not so fast

This sports car runs on saltwater—but it’s no threat to Tesla

When a months-old company called NanoFlowcell AG showed up at the Geneva Motor Show in March 2014, debuting its prototype for a “supercar” powered by saltwater-filled flow battery, onlookers appeared intrigued but skeptical.

Yes, the Quant e-Sportlimousine was snazzy, and enough research was being done to suggest that liquid-flow batteries (which combine the technologies in regular batteries and fuel cells) could be the future of electric cars, but there was good reason to question the car’s prospects. NanoFlowcell’s founder, Nunzio La Vecchia, had brought another “Quant” car to Geneva before, in 2009, which never made it past the auto show circuit. And though La Vecchia insisted that NanoFlowcell’s 2014 prototype was completely different, few were convinced that it would ever be seen on actual roads. “It’s possible we can see this type of system utilized in the next few decades,” wrote “So check back with TopSpeed in 20 years or so for any updates.”

But now that the Quant e-Sportlimousine has been approved for use on European roads, there’s more enthusiasm, and some in the tech media are making the inevitable comparison with the high-profile luxury electric carmaker Tesla Motors and its Model S. The concept of the car, after all, is stupendously attractive. It has four motors—one for each wheel—powered by electricity generated from a process of filtering ionic liquid, or saltwater. The car carries the electrolyte fluids in two adjacent 200-liter tanks separated by a membrane. The fluids in each tank are slightly different, and it’s the reaction between them when they cross the membrane that creates electricity.

NanoFlowcell says its car can go for 370 miles on a single charge. Among the other (somewhat outlandish, and as yet unverified) claims: It takes 2.8 seconds to go from 0 to 62 miles per hour (the Tesla Model S takes 4.2 seconds to do the same); has a top speed of 218 mph (almost 100 mph faster than the Tesla S); and peaks at 920 horsepower (compared to 416 for the Tesla S). Until road tests get underway, though, this might as well be fantasy. At least it’s a beautiful one:

General Electric has been working on flow battery technology for years and announced in August 2013 that it aimed to power a car with a water-based battery for 240 miles, though there is no word on whether much progress has been made there. Flow cell batteries have the potential to power cars three times as far and for one-fourth the cost of lithium-ion batteries (the sort that industry darling Tesla Motors is betting big on), according to GE. Flow cell batteries are said to be safer, lighter, and easier to recharge than lithium-ion ones, as well.

It’s a shame, then, that the makers of the Quant e-Sportlimousine had to put their amazing saltwater battery in a car that, should it ever hit the market, may cost about $1.7 million, making Tesla’s Model S luxury electric car look like a bargain at $70,000 to $95,000.

And that’s why Tesla probably has nothing to worry about here: If the only way to get a saltwater-powered battery into a car is to price it like a moderately sized mansion, then lithium-ion batteries just look even better.

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