Volvo Trucks has begun road tests for heavy-duty trucks with hydrogen combustion engines. According to the company, series production is planned before 2030.
What is new here is not so much the energy carrier as the technical approach: instead of converting hydrogen into electricity in a fuel cell, it is used directly as a fuel in an internal combustion engine.
Refueling a hydrogen-powered truck (Source: Volvo Trukcs)
What’s different here?
Hydrogen engines are not new in principle. However, Volvo is relying on so-called HPDI technology (High Pressure Direct Injection). In this process, a small amount of ignition fuel is injected before hydrogen is supplied at high pressure.
The goal:
- higher efficiency,
- more power,
- operation similar to diesel.
According to Volvo, the system is based on technology already in use in gas-powered trucks.
Context: an alternative to the fuel cell
Two approaches to hydrogen currently dominate the industry:
- Fuel cell (e.g. Daimler Truck, Hyundai)
- Internal combustion engine (including Volvo, and occasionally other manufacturers in tests)
The difference:
- Fuel cell generates electricity
- Internal combustion engine uses hydrogen directly as fuel
The key advantage of combustion lies above all in its real-world practicality: proven technology, familiar maintenance, fast refueling.
Where it matters
Volvo sees the main use case in long-haul transport – i.e., where battery-electric trucks hit their limits:
- long distances
- short downtime
- lack of charging infrastructure
With green hydrogen, the vehicles could, according to the company, be operated almost CO2-neutrally and are considered emissions-free from a regulatory perspective.
Several technologies remain in the race
In parallel, Volvo continues to focus on battery-electric and fuel-cell trucks. This keeps the market technology-neutral: a single, uniform solution for zero-emission heavy-duty transport has not yet been decided. The hydrogen combustion engine is not an entirely new approach, but it is a clear counterproposal to the fuel cell; the decisive factor will be whether it proves itself in everyday operation. For road freight, that practical proof is critical because long-distance operations are where decarbonisation technologies face the toughest constraints.
