Gravity can replace diesel fuel for EV trains and trucks

The news: Swiss and Australian companies are showing how gravity can fully power specialized EVs carrying heavy cargo.

Swiss EV company eMining AG manufactures the eDumper, a 65-ton dump truck that has electric motors, batteries, and cooling machinery in place of a diesel engine and fuel tank.

  • The eDumper, which hauls 70-ton loads of lime and rocks at a quarry in Switzerland, rarely needs recharging and saves between 11,000 and 22,000 gallons of diesel fuel annually, per NBC.
  • Testing shows that the eDumper—reportedly the largest EV in the world—generates enough electricity going downhill to power it back uphill.

Gravity can also power trains. Australian mining company Fortescue plans to build Infinity Trains that can generate enough electricity while carrying loads of iron ore from the Outback to power the return trip.

  • The company is eyeing four routes suitable for powering the trains by gravity, with operations expected before 2030.
  • Some routes will reportedly produce surplus energy that the company will use for other purposes.

Here’s how it works: The gravity fuel system exploits a special feature commonly found in EVs—regenerative braking.

  • Regenerative braking means electric motors allow the kinetic energy of vehicle motion to transform into electricity during deceleration or when traveling downhill.
  • Though it’s generally not nearly enough to power vehicles, it can help extend driving range.
  • Gravity-fueled EVs are designed to harness regenerative braking potential by relying on heavy cargo to drive more kinetic energy downhill—–enough to fully power the vehicle back uphill, sometimes with energy to spare.
  • According to eMining AG chief executive Roger Miauton, a 10% grade is sufficient to make conventional recharging unnecessary, per NBC.

The gravity of the situation: Although the technology depends on heavy cargo and a sufficient incline to completely cover energy demands, it could help transform the clean energy sector in many ways.

  • As pollution from diesel vehicles kills thousands every year globally, this technology could replace existing fleets in certain industries, extend people’s lives, and reduce carbon emissions.
  • The gravity system provides a potentially cheaper alternative to green hydrogen for powering heavy vehicles for industries like mining.
  • It could also work in conjunction with a hydrogen-electric hybrid system to boost efficiency in places where an adequate gradient isn’t guaranteed.
  • Additionally, it could potentially power the burgeoning electric-locomotive sector for suitable routes.
  • The technology could also spur further regenerative braking innovations for consumer EVs.
  • Furthermore, EV truck and train gravity systems could work like the Energy Vault, in which surplus energy is stored in renewable energy system batteries.