Are hydrogen-fuelled vehicles a waste of our time and energy?
17th February 2021 | Commercial Energy
The arguments in favour of using hydrogen as an energy source – the most abundant gas in the universe, releasing only water upon combustion – appear persuasive. They weaken, however, under closer engineering examination. Hydrogen doesn’t exist to any useful extent in a free form on Earth: every molecule has to be manufactured, and the cheapest and most widespread method is by steaming natural gas. The resulting hydrogen is known as “blue” if the process includes carbon capture, “grey” if it doesn’t.
Depending on the technique used, this steam reforming requires between 33 and 50 per cent more energy than is produced by the resultant hydrogen and produces large volumes of carbon dioxide as a by-product. At utility scale, the UK government Committee on Climate Change in its 2018 report “Hydrogen in a low-carbon economy” described the need “to demonstrate that hydrogen production from [carbon capture and storage] will be sufficiently low-carbon to play a significant role” as it is presently “not close to zero-carbon” due to residual emissions of 20-30 per cent. This will not be plug and play, and perpetuates the use of fossil fuels for transport.
The alternative process of electrolysing water is expensive and needs 20-30 per cent more energy than the hydrogen energy value obtained. This method is described as “green” and promoted by wind farm owners as good use of “free” power that isn’t required by the Grid, but will always cost more than the net cost of the electrical energy used to produce and transport it. And the wind farms have to be built in the first place.
Some new wind farm developments incorporate production of hydrogen by electrolysis when their power output exceeds grid demand, and approach seen as a means to ultimately provide energy storage via the UK gas grid.
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