Solid oxide fuel cells (SOFCs) operate at high temperatures—typically 600–850 °C—and can deliver higher electrical efficiencies than low-temperature PEM fuel cells, especially in combined heat and power configurations. For heavy-duty trucks, SOFCs promise efficient conversion of hydrogen, ammonia, or even reformate fuels into electricity, potentially enabling smaller tanks or longer range. The challenge is durability: thermal cycling, vibrations, and start–stop operation all stress SOFC stacks. At Energy Solutions, we evaluate whether SOFCs can move from stationary applications into freight trucks, and under what duty cycles and business models they make sense.
Solid oxide fuel cells use a ceramic electrolyte that conducts oxygen ions at high temperatures. Oxygen from air is reduced at the cathode, travels through the solid electrolyte, and oxidises fuel at the anode, generating electricity and heat. Key characteristics include:
Energy Solutions benchmarks are based on published SOFC performance data, stationary system experience, prototype truck concepts, and internal duty-cycle models. We compare SOFC and PEM fuel cell trucks on tank-to-wheel efficiency, durability, and TCO under long-haul and regional scenarios.
The table below summarises stylised benchmarks for heavy-duty truck applications.
| Technology | Typical Electrical Efficiency (Tank-to-DC, %) | System Power Density (kW/kg, stack+BoP) | Target Lifetime (operating hours) |
|---|---|---|---|
| Diesel ICE | ~40–45 (tank-to-wheel) | High (mature) | 25,000–35,000+ |
| PEM fuel cell (HD truck) | ~45–55 | Moderate | 20,000–30,000 (stack target) |
| SOFC (truck concept) | ~55–65 (steady-state) | Lower (heavier system) | 10,000–20,000 (current targets) |
Source: Energy Solutions modelling; SOFC values assume steady-state operation at design load.
Integrating SOFCs into trucks is as much a thermal and mechanical engineering challenge as an electrochemical one. High operating temperatures and slower start-up/shut-down times mean that SOFCs favour relatively steady operation, often paired with batteries and potentially a small PEM stack for transient power.
Source: Energy Solutions concept allocation of average vs peak power between SOFC stack and battery.
The TCO of SOFC trucks depends on stack cost, replacement intervals, and hydrogen use. Higher efficiency can offset higher capital costs if stacks last long enough and hydrogen prices remain elevated.
| Powertrain | Vehicle Capex (Diesel = 1) | Hydrogen Consumption (kg/100 km) | Hydrogen Cost (Index, PEM = 1) | Stack Replacement Cost Impact |
|---|---|---|---|---|
| PEM fuel cell truck | ~2.2–2.5 | 8–10 | 1.0 | Moderate; single replacement often assumed. |
| SOFC truck concept | ~2.5–3.0 | 6–8 | 0.8–0.9 (less H₂ used) | Higher; uncertain replacement frequency. |
Source: Energy Solutions TCO analysis; assumes hydrogen at 4–8 EUR/kg and learning curve effects.
SOFC trucks introduce a layer of thermal and materials complexity that many fleet operators may be reluctant to accept. High-temperature stacks, insulation, and start-up regimes all add failure modes relative to PEMFC or battery systems. If durability targets are not met in the field, operators risk frequent and costly stack replacements, eroding any efficiency gains.
From a portfolio perspective, some investors may prefer to focus on scaling PEMFC and BEV platforms, which already have substantial industrial momentum, rather than backing another fuel cell architecture with uncertain long-term learning curves. SOFC may still find a place, but likely in niches where its high efficiency and fuel flexibility clearly outweigh added complexity.
By 2030, SOFC trucks are likely to remain in the demonstration and early commercial category. By 2035, they could account for a modest share of hydrogen truck fleets in specific corridors—particularly where steady, long-haul duty cycles and high hydrogen prices make efficiency gains especially valuable.
| Scenario | PEMFC Trucks (%) | SOFC Trucks (%) | Comments |
|---|---|---|---|
| Conservative | 95–100 | 0–5 | SOFC remains largely experimental. |
| Base case | 80–90 | 10–20 | SOFC finds niches in specific corridors or OEM portfolios. |
| SOFC-forward | 60–80 | 20–40 | Strong durability improvements and targeted policy support. |
Source: Energy Solutions hydrogen truck scenarios; shares expressed as share of FCEV stock.
SOFCs can, in principle, deliver higher electrical efficiencies and greater fuel flexibility than PEM fuel cells, especially in steady-state operation. This can reduce hydrogen consumption and enable the use of alternative fuels such as ammonia-derived hydrogen, but comes at the cost of higher system complexity and durability challenges.
SOFCs favour long, steady operating periods with limited start–stop cycling, such as hub-to-hub long-haul routes. Stop–go urban delivery cycles with frequent shutdowns are less suitable due to thermal stresses and slower start-up times.
Durability is critical. If SOFC stacks need replacement too frequently, the total cost of ownership can quickly exceed that of PEMFC or diesel trucks, even with higher efficiency. Achieving lifetimes comparable to or better than PEM stacks is therefore a key R&D focus.