Hydrogen Fuel Cell Electric Vehicles Research Articles

Comparison of well-to-wheels energy use and emissions of a hydrogen fuel cell electric vehicle relative to a conventional gasoline-powered internal combustion engine vehicle

The operation of hydrogen fuel cell electric vehicles (HFCEVs) is more efficient than that of gasoline conventional internal combustion engine vehicles (ICEVs), and produces zero tailpipe pollutant emissions. However, the production, transportation, and refueling of hydrogen are more energy- and emissions-intensive compared to gasoline. A well-to-wheels (WTW) energy use and emissions analysis was conducted to compare a HFCEV (Toyota Mirai) with a gasoline conventional ICEV (Mazda 3). Two sets of specific fuel consumption data were used for each vehicle: (1) fuel consumption derived from the U.S. Environmental Protection Agency's (EPA's) window-sticker fuel economy figure, and (2) weight-averaged fuel consumption based on physical vehicle testing with a chassis dynamometer on EPA's five standard driving cycles. The WTW results show that a HFCEV, even fueled by hydrogen from a fossil-based production pathway (via steam methane reforming of natural gas), uses 5%–33% less WTW fossil energy and has 15%–45% lower WTW greenhouse gas emissions compared to a gasoline conventional ICEV. The WTW results are sensitive to the source of electricity used for hydrogen compression or liquefaction.

Parametric analysis on multi-stage high pressure reducing valve for hydrogen decompression

Hydrogen fuel cell electric vehicle (FCEV) can reduce air pollution as well as achieve efficient use of hydrogen energy. Farther travel distance requires larger hydrogen storage pressure, thereby imposing more demanding working conditions on the pressure reducing system. In this paper, a multi-stage high pressure reducing valve (MSHPRV) for hydrogen decompression in FCEV is proposed, and the effects of different structural parameters on its internal flow characteristics are investigated to achieve a better hydrogen decompression process. Results show that compared with perforated plate, multi-stage perforated sleeves and valve core hold the dominant position in hydrogen throttling process. Larger multi-stage perforated sleeve diameter, perforated plate diameter and pressure ratio relate to larger hydrogen kinetic energy, turbulence vortex and energy consumption. However, with the increase of perforated plate stage and perforated plate radius, the turbulent intensity and energy consumption inside MSHPRV decreases correspondingly. This study can provide some technical supports for achieving hydrogen decompression in FCEV when facing harsh working conditions, or help with dealing energy conversion during decompression process.

Risk Assessment of Hydrogen Fuel Cell Electric Vehicles in Tunnels

The need to understand the risks and implications of traffic incidents involving hydrogen fuel cell electric vehicles in tunnels is increasing in importance with higher numbers of these vehicles being deployed. A risk analysis was performed to capture potential scenarios that could occur in the event of a crash and provide a quantitative calculation for the probability of each scenario occurring, with a qualitative categorization of possible consequences. The risk analysis was structured using an event sequence diagram with probability distributions on each event in the tree and random sampling was used to estimate resulting probability distributions for each end-state scenario. The most likely consequence of a crash is no additional hazard from the hydrogen fuel (98.1–99.9% probability) beyond the existing hazards in a vehicle crash, although some factors need additional data and study to validate. These scenarios include minor crashes with no release or ignition of hydrogen. When the hydrogen does ignite, it is most likely a jet flame from the pressure relief device release due to a hydrocarbon fire (0.03–1.8% probability). This work represents a detailed assessment of the state-of-knowledge of the likelihood associated with various vehicle crash scenarios. This is used in an event sequence framework with uncertainty propagation to estimate uncertainty around the probability of each scenario occurring.

An integrated quantitative-qualitative study to monitor the utilization and assess the perception of hydrogen fueling stations

Zero-emission vehicle (ZEV) adoption is one of the critical solutions to decarbonize the transportation sector. Among the ZEV fleet in the US, battery electric vehicles (BEV) have been leading the market penetration. However, hydrogen fuel cell electric vehicles (FCEV) have also been increasingly adopted in recent years. Although both technologies have challenges with infrastructure, unlike BEVs that have multiple venues for charging (home, work or public), FCEVs rely solely on fueling at public hydrogen stations, and their availability is a significant factor before the vehicle purchase. Therefore, for the success of FCEV adoption, a need to monitor and understand the driver satisfaction of these stations is extremely critical. This research project introduces a quantitative-qualitative approach for continuous monitoring of hydrogen stations based on the station utilization patterns and to assess their preferability based on driver experiences. To illustrate a proof-of-concept, we collected the hourly utilization data of all the hydrogen fueling stations in California for three months. The time-series data was used to develop a capacity-independent term called “Normalized Relative Utilization Index” (NRUI) that encapsulates the utilization pattern of each station to a single metric. We spatially regressed this metric over the number of FCEVs present in the neighborhood to deduce the relationship. We designed a survey to obtain the refueling experiences of FCEV drivers, where about 100 participants responded with their station preferences. Their answers were used to validate the quantitative approach and identify a “Satisfactory Utilization Range” (SUR) of stations which are preferred by most drivers. Though this project illustrates the analysis of data collected over a small period, this approach is easily scalable with new station installations and can be implemented as a continuous monitoring system with real-time station utilization data. We believe this demand-focused approach could complement the existing supply-side monitoring methods on station performance to provide a smoother fueling experience to drivers. We are also releasing the hourly station capacity dataset that was collected as a part of this study to the research community.

Measurement challenges for hydrogen vehicles

Uptake of hydrogen vehicles is an ideal solution for countries that face challenging targets for carbon dioxide reduction. The advantage of hydrogen fuel cell electric vehicles is that they behave in a very similar way to petrol engines yet they do not emit any carbon containing products during operation. The hydrogen industry currently faces the dilemma that they must meet certain measurement requirements (set by European legislation) but cannot do so due to a lack of available methods and standards. This paper outlines the four biggest measurement challenges that are faced by the hydrogen industry including flow metering, quality assurance, quality control and sampling.

Hydrogen decompression analysis by multi-stage Tesla valves for hydrogen fuel cell

Abstract Hydrogen fuel cell is an ideal power source for electric vehicles. For a hydrogen fuel cell electric vehicle, the hydrogen is reserved in a high pressure level to promote the recharge mileage while relatively low-pressure hydrogen is demanded for proper functioning of the fuel cell stack, so that decompression of hydrogen is needed before hydrogen flowing into the fuel cell. With a reverse flow through Tesla valves, there appears a large pressure drop between the inlet and outlet, which can be used for hydrogen decompression nicely. However, a single-stage Tesla valve cannot meet the pressure drop requirement, so multi-stage Tesla valves are utilized. In this paper, numerical simulations of reversed hydrogen flow through multi-stage Tesla valves are carried out. The stage number of multi-stage Tesla valves and the inlet/outlet pressure ratio are both studied, and the distributions of temperature, pressure, and velocity inside multi-stage Tesla valves are all investigated. Results show that as the stage number increases or the inlet/outlet pressure ratio decreases, the pressure and the velocity inside multi-stage Tesla valves decrease, and the less the stage number, the more possibility for the velocity higher than local acoustic speed. Besides, a power-law relationship between the flow rate, the stage number and pressure ratio is summarized.

Environmental impacts and behavioral drivers of deep decarbonization for transportation through electric vehicles

Transportation accounts for about 30% of the total greenhouse gas (GHG) emissions in the United States. To reduce GHG emissions, significant changes in the transportation fleet have been considered, with electric vehicles as one of the alternatives that could potentially reduce GHG emissions. This paper presents a comprehensive lifecycle emission and cost comparison among electric vehicles. Hybrid electric vehicles (HEV), plug in hybrid electric vehicles (PHEV), full battery electric vehicles (EVs), hydrogen fuel cell electric vehicles (FCEVs) are compared with gasoline vehicle as the base case. Since the selection among these electric vehicles depends on several factors, external costs of emission, fuel, time loss, charging time loss and maintenance cost are considered. The results show that the most environmentally benign vehicles in terms of GHG emission are FCEV and full EVs, which is approximately half of the emission by Internal combustion Engine (ICE) vehicles. The results also show that both FCVs and EVs have better air quality related emission reduction compared to ICE vehicle which results in approximately accounts for 84% reduction. The lifecycle cost results show that HEVs have the lowest lifecycle cost among all the selected vehicles, with the cost of $0.38 per mile. In addition, the effect of Carbon damage cost on total lifecycle cost is investigated. The results show that an increase in Carbon damage cost results in the penetration of HEVs and EVs to the market share.

Well-to-wheel environmental implications of fuel economy targets for hydrogen fuel cell electric buses in the United States

Hydrogen fuel cell electric vehicle technology is emerging as a promising option for the electrification of school or transit buses. For fuel cell electric transit buses, the U.S. government has set the fuel economy target at 8 miles per diesel gallon equivalent (MPDGE). However, life-cycle environmental implications of the 8 MPDGE target are currently lacking in the literature. In addition, no comparable target exists for fuel cell electric school buses.This study shows that achieving the fuel economy target (8 MPDGE) for fuel cell electric transit buses is likely to result in reductions of overall energy consumption and air emissions on a well-to-wheel basis, in comparison with diesel buses. For fuel cell electric school buses, 13 MPDGE fuel economy is expected to bring comparable benefits to those of their transit bus counterparts, in terms of well-to-wheel energy use and air emissions reductions.When it comes to the life-cycle environmental performance of fuel cell electric school/transit buses, it is critical to acknowledge that results can vary significantly depending on duty cycles, geographical factors, hydrogen fuel production pathways, and regional electric grids. All of these factors introduce nested (multilayered) variations in comparisons of diesel and fuel cell electric buses.

Two new control strategies: For hydrogen fuel saving and extend the life cycle in the hydrogen fuel cell vehicles

With the acceleration of the development process of hydrogen fuel cell electric vehicles (HFCEV), it has become very important to maximize the energy stored in the vehicle and to use the vehicle with high efficiency. This paper puts forward how to cooperate with a proton exchange membrane fuel cell (PEMFC) as the primary energy source, a lithium-ion battery (LiB) and a supercapacitor (SCAP) as the energy storage technology. Furthermore, this paper examines the effect of two new control strategies developed for HFCEV in different road models on the vehicle fuel economy and life cycle of the system components. Both control strategies applied to the system can be easily applied to the different HFCEVs with minor changes due to the simplicity of their structure and parameters. The simulation results of the study have indicated that the impact of control strategies created in different road conditions on the power of energy sources, the life cycle of system components, system efficiency and fuel economy parameters of HFCEV.

Overview of the next quarter century vision of hydrogen fuel cell electric vehicles

Last three decades, costumers and manufacturers of automotive sector have been influenced positively by Hydrogen and fuel cells (FCs). The main goal of automakers can be pointed as minimizing the fuel consumption and exhaust emissions while improving the range limits, energy efficiency and latest technology adaptation. Therewithal, electric assisted propulsion systems added to vehicles and are called as electric vehicles (EVs). For that matter, Battery Electric Vehicles (BEVs) and hydrogen Fuel Cell Electric Vehicles (FCEVs) have become the focus of researchers and producers. In this mini foreseen review, overview of the next quarter century vision of FCEVs are expressed and discussed by the helped of previous researches and with future forecast reports. The introduction part is summarized the general approach and future expectations of FCs in detailed. Technical overview is represented for FCs and FCEVs in terms of current state of technology to foreseen expectancy. Infrastructure analysis and future aspects overview part is also discussed for sector's perspective on FCEVs. The near future perspective of the FCEVs, which is seen as the next step in EVs, is discussed in detail in the next quarter century vision. Authors concluded that, between the 2030s-2050s, hydrogen FCEVs will continue their rising demand scale under the circumstances of decreasing expensive technology; enhanced energy optimization; extended range limits and increasing hydrogen refueling stations.

AWARE-US: Quantifying water stress impacts of energy systems in the United States

Energy production typically consumes a large amount of fresh water, which is a critical resource for both human and ecosystem needs. Robust water impact analysis is prudent prior to deploying new energy systems at scale. While there are many water indices representing relative water availability (or scarcity), they are not suitable for analyzing the impact of consumptive water in the context of life-cycle analysis (LCA). The available water remaining (AWARE) concept, developed by the Water Use in LCA Group, enables global water impact analysis (AWARE-Global). However, while AWARE-Global enables consistent comparison internationally, it lacks the high spatial resolution and fidelity needed for decision-making at the local level regarding energy system deployment within the United States (U.S.). In this study, we developed an AWARE system for applications in the contiguous U.S. (AWARE-US) by incorporating measured runoff and human water use data at U.S. county-level resolution. Results of AWARE-US quantify the water stress and the impacts of increase in water consumption in various regions within the U.S. To demonstrate the potential use of AWARE-US, we evaluated the impacts of a potential hydrogen fuel cell electric vehicle deployment scenario on the regional water stress in various regions within the U.S.

Direct hydrogen fuel cell electric vehicle cost analysis: System and high-volume manufacturing description, validation, and outlook

Direct hydrogen fuel cell electric vehicles (FCEVs) produce only water as a byproduct, thereby eliminating tailpipe carbon and criteria air pollutant emissions associated with internal combustion engine vehicles (ICEVs). However, in order to achieve economic parity with ICEVs, technological challenges must be overcome to lower system cost. The U.S. Department of Energy (DOE) monitors estimated fuel cell (FC) system cost and tracks progress towards milestones by techno-economic analysis based on demonstrated laboratory technologies for a next-generation 80 kWnet automotive FC stack for light-duty vehicles. The findings of the 2017 automotive FC system cost analysis are summarized, including the baseline system characteristics and specifications and the results of Design for Manufacture and Assembly (DFMA®) analysis of system manufacturing across a range of annual production rates. The highest volume predictions, for 100,000 and 500,000 units per year, result in a total system cost of $50/kWnet and $45/kWnet, respectively. The assumptions and methodology of the DFMA® analysis of the 2017 baseline FC system were validated by comparison with the FC system in the commercially available Toyota Mirai. One prospective pathway for decreasing system cost to $30/kWnet needed for cost competitiveness with ICEVs is outlined.

(Invited) Hydrogen Fuel Cell Systems in Nordic Regions

The Nordic Hydrogen Corridor (NHC) project was launched in 2016 to introduce new Hydrogen Refueling Stations (HRS), hydrogen production units (electrolysers) and Fuel Cell Electric Vehicles (FCEV) along the Trans-European Transport (TENT-T) Network in Sweden in the period 2017-2020. This HRS network will enable zero emission transport facilities between the capital of the Nordic countries from Norway through Sweden to Denmark and Finland and further via Germany to the rest of the Europe [1]. In the case of Norway, the country’s strategy is structured around five closely interrelated themes addressing: (i) energy supply security, (ii) a fully-integrated energy market, (iii) energy efficiency, (iv) decarbonising the economy and (v) research, innovation and competitiveness. Climate change is one of the policy priorities of Norway. The country is a heavy producer of renewable energy and electricity generation, with hydropower being the source of most of the production [2]. For example, in 2013 Norway produced circa 134 TWh of electricity from which 96%, 1.5% and 2.5% was generated from hydropower, wind power and thermal power, respectively [2]. There is also a large potential in wind power, offshore wind power and wave power, as well as the production of bio-energy from biomass. Although, Norway has limited resources in solar energy, it is one of the world's largest producers of solar grade silicon and silicon solar cells. Hydrogen Energy has been identified by Norway as an alternative fuel with the potential for a substantial contribution to reduce petroleum dependence and greenhouse gases emissions in the long term. The Norwegian government supports the potential role of hydrogen for Norway in the transition to a zero-emission society [3,4]. In line with the EU, Hydrogen and Fuel Cell Technologies (HFCTs) have been identified as a key area of research priority for Norway [3-5]. For example, the White Paper on Norway’s energy policy [4] explicitly describes the national hydrogen priorities, which focus on research and development within production, storage and use of hydrogen. Indeed, among the renewable energy sources, HFCTs are considered as a key technology of the 21st century, not only because of its high efficiency in heat and electricity generation, but also because of its potential role in attaining sustainable energy system. It is also envisaged that HFCT will be integrated into “intelligent” energy networks, with conventional and distributed renewable electricity systems. Also, they enable flexible and adaptable fueling strategies, according to local resources, with fossil, bio-fuels or synthetic fuels to reduce impact on air pollution and climate change. For a few years, Norway has put significant effort in HFCT R&D through national and international projects as well as in implementing a hydrogen infrastructure. This presentation highlights the main HFCT projects in Norway along with the other Nordic countries.

Hydrogen fuel cell electric vehicle performance and user-response assessment: Results of an extended driver study

This study examined driver acceptance and performance of hydrogen fuel cell electric vehicles as tested in real-world conditions over a two-year period. The study sample was a volunteer group of “n = 54” drivers who drove the vehicle for a month-long trial period. Each driver took ‘before’ and ‘after’ surveys regarding their driving experience. Drivers drove an average of 1400 miles per month, and either witnessed and/or performed vehicle refueling 3–10 times during their test period.Key findings from the study include that: 1) 80% of study participant drivers found that the fuel cell vehicle (FCV) performance “exceeded” or “greatly exceeded” their expectations; 2) 98% of study participant drivers view hydrogen as a fuel for vehicles as being “as safe” or “safer” than gasoline as a fuel for vehicles; and 3) 94% of participants view the process of fueling a vehicle with hydrogen to be “as safe” or “safer” than gasoline fueling. Other findings include that 85% of study participants who performed their own fueling described hydrogen fueling to be “somewhat” or “very” simple. Of the participants, 62% percent had to forgo at least one trip due to lack of hydrogen fuel, although vehicle range was rated by 75% of participants as entirely or mostly adequate. If fueling infrastructure availability was not an issue, and fuel cost per-mile was at parity with gasoline, 75% of participants would be willing to pay $40,000 or less for an FCV.

Life-cycle implications of hydrogen fuel cell electric vehicle technology for medium- and heavy-duty trucks

This study provides a comprehensive and up-to-date life-cycle comparison of hydrogen fuel cell electric trucks (FCETs) and their conventional diesel counterparts in terms of energy use and air emissions, based on the ensemble of well-established methods, high-fidelity vehicle dynamic simulations, and real-world vehicle test data. For the centralized steam methane reforming (SMR) pathway, hydrogen FCETs reduce life-cycle or well-to-wheel (WTW) petroleum energy use by more than 98% compared to their diesel counterparts. The reduction in WTW air emissions for gaseous hydrogen (G.H2) FCETs ranges from 20 to 45% for greenhouse gases, 37–65% for VOC, 49–77% for CO, 62–83% for NOx, 19–43% for PM10, and 27–44% for PM2.5, depending on vehicle weight classes and truck types. With the current U.S. average electricity generation mix, FCETs tend to create more WTW SOx emissions than their diesel counterparts, mainly because of the upstream emissions related to electricity use for hydrogen compression/liquefaction. Compared to G.H2, liquid hydrogen (L.H2) FCETs generally provide smaller WTW emissions reductions. For both G.H2 and L.H2 pathways for FCETs, because of electricity consumption for compression and liquefaction, spatio-temporal variations of electricity generation can affect the WTW results. FCETs retain the WTW emission reduction benefits, even when considering aggressive diesel engine efficiency improvement.

ZEFER project to demonstrate benefits of FCEV urban fleets

The Zero Emission Fleet vehicles for European Roll-out (ZEFER) project will deploy a total of 180 hydrogen fuel cell electric vehicles in three European capitals, with fleets of 60 vehicles each in London, Paris and Brussels. These vehicles will be used in high-mileage urban fleets such as taxis, private-hire vehicles, and police cars.

UK funding to boost refueling infrastructure and nearly 200 FCEVs

In the UK, a consortium including ITM Power, Shell, Toyota, Honda and Hyundai has won £8.8 million (US$12.6 million) in funding from the Department for Transport (DfT), to improve access to an expanded network of hydrogen refueling stations to support the continued rollout of hydrogen fuel cell electric vehicles in the UK. Police cars and taxis will be among nearly 200 new hydrogen vehicles to be deployed alongside new and upgraded hydrogen stations.

Parametric study on Tesla valve with reverse flow for hydrogen decompression

Recharge mileage is of great importance for a hydrogen fuel cell electric vehicle. High pressure hydrogen storage can increase the recharge mileage significantly. Before hydrogen flows into the fuel cell, a decompression process is necessary. To overcome the seal of the piping system and realize the decompression, Tesla valve can be well used, since it is a type of check valve without moving parts, and when there is a reverse flow, large pressure drop appears between the inlet and outlet. In order to obtain a better pressure drop performance for a Tesla valve, in this paper, the structural parameters including the hydraulic diameter, the valve angle, and the inner curve radius are investigated for a large range of inlet velocities. The results indicate that a small hydraulic diameter and small inner curve radius but large valve angle can provide a higher pressure drop under a large inlet velocity, while the pressure drop under different structural parameters barely changes under a small inlet velocity (less than 100 m/s). Besides, there is a low-pressure zone behind the outlet of the bend channel, which should be paid attention. This work can be referred by the further applications of Tesla valves in hydrogen fuel cell electric vehicles for hydrogen decompression.

Integrating a hydrogen fuel cell electric vehicle with vehicle-to-grid technology, photovoltaic power and a residential building

This paper presents the results of a demonstration project, including building-integrated photovoltaic (BIPV) solar panels, a residential building and a hydrogen fuel cell electric vehicle (FCEV) for combined mobility and power generation, aiming to achieve a net zero-energy residential building target. The experiment was conducted as part of the Car as Power Plant project at The Green Village in the Netherlands. The main objective was to assess the end-user’s potential of implementing FCEVs in vehicle-to-grid operation (FCEV2G) to act as a local energy source. FCEV2G field test performance with a Hyundai ix35 FCEV are presented. The car was adapted using a power output socket capable of delivering up to 10 kW direct current (DC) to the alternating current (AC) national grid when parked, via an off-board (grid-tie) inverter. A Tank-To-AC-Grid efficiency (analogous to Tank-To-Wheel efficiency when driving) of 44% (measured on a Higher Heating Value basis) was obtained when the car was operating in vehicle-to-grid (V2G) mode at the maximum power output. By collecting and analysing real data on the FCEV power production in V2G mode, and on BIPV production and household consumption, two different operating modes for the FCEV offering balanced services to a residential microgrid were identified, namely fixed power output and load following.Based on the data collected, one-year simulations of a microgrid consisting of 10 all-electric dwellings and 5 cars with the different FCEV2G modes of operation were performed. Simulation results were evaluated on the factors of autonomy, self-consumption of locally produced energy and net-energy consumption by implementing different energy indicators. The results show that utilizing an FCEV working in V2G mode can reduce the annual imported electricity from the grid by approximately 71% over one year, and aiding the buildings in the microgrid to achieve a net zero-energy building target. Furthermore, the simulation results show that utilizing the FCEV2G setup in both modes analysed, could be economically beneficial for the end-user if hydrogen prices at the pump fall below 8.24 €/kg.

Current and Future United States Light-Duty Vehicle Pathways: Cradle-to-Grave Lifecycle Greenhouse Gas Emissions and Economic Assessment.

This article presents a cradle-to-grave (C2G) assessment of greenhouse gas (GHG) emissions and costs for current (2015) and future (2025-2030) light-duty vehicles. The analysis addressed both fuel cycle and vehicle manufacturing cycle for the following vehicle types: gasoline and diesel internal combustion engine vehicles (ICEVs), flex fuel vehicles, compressed natural gas (CNG) vehicles, hybrid electric vehicles (HEVs), hydrogen fuel cell electric vehicles (FCEVs), battery electric vehicles (BEVs), and plug-in hybrid electric vehicles (PHEVs). Gasoline ICEVs using current technology have C2G emissions of ∼450 gCO2e/mi (grams of carbon dioxide equivalents per mile), while C2G emissions from HEVs, PHEVs, H2 FCEVs, and BEVs range from 300-350 gCO2e/mi. Future vehicle efficiency gains are expected to reduce emissions to ∼350 gCO2/mi for ICEVs and ∼250 gCO2e/mi for HEVs, PHEVs, FCEVs, and BEVs. Utilizing low-carbon fuel pathways yields GHG reductions more than double those achieved by vehicle efficiency gains alone. Levelized costs of driving (LCDs) are in the range $0.25-$1.00/mi depending on time frame and vehicle-fuel technology. In all cases, vehicle cost represents the major (60-90%) contribution to LCDs. Currently, HEV and PHEV petroleum-fueled vehicles provide the most attractive cost in terms of avoided carbon emissions, although they offer lower potential GHG reductions. The ranges of LCD and cost of avoided carbon are narrower for the future technology pathways, reflecting the expected economic competitiveness of these alternative vehicles and fuels.