Most heavy trucks should be fully electric, using a combination of batteries
and catenary electrification, but heavy trucks requiring very long
unsupported range will need chemical fuels. Hydrogen is the key to storing
renewably generated electricity chemically. At the scale of heavy trucks,
compressed hydrogen can match the specific energy of diesel, but its energy
density is five times lower, limiting the range to around 2,000 km. Scaling
green hydrogen production and addressing leakage must be priorities.
Hydrogen-derived electrofuels—or “e-fuels”—have the potential to scale, and
while the economic comparison currently has unknowns, clean air
considerations have gained new importance. The limited supply of bioenergy
should be reserved for critical applications, such as bioenergy with carbon
capture and storage (BECCS), aviation, shipping, and road freight in the
most remote locations. Additionally, there are some reasons to prefer
ethanol or methanol to diesel-type fuels as they are inherently clean
burning, more easily synthesized, and more readily produced from cellulosic
sources.