Reverse electrolysis is a straightforward, yet powerful tool: Combining hydrogen and oxygen in a fuel-cell generates electricity that can power almost anything from cars, trains, airplanes to – in the long run – entire economies.
Using hydrogen as a fuel is not a new idea. As early as 1874, technophile author Jules Verne had Cyrus Smith, one of the characters in the novel The Mysterious Island, describe the potential of this most abundant element in the universe.
The vision of hydrogen-powered mobility is indeed compelling: Mass market cars with a built-in power plant that drives the automobile over a range comparable to that of conventional combustion engines while the exhaust pipes emit nothing but droplets of clean water.
So-called Fuel Cell Electric Vehicles (FCEV) produce significantly less emissions than traditional cars. While there are always zero direct exhaust fumes from the car, the overall emissions (“well-to-wheel”) depend on the energy type used for the hydrogen production. If renewable energy is used – and this is the target! – they can be zero. Even if natural gas is utilised, the overall emissions are 20-30% lower than for traditional cars. At the same time, a fuel cell coupled with an electric motor is two to three times more efficient than a combustion engine running on gasoline.
Some 400 million cars, 15-20 million trucks and around 5 million buses could be powered by hydrogen in 2050, according to projections by the Hydrogen Council, an industry group including Linde that promotes greater use of hydrogen. This would contribute more than one-third of the total CO2 reduction required for the road transportation sector in the 2˚C scenario.
Some 400 million hydrogen-powered cars like this model from Hyundai (Image: Hyundai) could be roaming the streets in 2050.
Widespread use of hydrogen is a deciding factor in slowing global warming.
Mobility is just one example. Hydrogen’s key advantage is its ability to interlink sectors, that is ferry green energy from one sector to another. Take “Energiepark Mainz”, for example, where partners such as the Mainzer Stadtwerke, Siemens and Linde cooperate to convert wind power into hydrogen, for example to heat buildings and supply gas power plants, which in turn generate electricity.
In total, hydrogen could account for almost 20% of total final energy consumed by 2050. The market for the gas itself and related technologies would amount to two trillion Euro per year, says the Hydrogen Council. And jobs for more than 30 million people globally.
Commanding the weather gods
Hydrogen is ideally placed to address some of the most pressing challenges of our times: environmental pollution and global warming. The decarbonization necessary to limit global warming to a 2˚C scenario is hardly conceivable without hydrogen supporting the use of renewable energies.
Solar and wind power are crucial for a low-carbon economy. Yet the weather gods can hardly be controlled and output from wind- and solar parks is highly volatile. Hydrogen can empower renewable energy sources. Better equipped than conventional batteries to store surplus energy over long periods of time, hydrogen can absorb energy during peak production times, store it and have it ready for later use or long-distance shipment.
Yet the trouble with hydrogen is electrolysis. Despite their abundance, hydrogen atoms are rarely found on their own. With a propensity to combine with other elements, they tend to form compounds like water and methane. In other words: To produce pure hydrogen, water, for example, has to be forcefully split into its two components, hydrogen and oxygen. This – like other methods to generate hydrogen such as steam reforming, renewable liquid reforming and fermentation – requires energy input.
Hydrogen atoms are almost omni-present, yet energy input is necessary to generate pure hydrogen.
Other challenges remain as well. Many countries lack the infrastructure to make this alternative energy carrier widely attractive. The Hydrogen Council estimates annual investments of 16-20 billion Euro until 2030 to build up a hydrogen-based economy. Roughly half of that would be needed to develop the necessary infrastructure such as transport and storage facilities as well as scaling up production equipment.
Hydrogen-powered vehicles are hardly a bargain either. Models by the leading manufacturers in the field today cost between 60,000 Euro and 80,000 Euro. Industry players are also well advised to reduce the cost of hydrogen if they want to make it competitive with rival fuels.
Infrastructure such as fuelling stations needs to be expanded if hydrogen is to become a viable alternative fuel.
When if not now?
Yet the conditions to kick-start the hydrogen economy have never been better. A growing awareness for global warming and the debate over harmful emissions from conventional combustion engines cause hydrogen initiatives to spring up in countries around the globe.
The UK is investigating a city-by-city transition to replace natural gas with hydrogen in heating and powering buildings. Linde strongly supports the build-up of hydrogen-based corporate fleets as well as the construction of 400 hydrogen fueling stations in Germany by 2023.
At the end of 2017, Japan formulated a strategy for promoting the adoption of hydrogen as an energy resource. One goal is for hydrogen in 2050 to cost one-fifth as much as now, a cost reduction which would make it competitive with gasoline and liquefied natural gas. The plan envisions 40,000 fuel cell vehicles in operation by 2020 and 800,000 by 2030. It also calls for 320 hydrogen fueling stations by 2025.
Wuhan, the capital of China’s Hubei Province, is said to develop a “hydrogen city” to advance research and development in the field. In the US, California, where most of the nation’s 50 hydrogen fueling stations are located, is leading the charge.
Almost 150 years ago, Cyrus Smith, the engineer in Jules Verne’s novel, predicted that hydrogen would become the coal of the future. It is now time to turn this vision into reality.