Why do transit agencies keep falling for the hydrogen bus myth?

Original Article ↗ Hacker News Discussion ↗

Hydrogen vs. Battery Buses in Practice

  • Many commenters argue hydrogen buses are intrinsically less efficient and more expensive per mile than battery‑electric, even when hydrogen is “green,” due to conversion, compression, transport, and fuel‑cell losses stacking up.
  • Case data cited (e.g., AC Transit) show:
    • Hydrogen infrastructure, fuel, and maintenance costing more than for battery buses.
    • Both hydrogen and battery buses still less reliable than diesel, but battery buses have the lowest per‑mile operating cost.
  • Others note hydrogen buses can, in theory, replace diesel 1:1 on range and refuel time, while early battery buses sometimes needed 2:1 fleet replacement or careful charging design. Critics respond that current BEB ranges and opportunity charging (at layover stops or depots) mostly solve this.

Hydrogen Production, Greenwashing, and Influence

  • Strong theme: grey and blue hydrogen (from fossil gas, with or without CCS) are framed as “green” but largely serve fossil‑fuel interests and prolong gas infrastructure.
  • Several see transit hydrogen pushes as driven by lobbying, conflicts of interest in industry‑linked research consortia, and political optics, not lifecycle economics.
  • Historical reference: US hydrogen initiatives in the 2000s are portrayed by some as a deliberate distraction from EVs; others dispute this or call it hindsight bias.

Battery Buses, Trolleybuses, and Grid Constraints

  • Many argue batteries have “won” for city buses: fixed routes, stop‑start driving, depot charging, and big vehicles mitigate weight concerns; noise and local air quality improvements are praised.
  • Counterpoints:
    • Hilly cities and cold climates can stress range and charging infrastructure.
    • Depot power upgrades (multi‑MW connections, substations) can be slow and capital‑intensive.
  • Trolleybuses are cited as technically excellent, especially on hills, but suffer from high wire infrastructure cost, NIMBYism, and inflexibility. Hybrid trolley‑battery buses are mentioned as a compromise.

Emissions and EV Effectiveness

  • Disagreement over “EVs just move the tailpipe”:
    • Some say EVs are only as green as the grid and short‑term just shift emissions to smokestacks.
    • Others cite lifecycle analyses showing EVs beat ICE even on fossil‑heavy grids, plus major gains in local air quality and their role as flexible load to enable more renewables.

Hybrids and Other Alternatives

  • Parallel hybrids (e.g., Toyota‑style power‑split) are praised as highly efficient and mechanically simpler than conventional transmissions; series hybrids and range‑extender concepts spark debate on complexity vs benefit.
  • CNG/biogas and LPG get some support as transitional fuels, but many see them as overtaken by battery buses.
  • A few advocate streetcars/trams as the “real” long‑term solution where demand is high enough.

Broader Hydrogen & Aviation Tangents

  • Hydrogen’s poor volumetric energy density, storage challenges, and pipeline embrittlement are repeatedly raised.
  • Electric aviation is viewed by many as limited to trainers and short hops for now; some point to emerging eVTOL and regional projects as counterexamples, but consensus is that long‑haul remains fossil‑based for the foreseeable future.