However, some believe the simplest solution is just to electrify everything.
But, in itself, that is a misconception. The world already produces 115 million tonnes of hydrogen each year for use in industrial processes. This is not a role that can be filled by electricity.
In other sectors, it’s going to be horses for courses. Hydrogen won’t be the best solution for everything, but neither will electricity.
In fact, renewable generation and hydrogen production sit very comfortably alongside each other. By storing electrons from large-scale renewable energy projects as hydrogen or hydrogen carriers (ammonia, methanol, etc.), we can widen the reach of renewable power and repurpose it for use in other sectors, while still ensuring that excess capacity is available for use as electricity if the need arises.
We posed this question and others to UNSW Scientia Professor Rose Amal, a hydrogen expert and the Co-Director of GlobH2E—the ARC Industrial Transformation Training Centre for the Global Hydrogen Economy— and lead of NSW Power-to-X.
"As long as it has been generated through renewable resources, electrification is a good solution to net-zero emissions in its own right.
The obvious advantage of being able to use renewable energy directly is that we don’t experience energy losses like we would do if we turned it into hydrogen—which is particularly important if the plan is then to turn it back into electricity after it has been stored for a while as hydrogen.
But that doesn’t mean electrification is the solution to everything, everywhere.
One of the problems is that electricity is not always a suitable replacement for what’s currently in use.
The world already produces around 115 million tonnes of hydrogen each year, almost exclusively through the use of fossil fuels. Two-thirds of this is used in manufacturing ammonia and refining petrol. This is not a role that can be filled by electrification—hydrogen can provide industrial heating at temperatures electricity cannot.
Our own economy is driven by some heavy emitting industries, like fertiliser and chemical manufacturing, mining, oil and gas, maritime and transportation. Between them, transport, agriculture and industrial processes account for nearly 40% of our emissions.
These are hard-to-abate sectors and cannot easily be electrified. Hydrogen and its derivatives, whether green or clean, are really the only way forward if we are going to substitute renewable fuels into these industries and remove fossil fuels."
“In other areas, like the automotive industry, studies have shown that battery-powered electric vehicles are more likely to suit day-to-day car journeys. But for long-haul trucks and heavy mining vehicles, for example, hydrogen-powered fuel cells appear more suitable.
The current thinking is that some select transport applications, including railways, aviation and shipping might well run on hydrogen and hydrogen carriers (like ammonia).
In residential settings, more than 5 million households in Australia rely on gas for heating. Whether they will transition to electricity or use a blend of hydrogen is, as yet, unknown. And we’re already seeing movement on this. In New South Wales, a trial by the Jemena Gas Network is already underway to blend hydrogen into the natural gas system delivered to homes.
Several other gas networks around Australia are also considering the impacts of using hydrogen as they upgrade their assets to ensure they will remain compatible in the event of a transition.
Further afield, Scotland has a trial underway that uses pure hydrogen to power boilers and stovetops for 300 people.
Generators are also looking at hydrogen; the Tallawarra B power station in NSW will be using a 5% hydrogen blend to generate power.
Finally, it’s worth noting that renewable generation sits very comfortably alongside the production of hydrogen and other fuels. At present, when we have an excess supply of renewable energy, we look to store it in vast banks of batteries or pumped hydro."
"But my view is this is a missed opportunity; it’s a little like pouring your entire life savings into an everyday transaction account so that you always have access to them. A wiser investor would make at least a proportion of their money work much harder.
If we extend the analogy a little further, when you pay money into a bank, it doesn’t just sit there, gathering dust. The bank uses it to make its own money by investing it elsewhere or lending it to others. At the same time, the money is still available to you to withdraw whenever you need it.
By converting renewable energy to chemical energy—a process we call Power-to-X—we can do something similar. By storing electrons from large-scale renewable energy projects as hydrogen or ammonia, we can widen the reach of renewable power and repurpose it for use in other sectors while still ensuring that excess capacity is available for use as electricity if need be."