Background

1806: The First Hydrogen-Powered Engine

The first internal combustion engine was powered not by gasoline but by a mix of hydrogen and oxygen in 1806. Swiss engineer Francois Isaac de Rivaz contained hydrogen gas in a balloon and used an electrical Volta starter for the ignition.

The 1930s: A New Hydrogen Vehicle Emerges

Fast-forward to 1933 and the birth of the next hydrogen vehicle. Norway's Norsk Hydro power company developed a hydrogen-powered truck that used an internal combustion engine propelled by extracted hydrogen from an ammonia reformer.

The 2000s: Modern Fuel Cells Revolutionize Hydrogen Technology

As the new millennium began, concerns over emissions, efficiency and energy security began to surface. Increased focus on reducing dependence on fossil fuels was a catalyst for revisiting the development of fuel cells as a sustainable energy source.

Introduction to Hydrogen Engine Vehicles

Definition and explanation of Hydrogen Engine Vehicles

Hydrogen engines are just modified internal combustion engines. The hydrogen fueling infrastructure developed for the applications of one can serve the applications of the other. And, any development towards more economical onboard hydrogen storage is entirely applicable to both.

In the electricity sector, power-to-hydrogen and hydrogen-to power-technologies such as hydrogen combustion turbines are rapidly developing. In the transportation sector, initial attention was focused on fuel cell hydrogen electric vehicles, or FCEVs. More recently, hydrogen vehicles powered by internal combustion engines are also receiving increased attention, especially among medium and heavy-duty trucking applications.

Hydrogen engines can enable your journey to destination zero using carbon-free hydrogen fuel as FCEVs, and use technology familiar to vehicle manufacturers, fleets and drivers.

Vehicles with hydrogen internal combustion engines can operate without any CO2 emissions coming from the hydrogen fuel, direct or indirect, depending on the source of the hydrogen used.

Hydrogen produced by electrolysis using electricity coming from solar panels or wind turbines, for example, enables CO2-free driving. Additionally, hydrogen fuels do not release any particulate matter, carbon monoxide, or volatile organic compounds.

Types Of Hydrogen Engine Vehicles

FCEVs

Fuel Cell Electric Vehicles (FCEVs) utilize a hydrogen fuel cell to produce electricity that powers an electric motor. The hydrogen stored in high-pressure tanks combines with oxygen from the air to create a chemical reaction that generates electricity and water as a byproduct. FCEVs have zero tailpipe emissions, and their energy efficiency is higher than conventional internal combustion engine vehicles.

HICEVs

Hydrogen Internal Combustion Engine Vehicles (HICEVs) use hydrogen as a fuel source in a modified internal combustion engine. Instead of gasoline, hydrogen is injected into the engine, where it combusts with oxygen to produce power. The primary emissions from HICEVs are water vapor and minimal nitrogen oxides, making them a cleaner alternative to gasoline vehicles.

PHHVs

Plug-in Hybrid Hydrogen Vehicles (PHHVs) combine the technologies of FCEVs and plug-in electric vehicles. PHHVs have both a hydrogen fuel cell system and a battery that can be recharged from an external power source. This dual system allows the vehicle to run on either hydrogen or electricity, offering flexibility and reducing the reliance on hydrogen refueling infrastructure.

Key Components of a Hydrogen Fuel Cell Electric Car

Like all-electric vehicles, fuel cell electric vehicles (FCEVs) use electricity to power an electric motor. In contrast to other electric vehicles, FCEVs produce electricity using a fuel cell powered by hydrogen, rather than drawing electricity from only a battery. During the vehicle design process, the vehicle manufacturer defines the power of the vehicle by the size of the electric motor(s) that receives electric power from the appropriately sized fuel cell and battery combination. Although automakers could design an FCEV with plug-in capabilities to charge the battery, most FCEVs today use the battery for recapturing braking energy, providing extra power during short acceleration events, and to smooth out the power delivered from the fuel cell with the option to idle or turn off the fuel cell during low power needs. The amount of energy stored onboard is determined by the size of the hydrogen fuel tank. This is different from an all-electric vehicle, where the amount of power and energy available are both closely related to the battery's size.

Battery (auxiliary): In an electric drive vehicle, the low-voltage auxiliary battery provides electricity to start the car before the traction battery is engaged; it also powers vehicle accessories.

Battery pack: This high-voltage battery stores energy generated from regenerative braking and provides supplemental power to the electric traction motor.

DC/DC converter: This device converts higher-voltage DC power from the traction battery pack to the lower-voltage DC power needed to run vehicle accessories and recharge the auxiliary battery.

Electric traction motor (FCEV): Using power from the fuel cell and the traction battery pack, this motor drives the vehicle's wheels. Some vehicles use motor generators that perform both the drive and regeneration functions.

Fuel cell stack: An assembly of individual membrane electrodes that use hydrogen and oxygen to produce electricity.

Fuel filler: A nozzle from a fuel dispenser attaches to the receptacle on the vehicle to fill the tank.

Fuel tank (hydrogen): Stores hydrogen gas onboard the vehicle until it's needed by the fuel cell.

Power electronics controller (FCEV): This unit manages the flow of electrical energy delivered by the fuel cell and the traction battery, controlling the speed of the electric traction motor and the torque it produces.

Thermal system (cooling) - (FCEV): This system maintains a proper operating temperature range of the fuel cell, electric motor, power electronics, and other components.

Transmission (electric): The transmission transfers mechanical power from the electric traction motor to drive the wheels.

Working principle of FCEV

How Does a Fuel Cell Work?

A fuel cell generates electricity through an electrochemical reaction of hydrogen and oxygen that occurs within the vehicle itself. In contrast, the electricity for a BEV is generated outside the vehicle and stored in the vehicle's battery pack. So, a big advantage of FCEVs versus BEVs is fuel cells don't require recharging like batteries. Instead, they continue to produce electricity as long as hydrogen and oxygen are available to the car's fuel cell.

A fuel cell has an anode, cathode, and an electrolyte membrane. It creates an electric current by passing hydrogen through the anode and oxygen through the cathode. At the anode, a catalyst splits the hydrogen molecules into electrons and protons. The protons pass through the porous electrolyte membrane, while the electrons are forced to a circuit as an electric current. At the cathode, the protons, electrons, and oxygen combine to produce water molecules.

Byproducts of this process are water, typically in vapor form, and heat. With no moving parts, fuel cells operate silently and reliably. The fuel cell's waste heat can be used for heating or cooling.

How Does a Fuel Cell Vehicle Work?

Like battery-electric vehicles, fuel cell vehicles use electricity to power one or more electric motors that drive the wheels. In an FCEV, the electricity comes directly from the fuel cell or from an onboard battery pack that stores both excess electricity and electricity generated by regenerative braking. That process, also used in BEVs and hybrids, saves energy that would otherwise be lost as heat during braking. The amount of energy available to drive an FCEV is the sum of the electricity produced by the hydrogen stored in a tank onboard and the energy stored in the battery pack.

During driving, a simple transmission delivers electricity from the fuel cell and/or from the battery pack to the electric drive motor(s) powering the vehicle. An electronics controller manages the flow of electricity, thus controlling the speed and torque of the electric drive motor. Additionally, an FCEV also has a cooling system that maintains the proper operating temperature range of the fuel cell, electric motor, power electronics, and other components.

The hydrogen fuel is stored in a pressurized tank designed specifically for that use, and the fuel filler is significantly more high-tech than the nozzle on a gasoline pump at the local gas station. Though more complicated, hydrogen refueling is only slightly more difficult than putting gas in a conventional car, and the process takes a comparable amount of time.

Why Aren't There More Fuel Cell Vehicles?

Fuel cell vehicles offer several advantages over battery electric vehicles, most notably when comparing refueling versus recharging times. Furthermore, in an FCEV, electricity is generated onboard producing only heat and water vapor while a BEV operates on electricity produced elsewhere, typically by fossil-fuel-powered generating plants. However, the process of manufacturing the hydrogen fuel used to power an FCEV is not always clean, either.

Working Principle of Hydrogen Engine Vehicles

Using hydrogen to power an engine or motor is more straight forward than you might think. There are two ways to do this.

• The first way involves a device known as a fuel cell. The fuel cell converts hydrogen to electricity, which then powers the vehicle's electric motors, just like in any electric vehicle.
• In fact, one of the very first internal combustion engines ran on a mixture of hydrogen and oxygen—and featured an electric spark ignition mechanism. Its inventor, a former Swiss artillery officer named François Isaac de Rivaz, used it to build a vehicle that could carry heavy loads over short distances.
• The other way is hydrogen engines; internal combustion engines that burn hydrogen as the fuel. Either method has its advantages and applications where they are best suited. However, the latter, using internal combustion engines is a more familiar technology.
• Today, if you saw a modern internal combustion engine designed to run on hydrogen, you might not know that it's not meant for natural gas. Four-stroke hydrogen internal combustion engines (Hydrogen ICE) operate on the same cycle as regular natural gas engines and have almost the same components—engine block, crank, cylinder heads, ignition system, installation parts, and so on.

Benefits of Hydrogen Engine Vehicles

Hydrogen vehicles - whether powered by a fuel cell or an internal combustion engine—do run with a zero-carbon emission fuel: hydrogen. But measuring CO2 generated at the well-to-wheel level is a little more complicated. It depends on the source of the hydrogen and how it's made. Traditionally, hydrogen production comes from an industrially process known as steam methane reforming. Steam methane reforming causes significant quantities of CO2 to be released. Hydrogen produced in that manner is known as gray hydrogen and is used in large quantities in chemical and petrochemical industries.

Safety: Because it is 14 times lighter than air, a narrow, vertical flame is produced in the event of a point leak in the tank, which does not create a high temperature and does not spread. There was even an experiment, where a tank in a hydrogen car was deliberately damaged. The gas burned out in no time, and no trace of the fire remained except for a windshield temperature rising to 47°C. In spite of this, manufacturers are doing their best to ensure that the hydrogen fuel storage tanks they produce meet all safety requirements.

Operating Cost: The cost of operating a hydrogen car could ultimately be lower than comparable alternative technologies, although the final price of hydrogen as a fuel will depend on a number of factors, such as the cost of manufacturing and the energy required to do so, or the rates of locally imposed taxes.

Environmental Impact: The most important advantage of using hydrogen cells is that they do not emit harmful substances into the atmosphere. This type of vehicle produces only water while driving, making it completely harmless to the environment. Since hydrogen as a fuel has a high fuel value, the ranges of hydrogen-fueled vehicles are comparable to combustion cars, and they recharge quickly, just as with LPG. In addition, hydrogen as an element is ubiquitous in nature, so its supply will not be depleted.

Performance: Hydrogen fuel cell cars are quiet, very energy efficient, produce no emissions and have equivalent range and performance to gasoline counterparts. Drivers identify range, refueling time, emissions, power and performance as valuable vehicle characteristics.