The risks of hydrogen cars

Hydrogen cars face notable risks: flammability of high‑pressure hydrogen, rare but consequential refueling incidents, sparse and sometimes unreliable fueling infrastructure, high and volatile fuel prices, upstream emissions and leakage that can undermine climate benefits, and practical issues like cold-weather performance, limited cargo space, and end‑of‑life handling of pressure vessels. While modern fuel‑cell vehicles (FCEVs) are engineered with robust safety systems and pass stringent crash tests, these factors collectively constrain mass adoption today.

Safety and engineering risks

Hydrogen is an energy-dense but challenging fuel. Its properties and the pressures used in on‑board storage introduce unique hazards that differ from gasoline and battery-electric systems.

• Flammability and invisible flames: Hydrogen ignites easily, burns with a low‑radiant, often nearly invisible flame in daylight, and rises quickly, which can reduce ground-level exposure but complicate detection during a fire.
• High-pressure storage: Light-duty FCEVs typically store hydrogen at up to 700 bar (about 10,000 psi). A damaged line or valve can produce high‑velocity jets capable of ignition; tanks use thermal pressure relief devices (TPRDs) to vent safely, but jet fires can still be intense.
• Leak detection challenge: Hydrogen is colorless and odorless; common odorants used in natural gas would poison fuel cells, so detection relies on sensors and ventilation, not smell.
• Material embrittlement and permeation: Hydrogen can diffuse into some metals and cause embrittlement over time; while modern tanks are composite and designed to standards, fittings, pipelines, and station components require careful material selection and inspection.
• Garage and enclosed-space risk: Hydrogen accumulates near ceilings; codes require ventilation and sensors in enclosed parking and stations to prevent explosive mixtures.
• Refueling station incidents, though rare, can be high-impact: Events such as the 2019 Norwegian station explosion highlighted how system faults can cascade; industry has since tightened protocols, but residual risk remains.
• Emergency response complexity: First responders need specialized training (e.g., recognizing invisible flames, handling TPRDs); standard tactics differ from gasoline or EV battery fires.

Overall, regulatory standards (e.g., SAE J2579 for on-board fuel systems, NFPA 2 for hydrogen technologies) and automaker designs have made FCEVs notably safe in normal use, yet the combination of high-pressure gas and detection challenges requires rigorous maintenance, proper ventilation, and well-trained operators.

Infrastructure and reliability risks

Fueling networks for light‑duty hydrogen cars are still sparse and can be fragile, creating availability and reliability risks that affect day‑to‑day usability.

• Limited station density: As of late 2024, the U.S. has only dozens of retail stations, largely clustered in California (roughly 50–60 open at any time). Germany has around 100, and Japan roughly 160–170; most other regions have very few.
• Uptime challenges: Stations may experience outages due to compressor faults, hydrogen supply interruptions, or maintenance. Drivers can face queues or find stations offline.
• Supply chain fragility: Deliveries of compressed or liquefied hydrogen depend on specialized trailers and, for liquid, energy‑intensive liquefaction with boil‑off losses; disruptions ripple quickly to retail pumps.
• Standardization and compatibility: Light‑duty cars require 70 MPa fueling per SAE J2601 protocols; not all stations or dispensers support every profile, and temperature compensation must be reliable to ensure full fills.
• No practical home refueling: Unlike BEVs, drivers cannot easily refuel at home, making them fully dependent on public infrastructure.

Until networks expand and achieve consistently high uptime, infrastructure risk remains one of the most visible barriers to owning a hydrogen car for daily use.

Economic and market risks

Hydrogen cars can impose higher and more volatile operating costs, and the market’s limited scale adds uncertainty for buyers.

• Fuel price volatility and cost: Retail hydrogen in California has often ranged around $20–$30 per kilogram in recent years. With typical FCEV efficiency near 60–70 miles per kg, that’s roughly $0.30–$0.50 per mile—often several times the electricity cost per mile for BEVs and usually higher than efficient hybrids.
• Vehicle and component costs: Fuel-cell stacks use precious metals (platinum-group), and 700‑bar tanks are expensive; while costs are falling, low volumes keep sticker prices and parts costs elevated.
• Resale value and support risk: A small, regionally concentrated market can depress resale values and complicate service access if manufacturers or station operators change course.
• Policy dependence: Incentives and public funding heavily influence station rollout and TCO. Shifts in policy or budgets can stall expansion or affect fuel prices.

These economic pressures can outweigh advantages like fast refueling, especially where electricity is inexpensive and public charging is widespread.

Environmental and climate risks

Hydrogen’s climate benefit depends on how it’s produced, transported, and contained. Leakage and upstream emissions can erode or even negate advantages over efficient combustion or battery-electric options.

• Production pathway matters: “Gray” hydrogen from natural gas has substantial CO₂ emissions; “blue” hydrogen adds carbon capture but still depends on capture rates and methane leakage; “green” hydrogen from renewable electrolysis is low‑carbon but currently limited and energy‑intensive.
• Hydrogen leakage warms the climate indirectly: Escaped H₂ alters atmospheric chemistry and lengthens methane’s lifetime. Recent studies estimate a 20‑year global warming potential around 30–40 and about 10–12 over 100 years. High leakage rates across the supply chain can significantly diminish climate gains.
• Methane leakage in gas supply: For blue or gray hydrogen, upstream methane leakage above a few percent can negate benefits versus direct electrification, even with carbon capture.
• Efficiency penalty: Well‑to‑wheel efficiency for road transport via hydrogen is typically 25–35%, versus roughly 70–90% for battery-electric. That implies more renewable generation is needed to move the same vehicle mile with hydrogen, raising system-wide environmental and cost burdens.
• Local air pollutants: Fuel-cell vehicles emit only water vapor at the tailpipe; however, hydrogen burned in internal combustion engines (a separate technology) can produce NOx without careful control.
• Water and resource use: Electrolysis needs deionized water and electricity; scaling green hydrogen can add regional water and land-use pressures, depending on renewables siting.

In short, hydrogen cars can be very clean in operation, but their net climate impact hinges on low-leakage supply chains and genuinely low‑carbon hydrogen—which are not yet universal.

Performance and usability risks

Real‑world use introduces practical considerations that may not be obvious from spec sheets.

• Cold-weather behavior: Proton-exchange membrane fuel cells must manage water and can face cold-start penalties; modern systems can start well below freezing but with energy overhead and potential durability trade-offs over time.
• Space and weight trade-offs: Cylindrical 700‑bar tanks eat into trunk or cabin volume; packaging can reduce cargo flexibility compared with similarly sized BEVs or hybrids.
• Component lifespan: Stacks have finite lifetimes (measured in thousands of operating hours), and tanks typically have regulatory service lives around 15 years; replacements are costly.
• Service network density: Fewer trained technicians and authorized service centers can mean longer waits or travel for specialized repairs.

These usability factors don’t preclude ownership but can be decisive for households needing space flexibility, cold-climate reliability, or easy service access.

Risk mitigation and what drivers can do

For those considering a hydrogen car, practical steps can reduce exposure to the most common risks.

1. Verify fueling access: Use official station maps and live-status apps to confirm operational sites on your routes and near your home and workplace.
2. Check fuel contract terms: Some leases include hydrogen; understand caps, pricing, and station networks covered.
3. Learn fueling protocol: Follow SAE J2601-compliant procedures, ensure the nozzle is clean and latched, and stand clear during venting.
4. Park with ventilation in mind: Prefer open or well-ventilated areas; heed any building or garage restrictions for hydrogen vehicles.
5. Stay current on recalls and software updates: Fuel-system and sensor updates matter; enroll in automaker alerts.
6. Ask about hydrogen origin: If possible, choose suppliers offering certified low-carbon hydrogen to minimize lifecycle emissions.
7. Plan for service life: Understand stack and tank warranties, service intervals, and end‑of‑life procedures before purchase.

These measures won’t eliminate systemic risks like network fragility or fuel price volatility, but they can materially improve day‑to‑day reliability and safety.

Outlook

Governments and industry are investing in lower‑carbon hydrogen production, leakage monitoring, and safer, more reliable stations. Still, near‑term momentum for light‑duty passenger transport favors battery-electric vehicles due to higher efficiency, broader infrastructure, and lower operating costs. Hydrogen is more likely to find its strongest foothold in heavy-duty, long‑range, or industrial niches where batteries are challenged—while the risks and costs for consumer cars will take time to ameliorate.

Summary

Hydrogen cars are engineered to be safe but carry distinct risks: flammable high‑pressure fuel and specialized emergency response needs; sparse, outage‑prone fueling infrastructure; high and volatile fuel costs; and environmental uncertainties tied to production emissions and leakage. Practical drawbacks—cold-weather penalties, space trade-offs, and component lifetimes—add to the picture. For most drivers today, these risks outweigh benefits, though targeted use cases may still justify FCEVs as the technology and supply chains mature.