Four different hydrogen technologies. Only one of them is this.
Most confusion about hydrogen on vehicles — and most of the scepticism — comes from four unrelated technologies being discussed as though they were one. Here is the distinction, including where our own product genuinely sits and what it does not do.
What is the difference between these hydrogen technologies?
Combustion enhancement adds a small on-demand hydrogen fraction to the intake of an engine still running on diesel or petrol — a reversible four-figure retrofit with no hydrogen storage. H2ICE burns hydrogen as the primary fuel in a purpose-built or deeply converted engine. An FCEV converts hydrogen to electricity in a fuel cell and has no engine at all. On-board chemical generation releases hydrogen from a consumable reagent instead of from water. We supply combustion enhancement only.
- Enhancement: diesel or petrol unchanged, gas made on demand from water, nothing stored
- H2ICE: hydrogen is the fuel, 350–700 bar storage, new or converted engine
- FCEV: hydrogen becomes electricity, electric drivetrain, no combustion
- Chemical generation: hydrogen from a consumable reagent, with a by-product to manage
- Only enhancement works on Australia's existing fuel network today
- Enhancement asks the least and delivers the least — a modest efficiency change, not a fuel switch
- We supply
- Enhancement only
- Storage on vehicle
- None
- Engine mods
- None — reversible
- Range
- HydroHub™ A-450 – D-900
What each one actually is.
Hydrogen combustion enhancement
This is usA small on-demand hydrogen and oxygen fraction is drawn into the intake air of an otherwise unmodified diesel or petrol engine. The engine keeps running on its normal fuel; the gas is a combustion aid.
- Primary fuel
- Diesel or petrol, unchanged
- Hydrogen storage
- None — gas generated on demand while running
- Engine change
- Unmodified, fully reversible retrofit
- Refuelling
- Existing diesel or petrol network; deionised water top-ups
- Order of cost
- Retrofit hardware, four figures per unit
The honest limitation: Improvement is modest and conditional. The published literature supports single-digit to low or mid-teen efficiency changes, dependent on engine, duty cycle and baseline condition.
Hydrogen internal combustion engine (H2ICE)
A purpose-built or heavily converted piston engine that burns hydrogen as its primary fuel, either exclusively or in a high-fraction dual-fuel arrangement.
- Primary fuel
- Hydrogen as the primary fuel
- Hydrogen storage
- High-pressure cylinders (typically 350–700 bar) on the vehicle
- Engine change
- New engine or deep conversion — injection, ignition, materials
- Refuelling
- Dedicated hydrogen refuelling station
- Order of cost
- New vehicle or major conversion programme, six figures upward
The honest limitation: A genuine decarbonisation pathway, but it depends on refuelling infrastructure that barely exists on Australian freight corridors today.
Fuel cell electric vehicle (FCEV)
Hydrogen is converted electrochemically to electricity in a fuel cell stack, which drives electric traction motors. There is no combustion at all.
- Primary fuel
- Hydrogen, converted to electricity
- Hydrogen storage
- High-pressure cylinders plus a traction battery
- Engine change
- No engine — electric drivetrain
- Refuelling
- Dedicated hydrogen refuelling station
- Order of cost
- New vehicle purchase, six figures upward
The honest limitation: Highest efficiency of the hydrogen pathways and zero tailpipe combustion products, but the most capital-intensive and the most infrastructure-dependent.
On-board chemical hydrogen generation
Hydrogen is released by a chemical reaction on the vehicle — for example a metal or hydride reacting with a consumable reagent — rather than by electrolysis of water.
- Primary fuel
- Diesel or petrol plus a consumable reagent
- Hydrogen storage
- Reagent and reaction by-product both handled on the vehicle
- Engine change
- Unmodified engine in most designs
- Refuelling
- Existing fuel network plus a reagent supply chain
- Order of cost
- Hardware plus an ongoing consumable reagent cost
The honest limitation: Introduces a consumable supply chain and a by-product disposal question that water electrolysis does not have. Evaluate the reagent logistics before the hardware.
Three practical consequences.
Safety profile
Storage is the dividing line. H2ICE and FCEV installations carry high-pressure hydrogen and are engineered around that. An enhancement unit generates gas only while the engine runs and holds no inventory, so the hazard analysis is a different exercise entirely.
Infrastructure dependency
Enhancement runs on the diesel you already buy. H2ICE and FCEV need a hydrogen refuelling station within operational range — which, on most Australian freight and mining corridors, is the binding constraint rather than the vehicle.
Expectation setting
Because a fuel switch changes everything and an intake additive changes a little, category confusion is exactly how unrealistic percentage claims spread. Judge an enhancement product against modest, measured expectations.
Continue with the category we supply.
- · How it works — the gas path and the established physics, with diagrams.
- · PEM vs alkaline — the two electrolyser types sold into this market.
- · Evidence review — the published literature and the Australian Consumer Law context.
- · Compare HydroHub systems — pick a unit by displacement and duty cycle.
No projected, typical or expected fuel-saving figure is published. Actual results vary materially with engine condition, duty cycle, load profile, fuel quality, installation and operating conditions. A controlled field evaluation on your own equipment, with baseline data captured before installation, is required before any commercial projection.
Questions.
Is a hydrogen combustion enhancement system the same as a hydrogen car?
- No. A hydrogen car — whether H2ICE or fuel cell — runs on hydrogen as its energy source, carries it in high-pressure cylinders, and needs a hydrogen refuelling station. A combustion enhancement system keeps the engine running on diesel or petrol and generates a small gas fraction on demand from deionised water. It stores nothing, changes no engine internals, and uses your existing fuel network.
Which technology do you supply?
- Hydrogen combustion enhancement only. The HydroHub™ range — A-450, A-675, A-900, H-Power and D-900 — is PEM electrolyser hardware fitted to existing diesel and petrol engines. We do not sell H2ICE conversions, fuel cell vehicles, or chemical hydrogen generation systems.
Why choose enhancement over converting to hydrogen?
- Cost and infrastructure. Enhancement is a four-figure reversible retrofit that uses fuel you can already buy anywhere in Australia. H2ICE and FCEV are six-figure vehicle decisions that depend on refuelling infrastructure not yet present on most Australian freight routes. Enhancement asks less and, honestly, delivers less — a modest efficiency change rather than a fuel switch.
Is hydrogen stored on the vehicle in an enhancement system?
- No. Gas is produced only while the engine runs and is consumed immediately in the intake. There is no pressurised cylinder and no accumulated volume, which is the main reason the safety profile differs from that of an H2ICE or FCEV installation.
Do any of these make an engine emissions-compliant?
- An enhancement retrofit does not. We make no emissions-compliance or certification claim for it, and fitting one does not alter an engine's certified emissions status. FCEV and H2ICE compliance is a matter for the vehicle manufacturer's own certification.
Retrofit combustion enhancement, by application.
These are the fleets where a reversible retrofit is being considered against an engine replacement or a fuel-cell program.
Mining fleets →
Haul trucks, articulated dumpers, production dozers, loaders, drill rigs and camp gensets. Dust, pit heat and remote servicing decide as much as displacement does, and carted fuel changes what a percentage is worth.
Marine →
Workboats, charter and dive vessels, ferries and ship's service gensets. Nothing is stored aboard — gas is made on demand — which is normally a surveyor's first question.
Rail & locomotive →
Two duty profiles in one sector: mainline locomotives on long steady high-load hours, and shunting, yard-switching and rail-maintenance plant on stop-start duty with heavy idle.
Public transport & bus →
Urban route buses, coaches and midibuses. Stop-start duty with high idle fractions, depot-based servicing and public-facing smoke visibility all matter here.
Generator sets →
Stationary diesel gensets on continuous and prime duty from 100–500 kVA — remote camps, telecom sites and standby plant fed from the set's own starting battery.
Agriculture →
Tractors, headers, sprayers, farm trucks and irrigation pump sets. Seasonal idle periods, on-farm water quality and distance from a dealer shape the specification.
All applications — the full vertical index →·Partner program →
Continue reading.
Hydrogen combustion enhancement
What it is, how PEM gas reaches the cylinder, and what it does not do.
Engine performance improvement
Flame speed, burn completeness and load response on diesel engines.
Fuel efficiency
How to baseline and measure litres per 100 km or litres per hour.
Emissions reduction
Soot, particulate and unburnt-fuel behaviour, and how to test it.
Visible smoke reduction
Smoke opacity findings per study, with the NOx trade-off disclosed.
Remote-site fuel logistics cost
Landed cost versus pump price, and why the same percentage moves more money.
Generator-set classes
Camp, prime, standby, rental, telecom, irrigation and ship's service sets compared.
Idle & part-load duty cycles
Reefers, camp gensets and high-idle plant — where the literature reports most room.
Hydrogen with biodiesel blends
Per-study findings for hydrogen enrichment on biodiesel, NOx disclosed.
Installation guide
Nine-step fitting sequence: mounting, wiring, gas line, commissioning.
Safety & compliance
On-demand gas, no storage, alarms, shutdowns and reversibility.
Troubleshooting
Alarms, low gas output, water quality and no-start diagnostics.
Case studies & field results
Published operator data and trial methodology.
Compare PEM systems
A-450 to DH-Power side by side: displacement, output, current draw.
Does it actually work? Evidence review
The published literature, the FTC/EPA history and the ACL context.
How it works
Gas path and established physics, explained with diagrams.
PEM vs alkaline
Membrane on water versus caustic KOH: servicing, purity, cost.
Sizing combined gas
Why PEM and alkaline gas-volume benchmarks are not interchangeable for ICE sizing.
Compared with Hydrogen Fuel Systems
Honest comparison with the Perth-based Gen alkaline range.
Compared with H2i Technology
Hardware, pricing and evidence transparency versus the Victorian supplier.
Compared with dynaCERT HydraGEN
PEM versus alkaline, published price versus dealer quote, Verra versus ACCU.
Compared with HYDI
The South Australian manufacturer: UniSA testing, field history and quote path.
AU installation, warranty & safety
VSB 14 and VSB 6, ACL guarantees and documentation to keep.
Mining fleets
Haul trucks, dozers, drill rigs and site gensets: unit selection and dust.
Marine
Workboats, charter, fishing and ship's service gensets — no gas stored aboard.
Agriculture
Tractors, headers, pump sets and farm trucks across seasonal duty.
FAQ
Answers on fitment, water, warranty, freight and duty cycles.