Electric Propulsion's Dirty Secret: Why Lithium Can't Fly (Or Float) Profitably

Limits of Batteries for Aviation and Shipping

• Many commenters agree that with current lithium-ion energy density (tens of times worse than jet fuel per kg), long‑haul aircraft and ocean‑going cargo ships are not realistically electrifiable.
• Fixed battery weight (unlike fuel that burns off) hurts aircraft efficiency and landing performance; some argue this alone keeps large electric airliners impractical.
• Electric VTOL and air taxis are seen as especially energy‑hungry (2.5–3× per mile vs conventional flight), further limiting range and economics.
• Some highlight that marine drag and constant high power demand make pure battery ships challenging beyond short routes.

Where Electric Propulsion Does Make Sense

• Several note existing or planned electric ferries, tugs, and short‑range tourist or commuter boats that already pencil out on cost and noise/emissions.
• Small training aircraft and very short‑haul routes are cited as feasible early niches for electric planes.
• Many emphasize that electric road vehicles (cars, scooters, e‑bikes) are already economically and technically competitive for most everyday use.

Alternative Fuels and Non‑Battery Options

• Strong interest in synthetic hydrocarbons, methanol‑to‑kerosene, ammonia, hydrogen, and biofuels as “drop‑in” or near‑drop‑in solutions for aviation and shipping, powered by cheap clean electricity.
• Skeptics argue e‑fuels are only 10–15% efficient “round‑trip” and would require enormous extra generation capacity; supporters counter with falling renewable costs.
• Wind‑assist and modern sail concepts for cargo ships, plus slow steaming, are discussed as partial decarbonization paths.
• Nuclear marine propulsion is seen as technically viable but hampered by capital cost, regulation, crew requirements, and security/political concerns.

Economics, Policy, and Infrastructure

• Several argue that aviation appears “cheap” because fuel is tax‑favored; adding fuel and CO₂ taxes would push more travel to rail, especially if high‑speed rail were expanded despite high upfront costs.
• Others stress that regulation and pricing (e.g., airport bans for fossil planes, special electricity tariffs) could rapidly change today’s economics.
• There’s debate over whether long‑distance flying will become an elite luxury vs remaining accessible via synthetic fuels and policy choices.

Critiques of the Article’s Claims and Framing

• Multiple commenters say the piece uses clickbait framing (“dirty secret”), straw‑mans no‑one’s position, and mixes up power vs energy and cost metrics.
• Specific numbers (e.g., $5/kWh scooter electricity, lifecycle cost per kWh, “70% of energy before the vehicle moves”) are challenged as off by factors of 10 or based on misapplied LCOE concepts.
• Some track cited references and find broken links, misattributed studies, or selective interpretations; in several back‑of‑the‑envelope recalculations, EVs come out cheaper and cleaner than portrayed.
• Critics also fault the author for lumping aviation and all marine vessels together, ignoring that short‑haul ferries and small boats have very different constraints from intercontinental jets or container ships.

Battery Technology Trajectory

• One side notes physical/chemical limits on lithium‑ion and estimates that matching jet fuel energy density would take many decades, if ever.
• Others point out that battery cost has plummeted, density has roughly doubled in a decade, and modest further gains plus new chemistries could steadily expand the set of viable electric niches—even if jumbo jets never go fully electric.