Perpetual motion has been discovered at Pilbara in Western Australia. Good kind of. Fortescue Mining has discovered that its new electric ore-hauling trains will produce more power than it needs.
There is no smoke or mirrors. No laws of physics are broken.
Everything is thanks to gravity.
This is not a new concept – it is in the nature of an electric motor to also be an electric generator. Regenerative braking is a feature of nearly all electric vehicles, although they don’t operate on the same scale as a train.
It’s about the immense weight of an iron ore cargo that has to be mastered on long, gentle slopes. The brakes that keep the 2.8 km, 35,000 tonne load stable regenerate this friction into electricity and power the locomotive batteries.
By the time they have reached their destination, the batteries are full.
It’s an idyllic win-win situation for business profitability and climate change mitigation.
Fortescue Metals Group Chairman Andrew Forest has announced plans to embrace electric trains – and profit from the process.
Fortescue currently operates 16 trains with 54 locomotives which burn some 82 million liters of diesel per year. This represents 11% of the company’s total carbon emissions.
It plans to build a fleet of “Infinity Trains” to harness the energy potential of four of its rail lines from the Pilbara. These have sufficient gradients to their destination of Port Hedland.
Such terrain greatly simplifies the process.
“Regenerating electricity on the downstream loaded sections will eliminate the need to install renewable energy generation and recharging infrastructure, making it a capital efficient solution to eliminating diesel and emissions from our operations. railways,” said Elizabeth Gaines, CEO of Fortescue.
All four Pilbara routes are to be equipped with regenerative trains by 2030. Any excess electricity will be offloaded to support the company’s other regional operations.
“The business opportunities are obvious for FFI [Fortescue Future Industries] as a pioneer of this technology, captures its value and distributes it globally,” says Forest. “Less obvious is that we have the opportunity to not only reduce our operating costs, eliminate the cost of diesel from our business, but of course eliminate carbon emissions from our rail system.”
Read also: Steelmaking is critical – and an extremely serious carbon problem.
Other Australian miners are embracing the idea – although not all routes offer a net energy gain.
Every bit counts. Especially when each train has three locomotives carrying some 250 wagons.
Rio Tinto has announced plans to purchase four battery-electric trains for use in the Pilbara. The power they do not recover through their brakes will be replaced by specially designed charging stations.
The first should be delivered in 2023.
“Battery electric locomotives offer significant near-term emissions reduction potential as we seek to reduce our carbon emissions in the Pilbara by 50% by 2030,” said Richard Cohen, director of Rio Tinto.
The potential of gravity-assisted power generation was the subject of a recent study published by the scientific journal Elsevier Energy.
He proposes to create transport systems bringing water from high altitudes to fill the reservoirs of coastal or lowland cities, “converting the potential energy of water into electricity with the regenerative braking systems of electric trucks and storing it in the truck battery.
The empty truck would not need all that electricity to return to its starting point. Nor does it need to be a specifically designed or dedicated infrastructure.
“The energy stored in the electric truck can be sold to the grid or used by the truck to transport other goods,” the study says.
He estimates that hydropower from electric trucks would cost between US$30 and US$100 per megawatt hour. That, he says, compares to the US$50 to US$200 per megawatt-hour of conventional hydroelectric dams.
“In addition to being a low-cost, impactful power generation technology, electric truck hydropower can work in combination with solar and wind resources and provide energy storage services to the grid,” concludes -he.
Forrest de Fortescue agrees: “Business leaders and politicians everywhere (must realize) that fossil fuels are just one source of energy and there are others now, like gravitational energy, which are rapidly emerging, more efficient, less expensive and green. The world must, and clearly can, emerge from its highly polluting, deadly, even halted fossil fuel era.