EVO’s Deal with Lotus Highlights the Other Part of the Electric Vehicle Equation
By Amy Westervelt
EVO Electric’s chief technology officer shared an important bit of news with a room full of venture capitalists at the Cleantech Forum in San Francisco: The three-year-old British startup had just formed a key partnership with luxury carmaker Lotus. The Lotus Group officially unveiled the partnership this morning, announcing that its concept Evora plug-in hybrid, on display at the Geneva Auto Show, will include two EVO electric motors and an EVO range extender system.
It’s the first electric vehicle announcement in quite awhile that touches on something other than batteries or plug-in infrastructure, a fact that either hints at a dearth of technology or results in that section of the market, or an excessive secrecy among those working on motor, drive train and range-extender technology.
More than likely, it’s a bit of both, combined with a general lack of understanding of the details that make any given innovation in motor technology interesting. In other words, motors are complicated, but batteries are pretty straightforward.
“Everyone always focuses on batteries in the electric vehicle space, but we like to point out that in order to really create an electric vehicle revolution, you need a small, light, efficient and affordable machine … not just a battery,” EVO Chief Technology Officer Michael Lampérth told SolveClimate at the forum.
The crux of EVO’s technology is an axial flux (or disc-based) motor, which is quite different from the conventional cylindrical motor. Lampérth compares the benefit of an axial flux motor to that of disc brakes versus drum brakes. Axial flux motors are not new technology, but previous attempts to use such a motor in cars have not worked out well because, according to Lampérth, it’s difficult to build machines that can handle the power such motors generate.
On its engineering blog, Tesla engineers have written fairly extensively about changes to its power train made to handle the higher torque and current it produces. The Voltec powertrain being used by Chevrolet for the Volt is a cylinder motor, and its range extender is linked to a gasoline combustion engine rather than an electric generator. Lampérth claims EVO has managed to not only handle the power, but also deliver extremely high performance.
“What we can demonstrate is amazing, but since it’s less than what some companies claim they can do it hasn’t gotten much attention … even though those claims have not yet been backed up by a demonstration,” Lampérth says.
With its products now in the Lotus Evora, EVO has a chance to prove its potential to the world.
In CNET’s review of the EVO-equipped Lotus Evora, Wayne Cunningham notes that the car’s performance bests that of both the Chevy Volt and the Tesla roadster. Each of the car’s rear wheels is powered by an EVO electric motor and according to Lotus, the torque provided by the motors allows the car to go from 0 to 60 mph in just 4 seconds. By way of comparison, the Tesla Roadster matches that, and the Chevy Volt goes from 0 to 60 in 8 to 9 seconds.
The key difference between the Lotus Evora and the Tesla, which is built on a Lotus platform, is that its lower weight makes for reduced battery capacity needs and optimized fuel efficiency. The EVO range-extender, which powers an electric generator, also helps lower manufacturing costs and deliver 47 horsepower, according to Lotus.
“The high power and torque density of EVO’s Axial Flux motors and generators make it easier to package and integrate range extenders into vehicles, and contributes to optimizing fuel economy,” Lampérth says.
Range extenders and power trains — sexy they are not, but they are crucial to delivering on the lower-emissions promise of electric vehicles.