Air QualityEnvironment & ClimateFossil FuelsHeavy Duty & Off-highwayMarine & heavy dutySustainabilityThermoPower

How are heavy duty/off-highway, marine & aviation finding ways to transition to zero emissions?

By January 20, 2022 No Comments

With road transport accounting for approximately 10% of all global emissions, global shipping producing approximately 3% of global CO2 emissions & aviation approximately 12% of global emissions: the need to move to zero emissions & net zero is of paramount importance.

Passenger road vehicles

The transition to zero emissions road vehicles is not a new concept, but rather than the technology being designed for an elite customer base with costs for EV’s in particular being out of the financial scope of many average working families; the plans for zero emissions vehicles going forward are to make them more accessible to a much wider audience.

With many global cities having already become car free, ULEZ’s appearing in most major cities in the UK & many other global cities already planning to remove cars entirely; the investment in zero emissions public transport is also being ramped up.

Electric trams have been in operation for decades, but now we are seeing the investment into removing diesel buses & replacing with electric or hydrogen & the Taxi’s in London are slowly being replaced by electric.

Despite the pledges made at last year’s COP26, not all were in agreement of the focus being very much on the transition to electric passenger cars for example. The Sustainable Transport Alliance pointed out that ever more cars, however they’re powered, will mean more congestion. (1)

All EV’s require a lot of energy & materials in their construction & delivery to their end users, making it questionable if an EV can be an entirely net zero product. (1)

The alliance wanted to see countries shift away from electrifying cars to reducing their number, while making other forms of transport more attractive & less congested. (1)

The UK Government announced as part of it’s 10 point Green Industrial Revolution in November 2020 that from 2030 the UK will end the sale of new petrol & diesel cars & vans, 10 years earlier than planned. This poses the question, what plans do the UK Government have to extend this reach to heavy duty, marine & aviation?

It is no secret that although it has been relatively easy to electrify or hybridise passenger vehicles such as cars, small vans & public transport, including some trains; the heavy duty, off-highway, construction, marine & aviation sectors are still finding it a challenge to get to zero emissions.

With these sectors relying on hundreds of tonnes of machinery being able to either drive on roads, construction sites, at sea or in the air with established engine & fuel methods proving they have the power & longevity to maintain their capacity; how can these sectors find ways to reach the targets set under the Paris Agreement, by International Governments & uphold the pledges made at the 2021 COP26?

Heavy duty & off-highway

Despite the inherent challenges posed by the heavy duty sector, the UK Government confirmed on in November 2021 that all new heavy goods vehicles in the UK will be zero-emissions by 2040.

The UK will become the first country in the world to commit to phasing out new, non-zero emission heavy goods vehicles weighing 26 tonnes & under by 2035, with all new HGVs sold in the UK to be zero emission by 2040. (2)

This is a very ambitious target, with technology particularly in the heavy duty sector needing some considerable investment & development to still remain a viable competitor to the longevity of the traditional diesel engine.

Despite huge developments in electrification for heavy duty vehicles, the Automotive Council roadmaps for 2020 identified that different vehicle applications would still require different powertrain solutions based on their energy & power demands. (3)

Even though there have been considerable developments in battery electric off-highway vehicles in Europe & the roll out of highways with inbuilt pantograph power collectors to charge on board batteries; this is still very much in the development phase.

One such development is the Dolphin N2 Recuperated Split Cycle Engine. The Recuperated Split Cycle is an internal combustion engine, with all that implies in terms of low cost & ease of manufacture, that aims to compete with zero emission drivetrains. (4)

There are in fact two versions of the technology: ThermoPower® is a simplified system offering most of the air quality benefits and efficiency advantage versus advanced diesel engines in research; CryoPower® delivers ultimate efficiency & air quality by addition of Liquid Nitrogen or Air to its internal processes. (4)

The Dolphin N2 combustion system has already been demonstrated on methane gas (which can be made from wastes as a carbon-negative fuel), but Hydrogen is emerging as a leading contender for heavy duty road transport.

The Dolphin N2 partnership with the University of Brighton has allowed them to explore how Hydrogen might suit ThermoPowerTM using computer simulations, & the results looked good.


Eighteen states from across the world which represent over 40% of global aviation emissions, agreed at COP26 (2021) on an ambitious new aviation decarbonisation target.

It was announced at COP26 that 18 businesses & corporate customers in the aviation industry were aiming at a sustainable aviation fuel mix of 10% by 2030. In 2020 the sustainable fuel mix in aviation was only 0.1%.

With the new sustainable fuel in aviation, it would save 60M tonnes of C02 per year in the UK alone.


Container ships still currently & predominantly running on ‘bunker fuel’ produce carbon dioxide & black carbon, a fine particulate that can absorb a million times the energy of CO2.

Research & development around the globe is forging new ways to fuel commercial marine vessels & in doing so reduce emissions to the levels set by the IMO. The challenges this poses are considerable, as there is no single economically viable decarbonised solution for heavy duty vehicles & vessels.

Although hydrogen is being hailed as a heavy duty future sustainable fuel in certain sectors, it is Ammonia (NH3) which is being developed as an alternative to HFO in the marine sector & as a zero emissions potential net zero game changer.

Last November at COP26, 19 governments pledged to support the investment in & establishment of zero emission shipping corridors – zero-emission shipping routes between 2 ports. (5) This would include zero emission shipping technologies being deployed & adopting alternative fuel & charging infrastructures in ports.

There is still a considerable way to go to find sustainable & economically feasible alternative fuel sources & adaptable powertrains for the heavy duty, off-highway, marine & aviation sectors.

Written & cited by Katy Mason for & on behalf of Dolphin N2