The hydrogen economy is one of the best kept secrets of today’s climate change movement. There are current uses for hydrogen and numerous future prospects, but it will take some technological improvements to put hydrogen as an energy source into the four corners of the economy. The question then becomes, what is the hydrogen economy, and what can it do to protect the planet from economic disaster owing to global warming.
Current Uses: Hydrogen is currently used to produce methanol, and has some industrial uses in the oil refining process. But more importantly, hydrogen is used in the production of ammonia that, in turn, constitutes the chief ingredient used in the production of artificial fertilizers needed worldwide for farming. The current process of creating hydrogen worldwide consumes a major amount of fossil fuel (primarily natural gas or coal) and emits about as much carbon dioxide as the entire German industrial economy. New technologies will be required to provide hydrogen to meet the expected demand, as the current technologies have a tendency to consume more energy than created by the hydrogen output. This is why hydrogen is used today only in fertilizers, certain explosives, and some high-performance rocket fuels along with methanol. The clean approach to hydrogen would need to come about from either electrolysis, using renewable electricity sources, or in modifying the fossil fuel approach to capture the carbon dioxide byproduct and store it underground.
Supplanting Fossil Fuels: The greater future for hydrogen may be in its potential to replace fossil fuels. Hydrogen is very energy intense—burning a kilogram of hydrogen produces about 2.6 times as much energy as burning a kilogram of natural gas. When burned, hydrogen does not produce the same damaging exhausts that fossil fuels do, such as carbon monoxide, carbon dioxide, and various sulphates. In fuel cells, where electricity is created by way of a chemical reaction involving hydrogen, only water is produced. The International Energy Agency (IEA), believes that there are immediate uses for hydrogen to replace natural gas in various capacities worldwide.
Relative Costs: The main problem with the hydrogen economy is that hydrogen as an element does not exist anywhere on the earth by itself. It’s generally combined with other elements into compounds such as water, or carbohydrates in plants. The cost per kilogram of electrolysis that separates hydrogen from water could be cut by up to ¾ if the capacity to produce electrolysis can increase in scale. Some projects for this are underway such as the Hydrogen Hub at Britain’s Humber Estuary, being built by ITM Power and Siemens Gamesa. The current benchmark for the cost of producing hydrogen is about $1 per kilogram for the fossil fuel approach known as “grey hydrogen”. “Green hydrogen,” generated via renewable electricity, could be created at the same cost in as few as two to three years if it is produced at this country’s best developed renewable locations. Transporting hydrogen could also become less expensive and more useful as countries with abundant sunshine can generate hydrogen using cheap, renewable electricity and ship it via pipeline or ocean transport.
Future Demand: The future offers the possibility of using hydrogen to decarbonize the parts of the existing economy that current efforts might not be able to reach. In this sense, the hydrogen economy may help many of the world’s countries meet their climate change goals. The Hydrogen Council, an industrial association, estimates that about 350 projects are in progress worldwide to build facilities that would enable production and distribution of clean hydrogen to replace fossil fuels in areas of industry where other methods don’t succeed. The Mitsubishi Corporation is building the facilities in Utah to produce hydrogen from renewables and store it underground. The hydrogen will then be used to power a turbine generated electrical plant that will send clean energy throughout the western electrical grid that covers five states and runs as far as Los Angeles. The demand for hydrogen can also come from industrial sources such as coking in the steel industry that need to use an inexpensive form of heat that does not create carbon emissions. Hydrogen’s major competitor in the future could be renewable electricity. Some experts don’t see many serious markets today for hydrogen versus electricity unless clear identifiable benefits occur.
Trucks, Trains, Planes: Hydrogen has the capability to power ships and aircraft via the use of fuel cells. First invented in the 1830’s, fuel cells have already been in use by NASA for several decades. Airbus is planning to use hydrogen powered planes by 2035, as the energy density of hydrogen is three times that of kerosene now commonly used by commercial jet aircraft. The caveat is that hydrogen must be liquified by chilling it to a temperature of -423 degrees Fahrenheit. Some compromise could be reached where clean hydrogen-base ammonia or synthetic hydrocarbons are used instead. Can hydrogen dominated fuel cells power the cars of the future? Perhaps, but improvements in efficiency are required, as battery powered cars are currently 50-60 % more efficient than fuel cell cars, and are cheaper to produce. Trucks might be a different story as batteries can limit the range of large transfer trucks that travel long distances. Trains may also make the shift to hydrogen power to replace diesel-powered locomotives.
Conclusion: It’s too early to declare that the hydrogen economy will save this planet from fossil fuel pollution, but there are many very good prospects for it on the horizon. What is needed is investment capital, and government support and encouragement to develop the technologies needed and to put them in place.
Sources: The Hydrogen Economy, The Economist, October 9th, 2021.
Wikipedia.