Op-Ed: The future of ADF mobility and energy security beyond naturally occurring fossil fuels

There are already advocates for zero carbon emissions by 2050, for example the Australian Labor Party although they were probably not thinking specifically about mobility in crafting that policy. Even further from their thoughts was the essential mobility of the Australian Defence Force.

Current reliance on fossil fuels

Yet the deep concerns on the lack of oil fuel reserves and uncertain refinery operations in Australia such as expressed recently by Air Vice-Marshal (Ret’d) John Blackburn, AO, are matters of immediate priority. He has advocated government intervention to maintain the viability of Australian oil refineries, and then the exploration of a number of aspects of our national supply chains for oil fuels.

All well and good, but we must also think outside the square as is happening right now in the maritime and automotive industries to look for alternatives to fossil fuels – not only for the vulnerability to global supplies and price fluctuatiions such as we have in Australia, but as a major contribution to the 2050 zero emissions target that is being increasingly recognised as a necessary step to address global warming

Shift to electric vehicles

There is wide publicity on the transition to electric vehicles and for shorter range operations where there is a reliable and readily available source of recharging services this will suffice. There are some questions about the supply of the materials for the batteries but there are also encouraging signs that research and development of battery technology is advancing steadily.

But this does not address the full mobility needs for the ADF which include long-range, long endurance air, surface and undersea vehicles which must be supported fully even when fossil fuels are unavailable or eventually no longer in use in the wider community.

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Maritime shift to LNG

For maritime vessels, ships, submarines and undersea vehicles that may be unmanned and remotely operated or autonomous, the United Nations International Maritime Organisation (IMO) target is to halve emissions by 2050, but this will be challenged as not good enough and zero emissions should be the target as it is for other domains.

The current step in shipping is to shift from the present low sulphur fuels to liquefied natural gas (LNG) as the next step, as LNG has lower carbon emissions for the same energy output compared with diesel oil fuel.

However, that will not meet the zero-emissions goal and various forms of hybrid propulsion are being developed to make further reductions possible, mostly using some form of battery storage to supplement conventional internal combustion engines.

Mobility needs its own focus – land, air and sea – surface and underwater

Mobility is a primary consideration for any warfighting force and for the ADF with such large land and sea areas to cover this is especially so.

Surface mobility for land vehicles is already under development with hydrogen, or ammonia as a source of hydrogen, and this will most likely be adopted for ADF land vehicles and for naval vessels not requiring high performance or long-range independent operations.

For high-performance naval vessels, and especially submarines, nuclear propulsion will be the preferred choice. Introduction of nuclear propulsion is being investigated by the Submarine Institute of Australia through its Nuclear Seminar series.

Air mobility may be suitable for electric energy but probably with limited performance and range. A more likely way ahead for aircraft is the use of synthetic fuels.

Synthetic fuels

Synthetic fuels are usable in much the same way as current fossil oil-based diesel and aviation fuels. The difference is they are manufactured and consumed by chemical processes in which the carbon content is added to create the fuel and then recovered in combustion to return through the cycle again.

Another synthetic fuel is methanol, requiring an integrated system described as follows: ‘The envisaged integrated shipboard installation combines a membrane reactor, a CO₂ capture system, CO₂ and methanol storage tanks, and hydrogen-capable reciprocating engine.’

Hydrogen and ammonia

Hydrogen is an ideal emissions-free fuel as it is burnt with an oxygen source to produce only water vapour as a carbon-free emission. However, hydrogen is an inconvenient material to transport in either liquefied or compressed gaseous form. For that reason, there is growing interest in use of ammonia a source of hydrogen in that it is a liquid at room temperatures and modest pressures and lacks carbon content, with only nitrogen as a by-product of hydrogen production.

Nuclear propulsion

Then there is nuclear propulsion in wide use for submarines and high-performance, long-endurance ships including ice breakers and aircraft carriers.

There is a popular myth in Australia that nuclear propulsion is not feasible until there is a nuclear industry, but that is disproven by the genesis of nuclear propulsion in the US where this occurred before the nuclear power stations that benefited from the nuclear submarine research and development and which even to this day employ many former nuclear submariners as watchkeepers in power stations.

There are many issues to be resolved for nuclear propulsion for the ADF, including repeal of legislative prohibitions on nuclear power and on adding value to Australian mined uranium to create nuclear fuel or to reprocess spent fuel and consign residual radioactive waste to approved geologically stable repositories.

However, nothing in the nuclear fuel cycle is dependent on commercial viability if it is needed for national security.

On the contrary, none of the nuclear fuel cycle steps including refuelling of submarine reactors is unique to military use and could all be employed for a nuclear shipping fleet of high speed merchant ships as well as larger Navy surface vessels.

Such investment in nuclear propulsion infrastructure is feasible, safe and within well-understood technological fields in which Australia is well versed through the Australian Nuclear Science and Technology Organisation (ANSTO) and the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA). The latter has some time ago published the regulations for port visits by nuclear-powered warships and these same provisions would apply to submarine construction in Osborne, South Australia, and for refuelling and defuelling at end-of-service life.

Roadmap for ADF mobility evolution

The roadmap for ADF mobility assurance then must include the urgent attention by Defence Science and Technology Group (DSTG) to understand the full range of R&D underway on alternatives to fossil fuels for all vehicles employed in ADF operations and sustainment, and then the prioritisation and investment in those more urgent technologies for ADF early adoption.

There probably isn’t much point at looking at electric vehicle batteries and motors, which are receiving significant investment from the commercial sector, and aircraft propulsion engines with synthetic fuels or electric propulsion may be beyond us.

Hydrogen and ammonia, on the other hand, are so fundamental that we should get up to full speed on the various approaches under development. Australia’s Chief Scientist Dr Alan Finkel is leading the Hydrogen Economy Roadmap and we need to ensure that ADF mobility is fully considered. The recent experience where battery investment for submarines is being pursued in isolation from battery development for renewable electricity generation should be an object lesson for how an integrated national approach must be taken.

Conclusions

The mobility for the Australian Defence Force vehicles of all types must be assured beyond the availability of oil or other fossil fuels. There are many developments underway that are of direct relevance and give cause for optimism that ADF mobility will be assured. But that will only happen with the full attention of DSTG and other research agencies to participate in the development of selected technologies in a timely manner.

Christopher Skinner is a former Navy engineer with extensive sea service and development experience ashore in defence and transportation domains. He is the editor of the Nuclear Propulsion Roadmap for Australia.