Thursday, June 9, 2016

Tesla Co-Founder Targets Trucks For Electrification

From Forbes, June 7:

Mack To Demo Garbage Truck With Wrightspeed Turbine Plug-In Hybrid Powertrain
Humans generate a lot of trash. Refuse trucks circulate through our cities and neighborhoods collecting that trash, typically starting and stopping every few yards. For trucks that can weigh up to 33 tons, all of the slowing down and speeding up uses a lot of fuel and generates a lot of emissions. At this week’s WasteExpo in Las Vegas, Mack Trucks and Wrightspeed are teaming up to demonstrate a plug-in hybrid trash hauler claimed to be able reduce fuel consumption by up to 70%. 

The Wrightspeed Route 1000 powertrain is the brainchild of Ian Wright, one of the co-founders of Tesla Motors. While Wright believes in electrification, he is of the opinion that efficiency efforts would actually have the biggest impact if applied to the biggest consumers of energy such as medium and heavy duty trucks and buses. These vehicles are typically powered by big diesel engines that make a lot of noise and pollution while getting anywhere from 3 to 6 mpg and accumulating as much as 100,000 miles per year. 
Cutaway of a truck equipped with the Wrightspeed turbine plug-in hybrid powertrain (image source: Wrightspeed)
Cutaway of a truck equipped with the Wrightspeed turbine plug-in hybrid powertrain (image source: Wrightspeed)
When Wright decided to tackle this problem, he did it from first principles. Whether you’re looking at package delivery, transit buses, or refuse collection, all of these applications share a need for substantial payload capability. Given the mass and bulk of even the most advanced batteries available today, going all electric was not viable because the batteries would use up too much of the payload, making the vehicles useless. 

Wright’s approach is to size the batteries for about 30 miles of electric driving and then use a range extender to keep the truck going for the rest of the route. Unlike something like the Chevrolet Volt which uses a conventional gasoline four-cylinder engine, Wright found the most efficient type of range-extender available, a small gas turbine. This is paired with a motor/gearbox unit mounted at the drive axles to provide propulsion and regenerative braking from all the stops these vehicles typically do.
 Wrightspeed has been testing its system for several years now with a variety of companies including FedEx and plans to enter regular production by early autumn of 2016. Earlier this year, Wrightspeed announced a deal to supply powertrains to NZ Bus in New Zealand....MORE