Eco-friendlier hydroelectric tech would swap dams for electric trucks

Eco-friendlier hydroelectric tech would swap dams for electric trucks
The Electric Truck Hydropower system would take advantage of existing steep mountain roads running alongside rivers
The Electric Truck Hydropower system would take advantage of existing steep mountain roads running alongside rivers
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A diagram of the Electric Truck Hydropower system
A diagram of the Electric Truck Hydropower system
The Electric Truck Hydropower system would take advantage of existing steep mountain roads running alongside rivers
The Electric Truck Hydropower system would take advantage of existing steep mountain roads running alongside rivers

While hydroelectric dams are capable of generating a lot of electricity, they drastically disrupt the environment. Scientists have now proposed a simpler but still effective alternative, in which electric trucks replace such dams.

In a typical hydroelectric facility, a dam is built across a river, causing a reservoir to form directly upstream of that dam. When a gate in the dam is opened, water from the reservoir flows through and drops down to a lower elevation. As it does so, it spins up turbines which generate electricity.

Unfortunately, formation of the reservoir involves the flooding of land which may previously have contained forests, crops, or even people's homes.

The presence of the dam can also significantly slow the flow of the river, raise the water temperature, and cause sediment to accumulate within the water. Additionally, dams often block the upstream migration of spawning fish, plus fish may be harmed when travelling downstream through the gates.

That's where the Electric Truck Hydropower system is intended to come in. The concept, which could be put to use in mountainous regions with steep roads, is being developed by scientists from the International Institute for Applied Systems Analysis.

Initially, at a "charging site" located at a high elevation on a mountain river, large tanks would be filled with water from the river. Each tank would be loaded onto a separate electric truck, which would then carry the tank down the mountain. Due to the steepness of the road, the driver would essentially just be riding the brakes all the way down, with the water greatly adding to the vehicle's inertial mass. Thanks to a regenerative braking system, the trip down would generate electricity which would in turn be used to charge the truck's battery.

Upon reaching a "discharge site" at the bottom, the tank would be removed from the truck, the water contained within it would be released back into the river, and the truck's battery would be removed so it could provide electricity to the municipal grid. The truck would then be loaded up with an empty tank, along with a replacement battery with just enough of a charge to get the vehicle back up to the charging site.

A diagram of the Electric Truck Hydropower system
A diagram of the Electric Truck Hydropower system

The idea is that a fleet of the trucks would be continuously travelling between the two sites, picking up and dumping out water. Importantly, the amount of electricity they consumed on the way up would be considerably less than the amount that they'd generate on the way down.

In fact, the scientists estimate that if the system were implemented on a global scale, it could generate 1.2 petawatt-hours of energy annually. That figure constitutes about 4 percent of world energy consumption for 2019. The estimated cost of the system is US$30 to $100 per megawatt-hour – the researchers state that by contrast, the cost of conventional hydropower ranges from $50 to $200 per megawatt-hour.

"This technology does not require dams, reservoirs, or tunnels, and it does not disrupt the natural flow of the river and fish passage," said the lead scientist, Julian Hunt. "The system requires only roads, which already exist, charging and discharging stations similar to small car parks, a battery facility connected to the grid, and the trucks."

More details on how the Electric Truck Hydropower system would work can be found in an open-access paper, which was recently published in the journal Energy.

Source: International Institute for Applied Systems Analysis

A funicular electric railroad would cost much less to build and operate for generating hydropower than a road plus trucks. Switzerland would be a natural test location. It would likely be more efficient, too.
@EH Or at that point, a pipe from the top of a river to the bottom, with a generator at the bottom.

I get the idea of using existing infrastructure, but that seems awfully convoluted... and maybe not even environmentally friendly, considering the cost of the batteries and trucks.
using potential energy is what we talk about, so hight and mass (and efficiency of the system etc.) is key. obviously in a truck only little amount of water can "generate" energy. this small amount would be measured with a small reservoir/dam. So what is the point???
Spud Murphy
This was already suggested using huge trains, it wasn't viable for trains (see https://aresnorthamerica.com/ who now seem to be very, very quiet), it certainly won't be viable for trucks. This is what happens when academics with no real world experience come up with ideas.
James Barbour
How did they get the water to the top of the mountain? Electric pumps? Where did they get the electricity? From burning natural gas? Hydro power is one acre foot per kilowatt. assuming 2,000 elevation and a 2,500 cubic foot capacity, 20% charge discharge losses and 30 minute round trip…I calculate $3 of net electricity per hour. The lip batteries would depleted in a year resulting in a net loss after replacement. The solution is simple. An aqueduct that runs along the river bed.
I'm with Spud on this one. The on-going cost of maintaining a fleet of trucks is going to eat any gains you hoped to see. Tires wear out, even regenerative braking will wear out, the roads wear out. What about the cost of drivers? What about accidents? It really seems like a worse idea than the train on a fixed rail idea, less friction and no drivers needed. This is a nutty idea.
At the top, there's some sort of mechanism for loading water into the trucks. Hmm, you could replace the road+trucks with a pipe and a turbine at the bottom...

Such silliness.
A small weir across the river at the top, with a pipe (easily camouflaged) connecting to a turbine at the bottom is far less costly to construct and maintain than a fleet of trucks, apart from the environmental impact. If you still prefer something mechanical, a (free wheeling) water carrying 'ski-lift' with generators fitted to the return (or even intermediate) wheels/pulleys would be better than trucks.
Lamar Havard
Just build water wheels instead of 'charge sites' along the river, they've been working well for centuries. @ James, they pump the water into the trucks from the river...at the top of the hill.
It would be interesting to compare the number of trucks that would be required to carry the equivalent amount of water that a simple pipe could to generate equal amounts of energy. If a dam is not required to form a reservoir to fill the trucks from them the same could be said about the supply at the head end of the pipe.
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