Driving a hydrogen fuel cell vehicle (HFCV) is similar to driving an electric car; the only significant difference lies in that HFCVs contain one or more armored tanks filled with pure hydrogen under extreme pressure.
Hydrogen passes through a fuel cell stack to produce electricity which powers electric motors that turn the wheels of the car, recapturing braking energy while providing additional power during acceleration.
Fuel Cell Technology
Hydrogen fuel cells use hydrogen and oxygen to generate electrical energy to power vehicles, providing zero emission mobility solutions with cost-effective power sources that compare favorably to electric batteries in conventional cars. Fuel cell technology enjoys wide industrial, political and media support as a recognized solution. Fuel cells offer efficient power delivery compared to batteries in traditional cars.
Fuel cells can be run on hydrogen generated from renewable resources like solar or wind power or fossil fuels such as natural gas. Furthermore, local production facilities near vehicle destinations can produce this energy source locally to save logistics costs and increase convenience for drivers.
Fuel cells combine hydrogen (H2) and oxygen (O2) through an electrochemical reaction to produce electricity, heat, and water vapor – energy which can then be used to power a car’s motors or stored as range extender fuel in its tank to extend driving range.
Hydrogen fuel cells are compact and quiet electric power plants that produce no harmful emissions, leaving only water vapor and heat as byproducts – an enormous improvement from gasoline or diesel vehicles, which emit nitrogen oxides, hydrocarbons and particulate matter into the environment.
Research indicates that fuel cells are more energy-efficient than internal combustion engines, converting more of their chemical potential to useful power and using less raw material than batteries – making them more sustainable and eco-friendly than their counterparts.
Today’s automakers are increasingly offering fuel cell vehicles. Toyota currently leads this space with their Mirai family car which has sold more than 5,000 units in the U.S. Meanwhile Renault provides their Master Van H2-TECH which boasts both an onboard hydrogen storage system and fuel cell to extend driving range by an estimated 400 km (WLTC* cycle).
To ensure widespread accessibility of fuel cell vehicles, stakeholders are working on creating the infrastructure necessary for them. One such initiative is H2USA – a public-private partnership comprised of the Department of Energy’s Hydrogen and Fuel Cell Technologies Office, automakers, state governments and other organizations – that helps coordinate research on cost-effective hydrogen production and distribution solutions that could bring FCVs to a variety of customers from passenger cars to commercial trucks.
Fuel cell vehicles rely on their fuel cell stack as the core component, converting hydrogen to electricity for use by an electric motor. But the system also features a fuel tank, power electronics controller and thermal management system; all working together to keep everything operating as intended.
Hydrogen is stored in special tanks onboard the vehicle and fed into its fuel cell stack, where it reacts with dioxygen (O2) from the air to generate electricity, water vapor and heat that are then used to drive its electric motor – producing zero local emissions while creating an experience similar to that of an EV.
Fuel cell vehicles must be refueled similarly to any conventional car. However, special care must be taken with regard to their tanks, fuel-cell stack and plumbing – hydrogen gas being highly flammable necessitates armoured and pressurized tanks that must prevent leaks before being filled at hydrogen stations around the United States and elsewhere.
Fuel cells have seen considerable advancement in research, leading to decreased costs and improved tank designs that bring them closer to more consumers. Renault unveiled their first mass-production vehicle using fuel cell technology – the Renault Master Van H2-Tech with four hydrogen tanks allowing for 400 km range!
These tanks are constructed from carbon-fiber-coated metal with a composite overwrap, designed to keep hydrogen at optimal pressure without losing energy or becoming exposed to elements. As well as cutting manufacturing costs, advances in materials allow smaller and more compact tanks that provide high storage capacities of hydrogen.
Fuel cell systems have seen great improvements recently, reducing size, weight and energy density for greater appeal among drivers. Indeed, many major automakers that specialize in electric cars are also creating fuel cell vehicles like Toyota’s Mirai with an impressive 500+ km range.
Hydrogen fuel cell vehicles are designed to refuel as easily and rapidly as conventional cars. At hydrogen refueling stations, pressurized hydrogen can be added at pressurized pressure levels within less than 10 minutes; due to producing zero emissions when driving, filling your car this way is very quick and clean; making refueling convenient for long distance drivers or those without access to plug-in power outlets at home.
Hydrogen used to power FCEVs comes from multiple sources. Most often it is produced using electricity generated using renewable resources like solar, wind, or hydroelectricity; but it can also come from water resources, plant materials or landfill gas; even some pilot projects use trash as an energy source to produce hydrogen!
Though consumer hydrogen stations remain scarce at present, efforts are underway to expand them. Unlike plug-in electric vehicles that charge from the grid, hydrogen vehicles need to be replenished with hydrogen from dedicated stations. Refueling an EV involves plugging it in for recharge; with hydrogen vehicles you connect directly to a dispenser with an attached hose and let the station fill your tank up instead.
Refueling station reliability is of great concern to early FCEV adopters. While global deployment of just 200 or so stations remains modest, these fueling networks have proven more vulnerable than anticipated and experienced frequent outages and delays than anticipated – frustrating drivers who invested money in an unknown fueling future.
Recent improvements have helped most owners alleviate some of their frustration. Where previously it was common to find empty hydrogen tanks at existing stations, now its availability has significantly increased.
Refueling infrastructure for heavy-duty FCEVs such as line-haul trucks and material handling equipment is expanding. Larger fleets will require multiple fueling locations; however, mobile hydrogen fuelers can provide hydrogen to an entire fleet in one convenient spot.
People often assume fuel cell vehicles require complex and costly maintenance, yet the opposite is actually true. Fuel cells themselves don’t require much in terms of maintenance aside from periodic inspections to check for leaks or other forms of damage, while electric motors and other components comprising their powertrain do require regular replacements, repairs and adjustments such as tire rotations, cabin air filter replacement and refilling windshield fluid levels.
Maintaining fuel cell vehicles differs significantly from maintaining other cars due to handling hydrogen, an extremely flammable gas. When working on these cars, mechanics must strictly abide by all guidelines and regulations for working on them and ensure repair facilities have proper ventilation to prevent leakage of hydrogen from creating fire or explosion risks in confined spaces. Furthermore, mechanics must know how to remove and replace hydrogen tanks safely.
Once drained, hydrogen tanks must be emptied of gas using a process similar to that used with liquid petroleum gases (LPG) by opening up to three valves simultaneously and blowing out around 220 psi of hydrogen through each one of them. Once this process has completed, mechanics then flush plumbing with pure nitrogen for up to three hours afterward in order to flush away any residual hydrogen that may have been released during emptying; they then disconnect their hydrogen fuel supply line from their car before running up to three braided venting hoses out through which gas will escape into the atmosphere via braided venting hoses that lead to grounded stacks where its gas emissions into the atmosphere.
Technicians can still keep a car running while waiting for its new station by checking and replacing brakes, tires, as well as refilling and topping off windshield wiper fluid levels – this was how Mirai driver mentioned at the start of this article managed to keep hers on the road until finding another station.
However, real-world experiences of those who have used hydrogen fuel cell heavy vehicles cast doubt upon assumptions that these technologies will soon reach cost parity with battery electric or diesel-powered counterparts. A rail OEM sales executive recently noted that their prototype trains had to replace their hydrogen fuel cells after only three years of service due to wear-and-tear issues; leading them to incur significantly higher total costs of ownership compared with diesel-powered trains with similar passenger capacity.