent film orifices is an effective way to reduce the uneven circumferential distribution of the wall surface temperature.

The article presents the methodology and applicable data for the generation of life cycle inventory for conventional and alternative processes for base chemical production by process simulation. Addressed base chemicals include lower olefins BTX aromatics methanol ammonia and hydrogen. Assessed processes include conventional chemical production processes from naphtha LPG natural gas and heavy fuel oil; feedstock recycling technologies via gasification and pyrolysis of refuse derived fuel; and power-to-X technologies from hydrogen and CO2. Further process variations with additional hydrogen input are covered. Flowsheet simulation in Aspen Plus is applied to generate datasets with conclusive mass and energy balance under uniform modelling and assessment conditions with available validation data. Process inventory data is generated with no regard to the development stage of the respective technology but applicable process data with high technology maturity is prioritized for model validation. The generated inventory data can be applied for life cycle assessments. Further the presented modelling and balancing framework can be applied for inventory data generation of similar processes to ensure comparability in life cycle inventory data.

This paper covers the hydrogen technologies regarding the role of hydrogen as an energy carrier and the possibilities of its production and use. It is initially presented the modalities and the efficiency of the current technologies of obtaining hydrogen detailing its obtaining by the electrolysis of the water the electrochemical efficiency and the specific consumption of electricity as well as the thermodynamics of the electrochemical processes. The following paragraph addresses hydrogen conversion possibilities. This paragraph details the thermodynamic analysis of the fuel cell the external characteristic of the fuel cell and the types of fuel cell. The last paragraph addresses the possibilities of using the fuel cells for electrical vehicles and cogeneration systems for buildings.In this context the traditional transport and distribution grid will have to adapt to the new realities as they will need to actively participate in the internal energy market by the transformation of the traditional electricity grid in energy flow from unidirectional to bidirectional through the production of hydrogen offering the same facilities as the gas grid.

The utilization of hydrogen energy is important for achieving a low-carbon society. Japan has set ambitious goals for hydrogen stations and fuel cell vehicles focusing on the introduction and dissemination of self-refuelling systems. This paper evaluates public trust in the fuel equipment and self-handling technology related to self-refuelling hydrogen stations and compares it with that for widespread gasoline stations. To this end the results of an online survey of 300 people with Japanese driver licenses are reported and analyzed. The results show that trust in the equipment and self-handling is more important for the user than trust in the fuel. In addition to introduce and disseminate new technology such as hydrogen stations users must be made aware of the risk of using the technology until it becomes as familiar as existing gasoline station technology.

This paper provides a comprehensive review and critical analysis of the latest research results in addition to an overview of the future challenges and opportunities regarding the use of hydrogen to power internal combustion engines (ICEs). The experiences and opinions of various international research centers on the technical possibilities of using hydrogen as a fuel in ICE are summarized. The advantages and disadvantages of the use of hydrogen as a solution are described. Attention is drawn to the specific physical chemical and operational properties of hydrogen for ICEs. A critical review of hydrogen combustion concepts is provided drawing on previous research results and experiences described in a number of research papers. Much space is devoted to discussing the challenges and opportunities associated with port and direct hydrogen injection technology. A comparison of different fuel injection and ignition strategies and the benefits of using the synergies of selected solutions are presented. Pointing to the previous experiences of various research centers the hazards related to incorrect hydrogen combustion such as early pre‐ignition late pre‐ignition knocking combustion and backfire are described. Attention is focused on the fundamental importance of air ratio optimization from the point of view of combustion quality NOx emissions engine efficiency and performance. Exhaust gas scrubbing to meet future emission regulations for hydrogen powered internal combustion engines is another issue that is considered. The article also discusses the modifications required to adapt existing engines to run on hydrogen. Referring to still‐unsolved problems the reliability challenges faced by fuel injection systems in particular are presented. An analysis of more than 150 articles shows that hydrogen is a suitable alternative fuel for spark‐ignition engines. It will significantly improve their performance and greatly reduce emissions to a fraction of their current level. However its use also has some drawbacks the most significant of which are its high NOx emissions and low power output and problems in terms of the durability and reliability of hydrogen‐fueled engines.

As the use of fossil fuels becomes more and more restricted there is a need for alternative fuels also at sea. For short sea distance travel purposes batteries may be a solution. However for longer distances when there is no possibility of recharging at sea batteries do not have sufficient capacity yet. Several projects have demonstrated the use of compressed hydrogen (CH₂) as a fuel for road transport. The experience with hydrogen as a maritime fuel is very limited. In this paper the similarities and differences between liquefied hydrogen (LH₂) and liquefied natural gas (LNG) as a maritime fuel will be discussed based on literature data of their properties and our system knowledge. The advantages and disadvantages of the two fuels will be examined with respect to use as a maritime fuel. Our objective is to discuss if and how hydrogen could replace fossil fuels on long distance sea voyages. Due to the low temperature of LH₂ and wide flammability range in air these systems have more challenges related to storage and processing onboard than LNG. These factors result in higher investment costs. All this may also imply challenges for the LH₂ supply chain.

It is now well established that electrochemical systems can optimally perform only within a narrow range of temperature. Exposure to temperatures outside this range adversely affects the performance and lifetime of these systems. As a result thermal management is an essential consideration during the design and operation of electrochemical equipment and can heavily influence the success of electrochemical energy technologies. Recently significant attempts have been placed on the maturity of cooling technologies for electrochemical devices. Nonetheless the existing reviews on the subject have been primarily focused on battery cooling. Conversely heat transfer in other electrochemical systems commonly used for energy conversion and storage has not been subjected to critical reviews. To address this issue the current study gives an overview of the progress and challenges on the thermal management of different electrochemical energy devices including fuel cells electrolysers and supercapacitors. The physicochemical mechanisms of heat generation in these electrochemical devices are discussed in-depth. Physics of the heat transfer techniques currently employed for temperature control are then exposed and some directions for future studies are provided.

Using electricity for heating can contribute to decarbonization and provide flexibility to integrate variable renewable energy. We analyze the case of electric storage heaters in German 2030 scenarios with an open-source electricity sector model. We find that flexible electric heaters generally increase the use of generation technologies with low variable costs which are not necessarily renewables. Yet making customary night-time storage heaters temporally more flexible offers only moderate benefits because renewable availability during daytime is limited in the heating season. Respective investment costs accordingly have to be very low in order to realize total system cost benefits. As storage heaters feature only short-term heat storage they also cannot reconcile the seasonal mismatch of heat demand in winter and high renewable availability in summer. Future research should evaluate the benefits of longer-term heat storage.

The percentage of the population in urban areas has increased by ten points from 2000 (46%) to 2020 (56%); it is expected to reach up to 70% by 2050. This undoubtedly will encourage society to use alternative transports. On the other hand the widespread fear of pandemics seems to be here to stay and it is causing most people to leave public transport to use private cars and a few have chosen unipersonal electric vehicles. As a consequence the decision of using private cars negatively affects the air quality and consequently urban population health. This paper aims to demonstrate a sustainable solution for urban mobility based on a hydrogen powered unipersonal electric vehicle which as shown provides great advantages over the conventional battery powered unipersonal electric vehicle. To show this the authors have developed both vehicles in comparable versions using the same platform and ensuring that the total weight of the unipersonal electric vehicle was the same in both cases. They have been subjected to experimental tests that support the features of the hydrogen-based configuration versus the battery-based one including higher specific energy more autonomy and shorter recharge time.

In recent years the frequency of power demand imbalance and negative price phenomenon has risen due to the rapid expansion of renewable energy sources (RES). Because of this a means to reduce the curtailment of RES by utilizing surplus energy is essential. This paper focuses on reducing the curtailment of wind turbines (WT) with high output intermittency and minimizing the investment cost of IES via an integrated energy system (IES). The IES operation seeks to improve the acceptability and efficiency of the RES as it supports the integration of various energies mix such as electricity heat hydrogen. This paper proposes an optimal facility combination set (FCS) of IES that satisfies the requirements of ISO and IPP using Multi-Objective Optimization Programming (MOP). The case study is based on a wind farm in South Korea set in Aewol-eup Jeju-Island. The case study results provide the best configuration of the IES energy mix with the best economic value and efficiency while satisfying ISO and IPP perspectives.

The use of hydrogen as an alternative to fossil fuels for vehicle propulsion is already a reality. However due to its physical characteristics storage is still a challenge. There is an innovative way presented in this study to store hydrogen in conventional vehicles propelled by spark-ignition reciprocating engines and fuel cells using hydrogen as fuel; the storage of hydrogen will be at high pressure within small spheres randomly packed in a tank like the conventional tank of fuel used nowadays in current vehicles. Therefore the main purpose of the present study is to assess the performance of this storage system and compare it to others already applied by car manufacturers in their cars. In order to evaluate the performance of this storage system some parameters were taken into account: The energy stored by volume and stored by weight hydrogen leakage and compliance with current standards. This system is safer than conventional storage systems since hydrogen is stored inside small spheres containing small amounts of hydrogen. Besides its gravimetric energy density (GED) is threefold and the volumetric energy density (VED) is about half when compared with homologous values for conventional systems and both exceed the targets set by the U.S. Department of Energy. Regarding the leakage of hydrogen it complies with the European Standards provided a suitable choice of materials and dimensions is made.

Delft University of Technology under its ‘‘Green Village” programme has an initiative to build a power plant (car parking lot) based on the fuel cells used in vehicles for motive power. It is a trigeneration system capable of producing electricity heat and hydrogen. It comprises three main zones: a hydrogen production zone a parking zone and a pump station zone. This study focuses mainly on the hydrogen production zone which assesses four different system designs in two different operation modes of the facility: Car as Power Plant (CaPP) mode corresponding to the open period of the facility which uses fuel cell electric vehicles (FCEVs) as energy and water producers while parked; and Pump mode corresponding to the closed period which compresses the hydrogen and pumps to the vehicle’s fuel tank. These system designs differ by the reforming technology: the existing catalytic reformer (CR) and a solid oxide fuel cell operating as reformer (SOFCR); and the option of integrating a carbon capture and storage (CCS). Results reveal that the SOFCR unit significantly reduces the exergy destruction resulting in an improvement of efficiency over 20% in SOFCR-based system designs compared to CR-based system designs in both operation modes. It also mitigates the reduction in system efficiency by integration of a CCS unit achieving a value of 2% whereas in CR-based systems is 7–8%. The SOFCR-based system running in Pump mode achieves a trigeneration efficiency of 60%.

Automotive proton-exchange membrane fuel cells (PEMFCs) have finally reached a state of technological readiness where several major automotive companies are commercially leasing and selling fuel cell electric vehicles including Toyota Honda and Hyundai. These now claim vehicle speed and acceleration refueling time driving range and durability that rival conventional internal combustion engines and in most cases outperform battery electric vehicles. The residual challenges and areas of improvement which remain for PEMFCs are performance at high current density durability and cost. These are expected to be resolved over the coming decade while hydrogen infrastructure needs to become widely available. Here we briefly discuss the status of automotive PEMFCs misconceptions about the barriers that platinum usage creates and the remaining hurdles for the technology to become broadly accepted and implemented.

The information in this report covers the period January 2019 – December 2019. The technology and market module of the FCHO presents a range of statistical data as an indicator of the health of the sector and the progress in market development over time. This includes statistical information on the size of the global fuel cell market including number and capacity of fuel cell systems shipped in a calendar year. For this first edition data to the end of 2019 is presented where possible alongside analysis of key sector developments. Fuel cell system shipments for each calendar year are presented both as numbers of units and total system megawatts. The data are further divided and subdivided by: • Application: Total system shipments are divided into Transport Stationary and Portable applications • Fuel cell type: Numbers are provided for each of the different fuel cell chemistry types • Region of integration: Region where the final manufacturer – usually the system integrator – integrates the fuel cell into the final product • Region of deployment: Region where the final product was shipped to for deployment The data is sourced directly from industry players as well as other relevant sources including press releases associations and other industry bodies.

Energy-related GHG emissions mainly from fossil fuels combustion account for around 70% of total emissions. Those emissions are the target of the recent sustainability policies. Indeed renewables exploitation is considered widely the weapon to deal with this challenge thanks to their carbon neutrality. But the biggest drawback is represented by the mismatching between their production and users consumption. The storage would be a possible solution but its viability consists of economic sustainability and energy process efficiency as well. The cutting edge technologies of batteries have not still solved these issues at the same time. So a paradigm shift towards the identification of an energy carrier as storage option the so called Power-to-Gas could be the viable solution. From viability to feasibility a mandatory step is required: the opportunity to integrate the new solution in the proven infrastructures system. Thus the recent studies on Hydrogen (H2) enrichment in Natural Gas demonstrating a lower environmental impact and an increase in energy performance are the base to build the hydrogen transition in the urban environment. The aim of this paper is to evaluate the environmental benefits at building and district scale.

The search for fossil fuels substitutes forces the use of new propulsion technologies applied to means of transportation. Already widespread hybrid vehicles are beginning to share the market with hydrogen-powered propulsion systems. These systems are fuel cells or internal combustion engines powered by hydrogen fuel. In this context road tests of a hydrogen fuel cell drive were conducted under typical traffic conditions according to the requirements of the RDE test. As a result of the carried-out work energy flow conditions were presented for three driving phases (urban rural and motorway). The different contributions to the vehicle propulsion of the hydrogen system and the electric system in each phase of the driving route are indicated. The characteristic interaction of power train components during varying driving conditions was presented. A wide variation in the contribution of the fuel cell and the battery to the vehicle’s propulsion was identified. In urban conditions the share of the fuel cell in the vehicle’s propulsion is more than three times that contributed by the battery suburban—7 times highway—28 times. In the entire test the ratio of FC/BATT use was more than seven while the energy consumption was more than 22 kWh/100 km. The amounts of battery energy used and recovered were found to be very close to each other under RDE test conditions.

Reducing the cost of delivering hydrogen to fuelling stations and dispensing it into fuel cell electric vehicles (FCEVs) is one critical element of efforts to increase the cost-competitiveness of FCEVs. Today hydrogen is primarily delivered to stations by trucks. Pipeline delivery is much rarer: one urban U.S. station has been supplied with 800-psi hydrogen from an industrial hydrogen pipeline since 2011 and a German station on the edge of an industrial park has been supplied with 13000-psi hydrogen from a pipeline since 2006. This article compares the economics of existing U.S. hydrogen delivery methods with the economics of a high-pressure scalable intra-city pipeline system referred to here as the “HyLine” system. In the HyLine system hydrogen would be produced at urban industrial or commercial sites compressed to 15000 psi stored at centralized facilities delivered via high-pressure pipeline to retail stations and dispensed directly into FCEVs. Our analysis of retail fuelling station economics in Los Angeles suggests that as FCEV demand for hydrogen in an area becomes sufficiently dense pipeline hydrogen delivery gains an economic advantage over truck delivery. The HyLine approach would also enable cheaper dispensed hydrogen compared with lower-pressure pipeline delivery owing to economies of scale associated with integrated compression and storage. In the largest-scale fuelling scenario analyzed (a network of 24 stations with capacities of 1500 kg/d each and hydrogen produced via steam methane reforming) HyLine could potentially achieve a profited hydrogen cost of $5.3/kg which is approximately equivalent to a gasoline cost of $2.7/gal (assuming FCEVs offer twice the fuel economy of internal combustion engine vehicles and vehicle cost is competitive). It is important to note that significant effort would be required to develop technical knowledge codes and standards that would enable a HyLine system to be viable. However our preliminary analysis suggests that the HyLine approach merits further consideration based on its potential economic advantages. These advantages could also include the value of minimizing retail space used by hydrogen compression and storage sited at fuelling stations which is not reflected in our analysis.

Extreme halophiles offer the advantage to save on the costs of sterilization and water for biohydrogen production from lignocellulosic waste after the pretreatment process with their ability to withstand extreme salt concentrations. This study identifies the dominant hydrogen-producing genera and species among the acclimatized extremely halotolerant microbial communities taken from two salt-damaged soil locations in Khon Kaen and one location from the salt evaporation pond in Samut Sakhon Thailand. The microbial communities’ V3–V4 regions of 16srRNA were analyzed using high-throughput amplicon sequencing. A total of 345 operational taxonomic units were obtained and the high-throughput sequencing confirmed that Firmicutes was the dominant phyla of the three communities. Halanaerobium fermentans and Halanaerobacter lacunarum were the dominant hydrogen-producing species of the communities. Spatial proximity was not found to be a determining factor for similarities between these extremely halophilic microbial communities. Through the study of the microbial communities strategies can be developed to increase biohydrogen molar yield.

The need to significantly reduce emissions from the steelmaking sector requires effective and ready-to-use technical solutions. With this aim different decarbonization strategies have been investigated by both researchers and practitioners. To this concern the most promising pathway is represented by the replacement of natural gas with pure hydrogen in the direct reduced iron (DRI) production process to feed an electric arc furnace (EAF). This solution allows to significantly reduce direct emissions of carbon dioxide from the DRI process but requires a significant amount of electricity to power electrolyzers adopted to produce hydrogen. The adoption of renewable electricity sources (green hydrogen) would reduce emissions by 95–100% compared to the blast furnace–basic oxygen furnace (BF–BOF) route. In this work an analytical model for the identification of the minimum emission configuration of a green energy–steel system consisting of a secondary route supported by a DRI production process and a renewable energy conversion system is proposed. In the model both technological features of the hydrogen steel plant and renewable energy production potential of the site where it is to be located are considered. Compared to previous studies the novelty of this work consists of the joint modeling of a renewable energy system and a steel plant. This allows to optimize the overall system from an environmental point of view considering the availability of green hydrogen as an inherent part of the model. Numerical experiments proved the effectiveness of the model proposed in evaluating the suitability of using green hydrogen in the steelmaking process. Depending on the characteristics of the site and the renewable energy conversion system adopted decreases in emissions ranging from 60% to 91% compared to the BF–BOF route were observed for the green energy–steel system considered It was found that the environmental benefit of using hydrogen in the secondary route is strictly related to the national energy mix and to the electrolyzers’ technology. Depending on the reference context it was found that there exists a maximum value of the emission factor from the national electricity grid below which is environmentally convenient to produce DRI by using only hydrogen. It was moreover found that the lower the electricity consumption of the electrolyzer the higher the value assumed by the emission factor from the electricity grid which makes the use of hydrogen convenient.

Power to hydrogen (P2H) provides a promising solution to the geographic mismatch between sources of renewable energy and the market due to its technological maturity flexibility and the availability of technical and economic data from a range of active demonstration projects. In this review we aim to provide an overview of the status of P2H analyze its technical barriers and solutions and propose potential opportunities for future research and industrial demonstrations. We specifically focus on the transport of hydrogen via natural gas pipeline networks and end-user purification. Strong evidence shows that an addition of about 10% hydrogen into natural gas pipelines has negligible effects on the pipelines and utilization appliances and may therefore extend the asset value of the pipelines after natural gas is depleted. To obtain pure hydrogen from hydrogen-enriched natural gas (HENG) mixtures end-user separation is inevitable and can be achieved through membranes adsorption and other promising separation technologies. However novel materials with high selectivity and capacity will be the key to the development of industrial processes and an integrated membrane-adsorption process may be considered in order to produce high-purity hydrogen from HENG. It is also worth investigating the feasibility of electrochemical separation (hydrogen pumping) at a large scale and its energy analysis. Cryogenics may only be feasible when liquefied natural gas (LNG) is one of the major products. A range of other technological and operational barriers and opportunities such as water availability byproduct (oxygen) utilization and environmental impacts are also discussed. This review will advance readers’ understanding of P2H and foster the development of the hydrogen economy.

The energy transition for a net-zero future will require deep decarbonisation that hydrogen is uniquely positioned to facilitate. This technoeconomic study considers renewable hydrogen production transmission and storage for energy networks using the National Electricity Market (NEM) region of Eastern Australia as a case study. Plausible growth projections are developed to meet domestic demands for gas out to 2040 based on industry commitments and scalable technology deployment. Analysis using the discounted cash flow technique is performed to determine possible levelised cost figures for key processes out to 2050. Variables include geographic limitations growth rates and capacity factors to minimise abatement costs compared to business-as-usual natural gas forecasts. The study provides an optimistic outlook considering renewable power-to-X opportunities for blending replacement and gas-to-power to show viable pathways for the gas transition to green hydrogen. Blending is achievable with modest (3%) green premiums this decade and substitution for natural gas combustion in the long-term is likely to represent an abatement cost of AUD 18/tCO₂-e including transmission and storage.

About 400 million tonnes of plastics are produced per annum worldwide. End-of-life of plastics disposal contaminates the waterways aquifers and limits the landfill areas. Options for recycling plastic wastes include feedstock recycling mechanical /material recycling industrial energy recovery municipal solid waste incineration. Incineration of plastics containing E-Wastes releases noxious odours harmful gases dioxins HBr polybrominated diphenylethers and other hydrocarbons. This study focusses on recycling options in particular feedstock recycling of plastics in high-temperature materials processing for a sustainable solution to the plastic wastes not suitable for recycling. Of the 7% CO₂ emissions attributed to the iron and steel industry worldwide ∼30% of the carbon footprint is reduced using the waste plastics compared to other carbon sources in addition to energy savings. Plastics have higher H₂ content than the coal. Hydrogen evolved from the plastics acts as the reductant alongside the carbon monoxide. Hydrogen reduction of iron ore in presence of plastics increases the reaction rates due to higher diffusion of H₂ compared to CO. Plastic replacement reduces the process temperature by at least 100–200 °C due to the reducing gases (hydrogen) which enhance the energy efficiency of the process. Similarly plastics greatly reduce the emissions in other high carbon footprint process such as magnesia production while contributing to energy.

The transition to hydrogen as a fuel source presents several challenges. One of the major hurdles is the cost-effective production of hydrogen in small quantities (less than 1MMscf/month). In the early demonstration phase hydrogen can be provided by bulk distribution of liquid or compressed gas from central production plants; however the next phase to fostering the hydrogen economy will likely include onsite generation and extensive pipeline networks to help effect a pervasive infrastructure. Providing inexpensive hydrogen at a fleet operator’s garage or local fuelling station is a key enabling technology for direct hydrogen Fuel Cell Vehicles (FCVs). The objective of this project was to develop a comprehensive turnkey stand-alone commercial hydrogen fuelling station for FCVs with state-of-the-art technology that is cost-competitive with current hydrocarbon fuels. Such a station would promote the advent of the hydrogen fuel economy for buses fleet vehicles and ultimately personal vehicles. Air Products partnering with the U.S. Department of Energy (DOE) The Pennsylvania State University Harvest Energy Technology and QuestAir developed a turnkey hydrogen fuelling station on the Penn State campus. Air Products aimed at designing a station that would have 65% overall station efficiency 82% PSA (pressure swing adsorption) efficiency and the capability of producing hydrogen at $3.00/kg (gge) H₂ at mass production rates. Air Products designed a fuelling station at Penn State from the ground up. This project was implemented in three phases. The first phase evaluated the various technologies available in hydrogen generation compression storage and gas dispensing. In the second phase Air Products designed the components chosen from the technologies examined. Finally phase three entailed a several-month period of data collection full-scale operation maintenance of the station and optimization of system reliability and performance. Based on field data analysis it was determined by a proprietary hydrogen-analysis model that hydrogen produced from the station at a rate of 1500 kg/day and when produced at 1000 stations per year would be able to deliver hydrogen at a price of $3.03/kg (gge) H₂. The station’s efficiency was measured to be 65.1% and the PSA was tested and ran at an efficiency of 82.1% thus meeting the project targets. From the study it was determined that more research was needed in the area of hydrogen fuelling. The overall cost of the hydrogen energy station when combined with the required plot size for scaled-up hydrogen demands demonstrated that a station using steam methane reforming technology as a means to produce on–site hydrogen would have limited utility in the marketplace. Alternative hydrogen supplies such as liquid or pipeline delivery to a refuelling station need to be included in the exploration of alternative energy site layouts. These avenues need to be explored before a definitive refuelling station configuration and commercialization pathway can be determined.

In order to favor a transition to a renewable energy economy it is necessary to study the possible permeation of renewable energy sources not only in the electric grid or industrial scale but also in the small householding scale. One of the most interesting technologies available for this purpose is solar energy since it is a mature technology that can be easily installed in every rooftop. Thus a techno-economic assessment was carried out to evaluate the installation of a solar-based power-heat hybrid microgrid considering the use of hydrogen as an energy vector in a typical residential house in Spain. Lead-acid batteries plus the photovoltaic and solar thermal energy installation are complemented with a hydrogen system composed of an electrolyzer two metal hydride bottles and a fuel cell. A simulation tool has been generated using experimental models developed and validated with real equipment for each one of the electric microgrid component. Three operating modes were tested making use of this tool to better manage the energy consumed/produced and optimize the economic output of the facility. The results show that setting up a hydrogen-based microgrid in a residential house is unviable today mainly due to the high cost of hydrogen generation and consumption equipment. If only solar energy is considered the microgrid inversion (12.500 €) is recovered in ten years. On the other hand selling the electricity output has almost no repercussions considering current electrical rates in Spain. Finally while using an optimization algorithm to manage energy use battery life-spam and economic benefit slightly increase. However this profit may not be enough to justify the use of a more complex control system. The results of this research will help users renewable energy companies investigators and policymakers to better understand the different factors influencing the spread of renewable smart grids in households and propose solutions to address these.