Electric vehicles can generate electricity while carrying loads downhill

Tuesday, May 24th, 2022

Under the right conditions — going far enough downhill at enough of an angle with a heavy load — electric vehicles can generate a useful amount of energy:

Miauton’s company manufactures the eDumper, a 65-ton dump truck that’s said to be the world’s largest electric vehicle. Its diesel engine and fuel tank have been replaced with electric motors, batteries and cooling machinery, and it’s now working at a quarry near Biel in Switzerland, hauling 70-ton loads of lime and rocks down a mountainside.

Thanks to the expense of the high-tech systems, an eDumper costs about twice as much as a diesel-powered truck. But it never needs any fuel — a savings of between 11,000 and 22,000 gallons of diesel a year, along with its carbon emissions — and it almost never needs recharging. Test drives show it generates about as much electricity going down as it uses going up. Miauton said the company is now making three more eDumpers for mines in Germany, and it has plans for even larger electric dump trucks.

The concept of making electricity on a downhill run will soon get an even bigger boost. The Australian mining company Fortescue, a major producer of iron ore, announced in March that it will build “Infinity Trains” to generate electricity while carrying loads of ore from mines in the Outback.

The company currently runs 16 trains in Western Australia driven by 54 locomotives that use a total of around 20 million gallons of diesel fuel every year. Each train has up to 244 cars. They can be almost two miles long and carry more than 37,000 tons of ore.

Fortescue chief executive Elizabeth Gaines said four routes from mines in the inland Pilbara region are sufficiently uphill of their final destination — Port Hedland on the northern coast — that they’re suitable for Infinity Trains. The company plans to have them working on all four routes before 2030 by developing the dynamic braking feature many locomotives already have to convert gravity into electricity, she said in an email. Some routes will generate even more energy than they need for the return trip, and the company will use the extra electricity elsewhere in its operations.

The most innovative proposal for making electricity from gravity may be electric truck hydropower. According to a study published in March, a fleet of electric trucks filled with water high in the mountains can generate electricity as they travel downhill on regular roads. The empty trucks can then drive back for more water, or be used elsewhere.

Study lead author Julian Hunt, a Brazil-based researcher with the International Institute for Applied Systems Analysis, said the system is about as cost-effective for generating electricity as wind, solar and regular hydropower.


  1. David Foster says:

    Freight trains powered by electricity from an overhead line — and returning power to the line when going downhill — were a thing in mountainous districts in the 1920s. Not exactly a new, “high tech” idea.

    Concerning the use of water trucks to generate power: if you have water at a high elevation, why not just build a conduit running downhill and run it through a turbine? What do the trucks add, except a perpetual expense stream to replace tires, etc?

  2. Wang Wei Lin says:

    Also known as perpetual motion. The king is not wearing any clothes.

  3. Bruce says:

    “About as cost-effective as (other green energy scams)” sounds accurate.

  4. Jim says:

    >CTRL-f "nuclear": zero results.

    It’s always the same with these hecking people.

  5. James James says:

    The UK’s last aerial ropeway uses no power, moves 300 tonnes

  6. JBP says:

    Hahaha. What a load. The truck generates more energy going down because it weighs twice as much going down. So this scheme only works when loads are going downhill. In open pit mining this would not work at all. BUT, as long as it is not subsidized by taxpayers, go for it.

  7. Bob Sykes says:

    One notes that the shale is LIFTED up out of the mine to the top of the ropeway. It’s a very clever device, designed back when the average UK IQ was about 10 points higher. But the First Law still applies.

  8. Isegoria says:

    The argument for it is not that it’s a perpetual-motion machine:

    To start with, electric truck hydropower can be much less expensive than the alternatives.

    “You just need to buy electric trucks and be able to connect them to the grid — that’s the whole cost,” he said. “But for hydropower plants you need huge dams, tunnels, turbines, and lots of other different components that have very high investment costs.”

    Depending on conditions, the water-carrying electric trucks could also be deployed to generate electricity from different stages of a mountain descent, or even from different rivers on different roads. “It’s very flexible, very modular,” he said.

  9. Gavin Longmuir says:

    “‘You just need to buy electric trucks and be able to connect them to the grid — that’s the whole cost,’ he said.”

    That may be the whole cost of the apple, but that apple is in no way comparable to the orange of the power generated by a hydro-electric installation — not unless the electric trucks can carry as much water in a day as the pipeline to a power plant. That sounds like a lot of heavy trucks, which will require a lot of road improvements & widening & lights for night-time operation. It will also require a lot of water to transport, which (surprise!) will require impounding large volumes of water, which probably means (surprise again!) building a dam.

    The idea may have some modest utility in some very particular circumstances — but it is not a serious large-scale alternative to hydro-electric power.

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