Hydrogen power

Hydrogen is an attractive fuel or power source because when used as a fuel, mixed and burned with oxygen, it produces only water and presents a carbon neutral footprint. Further, hydrogen can be used in fuel cells or in internal combustion engines and has begun to find use in passenger cars, buses, spacecraft propulsion, and electricity generation. Hydrogen, as a replacement for gasoline, offers the same energy in 2.2 pounds (1 kilogram) as gasoline offers in 6.2 pounds (2.8 kilograms). But hydrogen has a low volumetric energy when stored as a compressed gas and requires larger tanks to achieve the driving ranges of conventional gasoline powered vehicles.

Hydrogen infrastructure refers to the infrastructure of hydrogen pipeline transport, points of hydrogen production, hydrogen stations for distribution, and the sale of hydrogen fuel. These all represent prerequisites before hydrogen power can be commercialized as an alternative fuel for automotive, transport, and aeronautical fuel source. In mid-2020, there were 43 open retail hydrogen stations in the United States with a further 30 stations in various stages of planning or construction. Most of the existing or planned stations were in California, with one in Hawaii, and 12 planned stations for the northeastern states.

The need for a more extensive hydrogen infrastructure has slowed the production and adoption of hydrogen cars, which has in turn slowed the development of the necessary hydrogen infrastructure. Interest in hydrogen powered cars began in 2013, with the statements of multiple automakers and collaboration between automakers, to develop hydrogen cars. This lead to the 2015 introduction of Hyundai's NEXO and Toyota's Mirai, and the 2016 introduction of the Honda Clarity. These three models remain publicly available as hydrogen cars, and in the case of the Honda Clarity, the base model uses either lithium-ion or hydrogen fuel cells as a power source.

Similar to hydrogen cars, hydrogen planes use hydrogen as a power source. Hydrogen can either be burned in a jet engine or other kind of internal combustion engine, or can be used to power a fuel cell to generate electricity to power a propeller. Besides infrastructure challenges similar to those faced by hydrogen cars, a challenge to the use of hydrogen fuel cells in aircraft comes in the weight required for fuel storage if it is in liquid or gaseous form. For liquid hydrogen the challenge is making lightweight vacuum-insulated tanks that maintain the fuel below the 20 kelvin boiling point. Gas carries a greater weight penalty since the tanks must be built to withstand high pressures of 250 to 350 bar. Also, hydrogen powered planes require greater external surface area to accommodate for the larger hydrogen tanks and there is a need to redesign the aircraft to reduce increased aerodynamic drag.

Hydrogen is abundant in the environment, and can be produced from natural gasnatural gas, nuclear power, biomass, water, and renewable power such as solar and wind. There are four general processes for producing or separating hydrogen: thermal process, electrolytic process, solar-driven process, and biological process.

Hydrogen infrastructure refers to the infrastructure of hydrogen pipeline transport, points of hydrogen production, hydrogen stations for distribution, and the sale of hydrogen fuelhydrogen fuel. These all represent prerequisites before hydrogen power can be commercialized as an alternative fuel for automotive, transport, and aeronautical fuel source. In mid-2020, there were 43 open retail hydrogen stations in the United States with a further 30 stations in various stages of planning or construction. Most of the existing or planned stations were in California, with one in Hawaii, and 12 planned stations for the northeastern states.

In the United StatesUnited States, most of the hydrogen produced each year is used for refining petroleum, treating metals, producing fertilizer, and processing foods. However, NASA has used hydrogen since the 1970s to propel space shuttles and other rockets into orbit. As well, hydrogen fuel cells are used to power the shuttle's electrical systems and the water, which is produced as a byproduct of a hydrogen fuel cell, is consumed by the crew as drinking water.

Meanwhile, in 2020, Mercedes-Benz, which began research and developing hydrogen fuel-cell powered passenger cars 30 years prior, announced they were ending their hydrogen fuel cell powered passenger car program. In 2013, Mercedes-Benz entered a collaboration with Ford and NissanNissan to develop hydrogen powered vehicles. Mercedes-Benz produced one production-possible model, the GLC F-Cell, which was used for business promotions and demonstrating the possibility of developing hydrogen cars. However, the GLC F-Cell was never offered for sale to the public due to high manufacturing costs. The same manufacturing costs were part of the reason for ending the development program.

Hydrogen cars work on the same principles of electric cars, such that they are essentially electric vehicles (in most cases) except that instead of lithium-ion batteries as a fuel source, hydrogen cars use hydrogen fuel cells. And the use of a hydrogen fuel cell in place of a lithium-ion battery offers certain advantages, including the ability to be refueled in about 5 minutes compared to the possible hours that can be necessary to charge a battery. Hydrogen cars also have travel ranges similar to gasoline vehicles, with the smallest range belonging to the Toyota Mirai at 317 miles on a full tank, which can in turn be compared to the 220 mile range of the base model TeslaTesla Model 3.

In the European UnionEuropean Union, the adoption of hydrogen fuel cell heavy transport trucks may happen in response to the 2025 emissions limits being placed on the heavy transport industry which requires a 15 percent limit in emissions. These emissions limits are increased again in 2030 to a 30 percent limit in emissions. Also, emerging methods of chemically bonding hydrogen or using ammonia to transport hydrogen present a stable transportation and storage method that does not require the pressurization or cryogenic liquefaction current hydrogen power requires. These methods would also require less energy for transportation and storage.

Hydrogen infrastructure refers to the infrastructure of hydrogen pipeline transport, points of hydrogen production, hydrogen stations for distribution, and the sale of hydrogen fuel. These all represent prerequisites before hydrogen power can be commercialized as an alternative fuel for automotive, transport, and aeronautical fuel source. In mid-2020, there were 43 open retail hydrogen stations in the United States with a further 30 stations in various stages of planning or construction. Most of the existing or planned stations were in California, with one in HawaiiHawaii, and 12 planned stations for the northeastern states.

In 2008, BoeingBoeing built and operated the first aircraft to fly solely on hydrogen power. The fuel cells on the single person plane were supplemented with power from lithium-ion batteries during takeoff and ascent. Four years following this flight, Boeing released the Phantom Eye, a liquid-hydrogen-powered unmanned aerial vehicle designed to fly reconnaissance missions of up to four days at an altitude of 20,000 meters. The company was unsuccessful selling the UAV to the military. Whereas Airbus has publicly stated they will decide by 2025 whether to manufacture hydrogen-powered aircraft. Their decision depends on whether the market can support these airliners.

In the United States, most of the hydrogen produced each year is used for refining petroleum, treating metals, producing fertilizer, and processing foods. However, NASANASA has used hydrogen since the 1970s to propel space shuttles and other rockets into orbit. As well, hydrogen fuel cells are used to power the shuttle's electrical systems and the water, which is produced as a byproduct of a hydrogen fuel cell, is consumed by the crew as drinking water.

When stored, hydrogen can be stored physically as either a gas or a liquid. The storage of hydrogen gas typically requires high-pressure tanks (around 250 to 700 bar). Storage of hydrogen as a liquid requires cryogenic temperatures due to the boiling point of hydrogen at one atmosphere pressure being -252.8 degrees Celsius. Hydrogen can also be stored on the surface of solids or within solids, by absorption. The more popular version of hydrogen storage for portable and stationary storage is to store it compressed in gaseous form. The footprint of compressed gas tanks are easier to accommodate than a cryogenic liquid hydrogen storage unit. However, for fuel cell vehiclesfuel cell vehicles, which require at least enough hydrogen to provide a driving range of 300 miles or more, the required storage volumes for compressed gas may be higher than can be reasonably accommodated.

Hydrogen use as a power source for heavy transport trucks is similar to the ideas for electric powered heavy transport truck, and faces similar challenges to hydrogen powered cars. The high energy density of hydrogen and the available space in truck cabs also make hydrogen a possible option for heavy-goods transport vehicles. As well, hydrogen power for the industry is seen as a more attractive option compared to lithium-ion electric powerelectric power because hydrogen has less downtime for fueling compared to the hours of downtime lost to recharging batteries. This downtime can represent lost income for heavy transport trucks. Although hydrogen-powered heavy transport trucks suggest a possible range of 500 miles, better compared to the 300 miles electric powered heavy transport trucks have been quoted at, but nowhere near the 1000 miles traditional diesel engines can achieve.

The need for a more extensive hydrogen infrastructure has slowed the production and adoption of hydrogen cars, which has in turn slowed the development of the necessary hydrogen infrastructure. Interest in hydrogen powered cars began in 2013, with the statements of multiple automakers and collaboration between automakers, to develop hydrogen cars. This lead to the 2015 introduction of Hyundai's NEXO and Toyota's Mirai, and the 2016 introduction of the Honda ClarityHonda Clarity. These three models remain publicly available as hydrogen cars, and in the case of the Honda Clarity, the base model uses either lithium-ion or hydrogen fuel cells as a power source.

Hydrogen cars work on the same principles of electric cars, such that they are essentially electric vehicles (in most cases) except that instead of lithium-ion batteries as a fuel source, hydrogen cars use hydrogen fuel cells. And the use of a hydrogen fuel cell in place of a lithium-ion battery offers certain advantages, including the ability to be refueled in about 5 minutes compared to the possible hours that can be necessary to charge a battery. Hydrogen cars also have travel ranges similar to gasoline vehicles, with the smallest range belonging to the Toyota MiraiToyota Mirai at 317 miles on a full tank, which can in turn be compared to the 220 mile range of the base model Tesla Model 3.

The need for a more extensive hydrogen infrastructure has slowed the production and adoption of hydrogen cars, which has in turn slowed the development of the necessary hydrogen infrastructure. Interest in hydrogen powered cars began in 2013, with the statements of multiple automakers and collaboration between automakers, to develop hydrogen cars. This lead to the 2015 introduction of HyundaiHyundai's NEXO and Toyota's Mirai, and the 2016 introduction of the Honda Clarity. These three models remain publicly available as hydrogen cars, and in the case of the Honda Clarity, the base model uses either lithium-ion or hydrogen fuel cells as a power source.