As governments around the world scramble to find ways to reform energy systems to meet climate commitments, hydrogen looms large. Fuel is now considered a mainstay of most net zero emissions scenarios. Production should at least quintuple by the middle of the century.
On one level, the enthusiasm is understandable. If hydrogen were freely available, it would be a decarbonization wonder. It can make carbon-free fuels for transportation and heating, and power some energy-intensive industries that can’t be easily electrified, such as steel or fertilizer manufacturing (see Characteristic).
The problem is that hydrogen is not freely available. On Earth, it exists primarily in molecules bound to other elements, from which it must be extracted at enormous energy cost. Policy makers should be wary of the potential unintended negative consequences for people and the planet of an overworked hydrogen rush.
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Most hydrogen is currently made by processes – such as the steam reforming of natural gas (methane) – that produce large amounts of CO2 as a by-product. Although “green” hydrogen can be made using electricity from renewable sources to separate water molecules, this process is expensive compared to more conventional production methods.
It can also be an inefficient use of renewable resources. Using green electricity to produce hydrogen at peak times, when this energy could feed into the grid and displace electricity generated from fossil fuels, could lead to higher than expected overall emissions. Making hydrogen with electricity generated from the relentless use of fossil fuels would be even worse.
All of this means that hydrogen must be used wisely, to deal with emissions that cannot be eliminated by other means. Many vaunted uses do not check this box. For example, some groups advocate burning hydrogen to heat homes, as an alternative to natural gas, but this is much less efficient than using electricity directly. In the immediate term, this means higher costs for consumers. But it also means that even using really green hydrogen to heat homes displaces a smaller portion of the current CO2 less emissions than using it for other tasks, for which there is no alternative.
Another example is hydrogen cars and vans. The European Union has just joined many countries in reaching an agreement to ban the sale of cars and vans equipped with internal combustion engines. By 2035 all new cars on the block will be zero emissions, part of the ‘Fit for 55’ campaign to cut carbon emissions by 55% by 2030. But industry groups and some governments would like continue to authorize vehicles that run on hydrogen-based “e-fuels”. These fuels could one day be an effective tool to decarbonize certain trucks, large ships, planes and other means of transport for which battery technologies are not currently suitable. But they are a distraction when it comes to personal vehicles, for which efficient batteries are already available.
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The EU is also under pressure from industry to water down the definition of green hydrogen and to subsidize ways to make gas that still carries unacceptable emission rates, as part of Fit for 55. the past occasions when the bloc adopted policies that looked eco-friendly on paper, but came with a lot of fine print. Counting wood-based energy as renewable, for example, has caused the destruction of forests in Europe and elsewhere, with no positive impact on carbon emissions.
The United States set a better example with the passage in August of the Cut Inflation Act, which subsidizes the production of genuine green hydrogen by up to $3 per kilogram, and provides lower subsidies for more expensive versions. dirty. Globally, however, hydrogen production and trade would benefit from clear and uniform rules on how hydrogen should be made and under what circumstances its use is beneficial. The Hydrogen Council, a Brussels-based industry group, is pushing for international standards and certification schemes for green hydrogen production.
These standards should be accelerated. But, when defining net zero strategies, policymakers should not lose sight of the ultimate goal: to stay within a total carbon budget compatible with the Paris climate agreement. As attractive as that may sound – and however real the opportunities may be, for example in the decarbonisation of heavy industry – often the answer is not hydrogen.