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.     

Lifecycle performance assessment of fuel cell/battery electric vehicles

This paper has performed an assessment of lifecycle (as known as well-to-wheels, WTW) greenhouse gas (GHG) emissions and energy consumption of a fuel cell vehicle (FCV). The simulation tool MATLAB/Simulink is employed to examine the real-time behaviors of an FCV, which are used to determine the energy efficiency and the fuel economy of the FCV. Then, the GREET (Greenhouse gases, Regulated Emissions, and Energy use in Transportation) model is used to analyze the fuel-cycle energy consumption and GHG emissions for hydrogen fuels. Three potential pathways of hydrogen production for FCV application are examined, namely, steam reforming of natural gas, water electrolysis using grid electricity, and water electrolysis using photovoltaic (PV) electricity, respectively. Results show that the FCV has the maximum system efficiency of 60%, which occurs at about 25% of the maximum net system power. In addition, the FCVs fueled with PV electrolysis hydrogen could reduce about 99.2% energy consumption and 46.6% GHG emissions as compared to the conventional gasoline vehicles (GVs). However, the lifecycle energy consumption and GHG emissions of the FCVs fueled with grid-electrolysis hydrogen are 35% and 52.8% respectively higher than those of the conventional GVs. As compared to the grid-based battery electric vehicles (BEVs), the FCVs fueled with reforming hydrogen from natural gas are about 79.0% and 66.4% in the lifecycle energy consumption and GHG emissions, respectively.     

Greenhouse gas implications of using coal for transportation: Life cycle assessment of coal-to-liquids,plug-in hybrids,and hydrogen pathways

Using coal to produce transportation fuels could improve the energy security of the United States by replacing some of the demand for imported petroleum. Because of concerns regarding climate change and the high greenhouse gas (GHG) emissions associated with conventional coal use, policies to encourage pathways that utilize coal for transportation should seek to reduce GHGs compared to petroleum fuels. This paper compares the GHG emissions of coal-to-liquid (CTL) fuels to the emissions of plug-in hybrid electric vehicles (PHEV) powered with coal-based electricity, and to the emissions of a fuel cell vehicle (FCV) that uses coal-based hydrogen. A life cycle approach is used to account for fuel cycle and use-phase emissions, as well as vehicle cycle and battery manufacturing emissions. This analysis allows policymakers to better identify benefits or disadvantages of an energy future that includes coal as a transportation fuel. We find that PHEVs could reduce vehicle life cycle GHG emissions by up to about one-half when coal with carbon capture and sequestration is used to generate the electricity used by the vehicles. On the other hand, CTL fuels and coal-based hydrogen would likely lead to significantly increased emissions compared to PHEVs and conventional vehicles using petroleum-based fuels.     

Deployment of fuel cell vehicles in China: Greenhouse gas emission reductions from converting the heavy-duty truck fleet from diesel and natural gas to hydrogen

Hydrogen fuel cells, as an energy source for heavy duty vehicles, are gaining attention as a potential carbon mitigation strategy. Here we calculate the greenhouse gas (GHG) emissions of the Chinese heavy-duty truck fleet under four hydrogen fuel cell heavy-duty truck penetration scenarios from 2020 through 2050. We introduce Aggressive, Moderate, Conservative and No Fuel Cell Vehicle (No FCV) scenarios. Under these four scenarios, the market share of heavy-duty trucks powered by fuel cells will reach 100%, 50%, 20% and 0%, respectively, in 2050. We go beyond previous studies which compared differences in GHG emissions from different hydrogen production pathways. We now combine an analysis of the carbon intensity of various hydrogen production pathways with predictions of the future hydrogen supply structure in China along with various penetration rates of heavy-duty fuel cell vehicles. We calculate the associated carbon intensity per vehicle kilometer travelled of the hydrogen used in heavy-duty trucks in each scenario, providing a practical application of our research. Our results indicate that if China relies only on fuel economy improvements, with the projected increase in vehicle miles travelled, the GHG emissions of the heavy-duty truck fleet will continue to increase and will remain almost unchanged after 2025. The Aggressive, Moderate and Conservative FCV Scenarios will achieve 63%, 30% and 12% reductions, respectively, in GHG emissions in 2050 from the heavy duty truck fleet compared to the No FCV Scenario. Additional reductions are possible if the current source of hydrogen from fossil fuels was displaced with increased use of hydrogen from water electrolysis using non-fossil generated electricity.     

Realistic simulation of fuel economy and life cycle metrics for hydrogen fuel cell vehicles

The present work contributes an engineered life cycle assessment (LCA) of hydrogen fuel cell passenger vehicles based on a real‐world driving cycle for semi‐urban driving conditions. A new customized LCA tool is developed for the comparison of conventional gasoline and hydrogen fuel cell vehicles (FCVs), which utilizes a dynamic vehicle simulation approach to calculate realistic, fundamental science based fuel economy data from actual drive cycles, vehicle specifications, road grade, engine performance, fuel cell degradation effects, and regenerative braking. The total greenhouse gas (GHG) emission and life cycle cost of the vehicles are compared for the case of hydrogen production by electrolysis in British Columbia, Canada. A 72% reduction in total GHG emission is obtained for switching from gasoline vehicles to FCVs. While fuel cell performance degradation causes 7% and 3% increases in lifetime fuel consumption and GHG emission, respectively, regenerative braking improves the fuel economy by 23% and reduces the total GHG emission by 10%. The cost assessment results indicate that the current FCV technology is approximately $2,100 more costly than the equivalent gasoline vehicle based on the total lifetime cost including purchase and fuel cost. However, prospective enhancements in fuel cell durability could potentially reduce the FCV lifetime cost below that of gasoline vehicles. Overall, the present results indicate that fuel cell vehicles are becoming both technologically and economically viable compared with incumbent vehicles, and provide a realistic option for deep reductions in emissions from transportation. Copyright © 2016 John Wiley & Sons, Ltd.     

An emission analysis study of hydrogen powered vehicles

In this study, emissions of internal combustion engine, hybrid, and fuel cell vehicles have been investigated when they use hydrogen in gas or liquid form. Well to pump (WTP) and well to wheel (WTW) emissions of volatile organic compounds (VOC), carbon monoxide (CO), nitrogen oxides (NO_x), particulate matters (PM₁₀ and PM_2.5), sulphur oxides (SO_x), and carbon dioxide (CO₂) emitted from vehicles are compared for scenarios in 2010, 2020, 2030, 2040, and 2050 years. For these years, 2005, 2015, 2025, 2035, and 2045 vehicle technologies are used in the analyses. In total emissions, gaseous hydrogen (GH₂) powered fuel cell vehicles (FCV) appear to be the best options, while liquid hydrogen (LH₂) powered spark ignition internal combustion engine vehicles (SI ICEV) are the worst. The lowest and highest CO₂ emission values are seen as 81 g/km and 416 g/km in GH₂ powered FCVs in 2050 and LH₂ powered SI ICEVs in 2010, respectively.     

Dynamic simulation and lifecycle assessment of hydrogen fuel cell electric vehicles considering various hydrogen production methods

In this research study, a real model of a hydrogen fuel cell vehicle is simulated using Simcenter Amesim software. The software used for vehicle simulation enabled dynamic simulation, resulting in more precise simulation. Furthermore, considering that fuel cell degradation is one of the significant challenges confronting fuel cell vehicle manufacturers, we examined the impact of fuel cell degradation on the performance of hydrogen vehicles. According to the findings, a hydrogen vehicle with a degraded fuel cell consumes 14.3% more fuel than a fresh fuel cell hydrogen vehicle. A comprehensive life cycle assessment (LCA) is also performed for the designed hydrogen vehicle. The results of the hydrogen vehicle life cycle assessment are compared with a gasoline vehicle to fully understand the effect of hydrogen vehicles in reducing air emissions. The methods considered for hydrogen production included natural gas reforming, electrolysis, and thermochemical water splitting method. Furthermore, because the source of electricity used for electrolysis has a significant impact on the life cycle emission of a hydrogen vehicle, three different power sources were considered in this assessment. Finally, while a hydrogen vehicle with a degraded fuel cell emits lower carbon dioxide (CO₂) than a gasoline vehicle, the emitted CO₂ from this vehicle using hydrogen from electrolysis is approximately 25% higher than that of a new hydrogen vehicle.     

Comparative life cycle assessment of hydrogen pathways from fossil sources in China

Emissions of multiple hydrogen production pathways from fossil sources were evaluated and compared with that of fossil fuel production pathways in China by using the life cycle assessment method. The considered hydrogen pathways are gasoline reforming, diesel reforming, natural gas reforming, soybean‐derived biodiesel (s‐biodiesel) reforming, and waste cooking oil‐derived biodiesel reforming. Moreover, emissions and energy consumption of fuel cell vehicles utilizing hydrogen from different fossil sources were presented and compared with those of the electric vehicle, the internal combustion engine vehicle, and the compression ignition engine vehicle. The results indicate both fuel cell vehicles and the electric vehicle have less greenhouse gas emissions and energy consumption compared with the traditional vehicle technologies in China. Based on an overall performance comparison of five different fuel cell vehicles and the electric vehicle in China, fuel cell vehicles operating on hydrogen produced from natural gas and waste cooking oil‐derived biodiesel show the best performance, whereas the electric vehicle has the worse performance than all the fuel cell vehicles because of very high share of coal in the electricity mix of China. The emissions of electric vehicle in China will be in the same level with that of natural gas fuel cell vehicle if the share of coal decreases to around 40% and the share of renewable energy increases to around 20% in the electricity mix of China. Copyright © 2016 John Wiley & Sons, Ltd.     

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.     

The impact of fuel cell vehicle deployment on road transport greenhouse gas emissions: The China case

Considerable attention has been paid to energy security and climate problems caused by road vehicle fleets. Fuel cell vehicles provide a new solution for reducing energy consumption and greenhouse gas emissions, especially those from heavy-duty trucks. Although cost may become the key issue in fuel cell vehicle development, with technological improvements and cleaner pathways for hydrogen production, fuel cell vehicles will exhibit great potential of cost reduction. In accordance with the industrial plan in China, this study introduces five scenarios to evaluate the impact of fuel cell vehicles on the road vehicle fleet greenhouse gas emissions in China. Under the most optimistic scenario, greenhouse gas emissions generated by the whole fleet will decrease by 13.9% compared with the emissions in a scenario with no fuel cell vehicles, and heavy-duty truck greenhouse gas emissions will decrease by nearly one-fifth. Greenhouse gas emissions intensity of hydrogen production will play an essential role when fuel cell vehicles' fuel cycle greenhouse gas emissions are calculated; therefore, hydrogen production pathways will be critical in the future.     

Solar methanol synthesis by clean hydrogen production from seawater on offshore artificial islands

Synthetic fuel production from renewable energy, water, and anthropogenic carbon resources offers a promising alternative to fossil fuels by reducing the consumption of nonrenewable resources and greenhouse gas emissions. This article presents a case study of a solar‐based methanol plant that derives hydrogen and carbon dioxide material inputs from seawater on an offshore artificial island. Photovoltaic cells generate electricity for an electrolytic cation exchange membrane (E‐CEM) reactor that simultaneously produces hydrogen and carbon dioxide, with freshwater for electrolysis via seawater reverse osmosis. Carbon dioxide hydrogenation in a low‐pressure isothermal cascade‐type reactor system produces methanol as a liquid fuel product. Thermodynamic assessment of the integrated system indicates solar‐to‐methanol energy and exergy conversion efficiencies of 1.5% and 1.3%, respectively, with the most significant losses occurring in the offshore concentrator photovoltaic (CPV) and E‐CEM reactor unit.     

Recycling a hydrogen rich residual stream to the power and steam plant

The benefits of using a residual hydrogen rich stream as a clean combustion fuel in order to reduce Carbon dioxide emissions and cost is quantified. A residual stream containing 86% of hydrogen, coming from the top of the demethanizer column of the cryogenic separation sector of an ethylene plant, is recycled to be mixed with natural gas and burned in the boilers of the utility plant to generate high pressure steam and power. The main advantage is due to the fact that the hydrogen rich residual gas has a higher heating value and less CO₂ combustion emissions than the natural gas. The residual gas flowrate to be recycled is selected optimally together with other continuous and binary operating variables. A Mixed Integer Non Linear Programming problem is formulated in GAMS to select the operating conditions to minimize life cycle CO₂ emissions.     

How liquid hydrogen production methods affect emissions in liquid hydrogen powered vehicles?

Emissions variations of liquid hydrogen (LH₂) production methods in liquid hydrogen powered vehicles are investigated in this study. Volatile organic compounds (VOC), carbon monoxide (CO), nitrogen oxides (NO_x), particulate matters (PM₁₀ & PM_2.5), sulfur oxides (SO_x), and carbon dioxide (CO₂) emissions, which are on well-to-wheel (WTW) basis, are evaluated for 2013 model year's cars in the target year of 2018. GREET software is utilized for the emissions. When the average values of all emissions are compared, hydrogen production by the solar power, nuclear, and electrolysis methods have the lowest emissions, respectively, and hydrogen production by coal and electricity methods have the highest emissions, respectively. On the other hand, it is found that in all emission types and hydrogen production methods, fuel cell vehicles (FCV) emit less emission than spark ignition hybrid electric vehicles (SI HEV) and SI HEVs emit less emission than spark ignition internal combustion engine vehicles (SI ICEV). Emissions decrease by 22.4% in SI HEVs compared to SI ICEVs, 35.1% in FCVs compared to SI HEVs, and 49.6% in FCVs compared to SI ICEVs for average of all emissions.     

A preliminary life cycle assessment of PEM fuel cell powered automobiles

This paper provides a preliminary life cycle assessment (LCA) of polymer electrolyte membrane (PEM) fuel cell powered automobile. Life cycle of PEM fuel cell automobile not only includes operation of the vehicle on the road but also include production and distribution of both the vehicle and the fuel (e.g. hydrogen) during the vehicle’s entire lifetime. Assessment is based on the published data available in the literature. The two characteristics of the life cycle, which were assessed, are energy consumption and greenhouse gases (GHGs) emissions. Greenhouse gases (GHGs) emissions considered in the present assessment are CO₂ and CH₄. In addition, conventional internal combustion engine (ICE) automobile is also assessed based on similar characteristics for comparison with PEM fuel cell automobile. It is found that the energy utilized to generate the hydrogen during fuel cycle for the PEM automobile is about 3.5 times higher than the energy utilized to generate the gasoline during its fuel cycle. However, the overall life cycle energy consumption of PEM fuel cell automobile is about 2.3 times less than that of ICE automobile. Similarly, the GHGs emissions of PEMFC automobile are about 8.5 times higher than ICE automobile during the fuel cycle, but the overall life cycle GHGs emissions are about 2.6 times lower than ICE automobile.     

Natural gas usage as a heat source for integrated SMR and thermochemical hydrogen production technologies

This paper investigates various usages of natural gas (NG) as an energy source for different hydrogen production technologies. A comparison is made between the different methods of hydrogen production, based on the total amount of natural gas needed to produce a specific quantity of hydrogen, carbon dioxide emissions per mole of hydrogen produced, water requirements per mole of hydrogen produced, and a cost sensitivity analysis that takes into account the fuel cost, carbon dioxide capture cost and a carbon tax. The methods examined are the copper–chlorine (Cu–Cl) thermochemical cycle, steam methane reforming (SMR) and a modified sulfur–iodine (S–I) thermochemical cycle. Also, an integrated Cu–Cl/SMR plant is examined to show the unique advantages of modifying existing SMR plants with new hydrogen production technology. The analysis shows that the thermochemical Cu–Cl cycle out-performs the other conventional methods with respect to fuel requirements, carbon dioxide emissions and total cost of production.     

Energy consumption and GHG emissions of GTL fuel by LCA: Results from eight demonstration transit buses in Beijing

Gas-to-liquids (GTL) as an alternative to diesel is considered to be one of the technical options to reduce petroleum consumption in the on-road transportation sector. Between May and August 2007, a joint demonstration program by Tsinghua University, Beijing Transit, Cummins Corporation and Shell Corporation was carried out in Beijing. The program focused on the supply systems and vehicle use of GTL fuel. The demonstration fleet was formed by four transit buses fueled with GTL and four with diesel. It was demonstrated that GTL has good compatibility with diesel in terms of fuel supply system and vehicle use. This paper compares the energy consumption and GHG emissions of diesel and GTL fuel supply chains by life cycle analysis based on demonstration results. The results indicate GTL’s large range (reported 54–70%) in synthesis efficiency, as the key factor in determining energy consumption and GHG emissions within the GTL fuel supply chain. For the probable case (GTL synthesis efficiency: 65%), the life cycle energy consumption and GHG emissions of GTL fuel are 42.5% and 12.6% higher than that of diesel. For two sensitivity analysis cases (GTL synthesis efficiency: 54% and70%), energy consumptions are 74.2% and 31.2% higher and GHG emissions are 27.3% and 7.4% higher than that of the diesel fuel supply chain. If the efficiency of the GTL synthesis process is improved to 75%, then the GHG emissions level of the GTL fuel supply chain can be reduced to the same level as the diesel fuel supply chain.     

The estimation of fugitive gas emissions from hydrogen production by natural gas steam reforming

In recent years, a significant amount of interest has been directed towards using hydrogen as an alternative source of energy to fossil fuel. Even though hydrogen is emission free in its end use; the production of hydrogen itself requires energy and may cause process emissions including fugitive emissions from various sources, mainly the piping equipment and fittings. The emissions, even though not as large as stack emissions, they may still pose risks to the environment and health especially to the workers within the plant area. This paper presents the estimation of fugitive emissions from hydrogen production process via natural gas steam reforming. Firstly, the natural gas steam reforming process was simulated before the fugitive emissions of carbon monoxide (CO) and greenhouse gases (GHGs), such as methane (CH₄) and carbon dioxide (CO₂) in the process were estimated. Then, the consequent global warming potential (GWP) and the associated health risks due to the emissions were evaluated. A comparison of the GHG fugitive emissions with other sources of GHG emissions over the hydrogen production life cycle was also performed. Methane (CH₄) recorded the highest rate of fugitive emissions contributing to the greatest GWP. On the other hand, CO₂ represented the total stack emissions contributing to 100% of the total GWP. The concentrations of the gases emitted as fugitive emissions (CH₄, CO₂ and CO) in the process area are below the threshold exposure limit indicating that the plant environment is safe for workers daily exposures to the emitted gases.     

Long-term implications of alternative light-duty vehicle technologies for global greenhouse gas emissions and primary energy demands

This study assesses global light-duty vehicle (LDV) transport in the upcoming century, and the implications of vehicle technology advancement and fuel-switching on greenhouse gas emissions and primary energy demands. Five different vehicle technology scenarios are analyzed with and without a CO₂ emissions mitigation policy using the GCAM integrated assessment model: a reference internal combustion engine vehicle scenario, an advanced internal combustion engine vehicle scenario, and three alternative fuel vehicle scenarios in which all LDVs are switched to natural gas, electricity, or hydrogen by 2050. The emissions mitigation policy is a global CO₂ emissions price pathway that achieves 450 ppmv CO₂ at the end of the century with reference vehicle technologies. The scenarios demonstrate considerable emissions mitigation potential from LDV technology; with and without emissions pricing, global CO₂ concentrations in 2095 are reduced about 10 ppmv by advanced ICEV technologies and natural gas vehicles, and 25 ppmv by electric or hydrogen vehicles. All technological advances in vehicles are important for reducing the oil demands of LDV transport and their corresponding CO₂ emissions. Among advanced and alternative vehicle technologies, electricity- and hydrogen-powered vehicles are especially valuable for reducing whole-system emissions and total primary energy.     

Fuel conservation and GHG (Greenhouse gas) emissions mitigation scenarios for China’s passenger vehicle fleet

Passenger vehicles are the main consumers of gasoline in China. We established a bottom-up model which focuses on the simulation of energy consumptions and greenhouse gas (GHG) emissions growth by China’s passenger vehicle fleet. The fuel conservation and GHG emissions mitigation effects of five measures including constraining vehicle registration, reducing vehicle travel, strengthening fuel consumption rate (FCR) limits, vehicle downsizing and promoting electric vehicle (EV) penetration were evaluated. Based on the combination of these measures, the fuel conservation and GHG emissions mitigation scenarios for China’s passenger vehicle fleet were analyzed. Under reference scenario with no measures implemented, the fuel consumptions and life cycle GHG emissions will reach 520 million tons of oil equivalent (Mtoe) and 2.15 billion tons in 2050, about 8.1 times the level in 2010. However, substantial fuel conservation can be achieved by implementing the measures. By implementing all five measures together, the fuel consumption will reach 138 Mtoe in 2030 and decrease to 126 Mtoe in 2050, which is only 37.1% and 24.3% of the consumption under reference scenario. Similar potential lies in GHG mitigation. The results and scenarios provided references for the Chinese government’s policy-making.     

Modeling operating modes,energy consumptions,and infrastructure requirements of fuel cell plug in hybrid electric vehicles using longitudinal geographical transportation data

The fuel cell plug in hybrid electric vehicle (FCPHEV) is a near-term realizable concept to commercialize hydrogen fuel cell vehicles (FCV). Relative to conventional FCVs, FCPHEVs seek to achieve fuel economy benefits through the displacement of hydrogen energy with grid-sourced electrical energy, and they may have less dependence on a sparse hydrogen fueling infrastructure. Through the simulation of almost 690,000 FCPHEV trips using geographic information system (GIS) data surveyed from a fleet of private vehicles in the Puget Sound area of Washington State, USA, this study derives the electrical and hydrogen energy consumption of various design and control variants of FCPHEVs. Results demonstrate that FCPHEVs can realize hydrogen fuel consumption reductions relative to conventional FCV technologies, and that the fuel consumption reductions increase with increased charge depleting range. In addition, this study quantifies the degree to which FCPHEVs are less dependent on hydrogen fueling infrastructure, as FCPHEVs can refuel with hydrogen at a lower rate than FCVs. Reductions in hydrogen refueling infrastructure dependence vary with control strategies and vehicle charge depleting range, but reductions in fleet-level refueling events of 93% can be realized for FCPHEVs with 40 miles (60 km) of charge depleting range. These fueling events occur on or near the network of highways at approximately 4% of the rate (refuelings per year) of that for conventional FCVs. These results demonstrate that FCPHEVs are a type of FCV that can enable an effective and concentrated hydrogen refueling network.