Hydrogen – vehicle propulsion of the future?

In June 2019, the UK Government revised the UK’s legislated target for the reduction of greenhouse gas emissions from at least 80% to 100% by 2050.¹

To achieve a net zero environment, changes in all elements of life will be required, from the design of domestic central heating boilers to propulsion in all forms of transport.

The UK governments proposal to ban the sale of all petrol and diesel-engined cars by 2032² has meant car manufacturers need to be fully invested in a zero-emissions future. As such, we are seeing significant acceleration in the production of electric vehicles utilising batteries as a primary energy storage.

Although battery design has evolved and continues to evolve, electric vehicle (EV) designers are presented with technical and cultural challenges including:

• Batteries, although improving are bulky and heavy;
• Batteries present significant issues in the design of commercial vehicles restricting payload volumes and axle weights;
• The operating range of electric vehicles is a key and limiting constraint in long-distance travel where exact routing and journey times can be unpredictable. The issue of drivers having range anxiety is well documented.
• Batteries take a significant amount of time to recharge and if this is accelerated, a reduction in battery life can occur resulting in significant additional cost;
• The decommission and disposal of spent batteries in an environmentally appropriate way is presenting challenges;
• Changes in the availability of base materials including lithium and the environmental considerations in its extraction.

There has recently been a significant upsurge in the use of alternative fuels and the spotlight has swung in the direction of hydrogen and the development of fuel cell technology.

Is hydrogen an alternative? Let’s understand more.

Hydrogen is all around us in water and can be separated by a chemical process called electrolysis. In the simplest of explanations, an electrical current is passed through water causing hydrogen gas to be generated which is then extracted and collected. The process is more efficient if the water is made to better conduct electricity, hence the reason why either seawater or brine is used in the process.

Hydrogen gas then needs to be compressed and delivered to a point of purchase in a similar way to the current transportation of fossil-based products.

The vehicles themselves are fitted with a fuel cell and are known as Fuel Cell Electric Vehicles (FCEV).

Again, in the simplest of terms the process can be considered in the reverse of how hydrogen is produced – hydrogen gas and the oxygen in air are introduced into a fuel cell normally consisting of compressed layers of spacers and conductive membranes. The reaction of hydrogen to oxygen causes an electrical charge to be generated with the biproduct being water. The flow rate of the gases is controlled thus controlling the amount of electrical energy generated. This electrical energy is used directly to power electric motors to propel the vehicle.

On the face of it, this technology meets all the requirements for green technology particularly when it is considered that the only emissions from a fuel cell is water vapour and there are some advantages in comparison to battery powered systems:

• Hydrogen storage tanks on a vehicle although significant in size and pressurised to very high pressures, contain a lighter than air gas which means vehicle weights are reduced;
• Weight savings enable more scope for incorporation in commercial vehicle applications;
• Compressed hydrogen can store more energy enabling a vehicle to have a higher range;
• Depending on the vehicle type and capacity, hydrogen-fuelled vehicles can be recharged in around seven minutes;
• The construction of the fuel cell and the associated ancillaries does not present an environmental concern in terms of disposal or decommissioning

The weight reduction is a key consideration as it means that the door could be open to utilisation of this technology in more weight critical forms of transport such as aircraft, shipping and rail.

This sounds great and makes hydrogen a key contender – or does it ?

• The process to produce hydrogen  into a compressed gas requires electricity;
• There is a cost to transport and store the gas at the user distribution outlet.
• Does the bulk transport and storage of hydrogen present any greater road or property risk?

Therefore, if hydrogen could be produced utilising green energy such as wind farms and solar power and ideally produced locally to the point of sale, some of the above challenges are overcome.

Will hydrogen propulsion be the betamax of propulsion ?

Currently we believe the development of hydrogen systems is around four – five years behind battery systems and so focus presently is on the here and now - areas which include battery technology.

Therefore, to progress this technology, significant direction and financial investment will be required from government to support the introduction of this technology. One way may be to develop the technology in a specific area, eventually widening the catchment area as take-up in the usage increases.

Until usage becomes more widespread, a chicken and egg situation is in place with potential users not obtaining vehicles because there is nowhere to refuel. An electric vehicle can be refuelled at home.

Investment is occurring, with the UK government is currently committing a £28 million investment in five projects³

Dolphyn - Offshore generation of hydrogen utilising wind power and seawater

Hynet – Production of a clean hydrogen production facility

Gigastack – Development of PEM (Polymer Electrolyte Membranes)

Acorn Hydrogen Project – Hydrogen production from North Sea Gas

Cranfield University – Hydrogen generation through steam reforming

There are other areas of investment occurring through other programmes.

The Joint Initiative for hydrogen vehicles known as JIVE and JIVE2, funded by the EU are introducing new fleets of hydrogen powered buses including the set-up of hydrogen cities to further develop transport in given areas. Areas defined in the UK include Aberdeen, Birmingham, Brighton, Dundee and London, and this is set to be discussed further at the COP 26 Climate Summit in Glasgow later in 2020.⁴

Fuel cell vehicles currently exist is the product ranges of Honda and Toyota and BMW have recently announced that an FCEV product would be available in 2022.

Many bus manufacturers either have or are developing FCEV products as passenger transport is seen as a key user. Particular attractions include:

• The speed of refuelling, enabling better utilisation of assets and the operating range advantages;
• Minimalisation of the significant capital costs of vehicle battery ownership;
• The constraints sometimes seen in electrical power distribution to power recharging stations.

Is hydrogen technology safe?

All systems powering vehicles incorporate some method of providing stored energy.

Each presents differing risks and in the case of hydrogen, gas leakage providing fuel for a source of ignition is seen as the most significant risk with thermal runaway of batteries presenting significant risk with battery vehicles.

The identification, control and management of these risks continues to be key.

At Willis Towers Watson our client base enables us to have unique insight across many industries including manufacturers and operators of all modes of transport.

We continue to support and assist our clients in managing risks as new technology emerges and becomes a reality of day to day fleet operations.

For further information or guidance please contact Andrew Millinship.

Footnotes

¹ https://www.gov.uk/government/news/uk-becomes-first-major-economy-to-pass-net-zero-emissions-law

² https://www.autocar.co.uk/car-news/new-cars/petrol-and-diesel-car-sales-ban-could-come-2032

³ Source Department for Business, Energy and Industrial strategy https://www.gov.uk/government/publications/hydrogen-supply-competition/hydrogen-supply-programme-successful-projects-phase-2

⁴ https://www.fuelcellbuses.eu/sites/default/files/documents/Knowledge%20Brief-%20Fuel%20Cell%20Buses_web.pdf

Author

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Andrew Millinship

Practice Leader – Transport Risk

email Email phone +44 0 7764 836 394

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