Weight reduction

Future fuel cell systems for rail vehicles could be a much lighter option than diesel-electric systems.

Costs

Investement costs are far too high.

Risk for developers

• R&D in fuel cells is risky for industry (especially railway manufacturers) since development costs before mass production are particularly high.
• Development potential uncertain: Some experts hold that hydrogen technology is over 60 years old and given such a long development period has not evolved sufficiently in order to justify expensive R&D efforts.

Technological shortcomings

• Power density is far from sufficient for most railway traction applications.
• liability to defect and lifetime: one reason for liability to defect lies in the high number of internal interconnections between fuel cells in the stack. Lifetime of present fuel cells is ~ 5000 hours.
• Fuel supply and storage: hydrogen storage unsatisfactory, progress too slow in this area.
• Efficiency: Total efficiency of fuel cell system must be improved in order to become a diesel alternative.

Range

Present technology could lead to range problems due to low fuel densities.

Environmental

If hydrogen from fossil sources is used and assuming present efficiencies of fuel cells, environmental balance of fuel cells is worse or at best equal as for diesel traction (cf. Environmental criteria – Other environmental impact).

Infrastructure transition

New infrastructure needed. Gaseous fuel requires more careful handling than diesel.

Interoperability

Problematic as long as fuel supply infrastructure is not fully deployed.

Safety

Explosiveness of hydrogen-oxygen mixtures. This problem can be considered as principally solved.

There are restrictions concerning fuel cell powered vehicles in tunnels and underground service.

Technological inertia

Scepticism rules in both railway and manufacturing companies to deviate from conventional and successfully technology.

• Research funding (national or European)
• Strict emission regulations
• Clear regulations (emissions, safety etc.) providing a good planning basis
• Successful developments in automotive sector (both technological and market).

A co-operation and co-ordination of European railways could prepare a common view on fuel cells and set the basis for a later introduction.