THE all-electric Tesla S car has wowed all who’ve driven it, and now the Kiwi co-founder of Tesla is working on a parallel feat by reinventing the truck powertrain.
Ian Wright’s 'Wrightspeed' all-electric powertrains won’t revolutionise long-haul transport - that’s still a job for fossil fuels, Mr Wright said, or better, diesel-electric trains - but they are already transforming the operating costs of metropolitan haulage.
“Here in the United States, the average Class 8 full-sized garbage truck is burning $55-$65,000 a year in fuel, and up to $30,000 in maintenance,” Mr Wright told Fairfax from his California headquarters.
“Of that, we can save about $35,000 in fuel and $20,000 in maintenance. They are pretty substantial savings.”
An electrical engineer who worked in Australia before moving to California, Mr Wright co-founded Tesla with Martin Eberhard.
Since leaving Tesla, Mr Wright has taken a fundamentally different approach to electric vehicle power. He has focused on a different area to disrupt, the transport business, and rather than the hassle of building vehicles from scratch, has opted to focus only on powertrains.
A US$200,000 Wrightspeed powertrain retrofit is actually several modules working in tight software-controlled symphony.
In a truck, Mr Wright said, it’s impossible to carry the power you need to do a day’s work.
Wrightspeed retrofits put a power unit on each drive wheel, which drive through a gear reduction unit to maximise torque.
On a big garbage truck, each drive unit is rated at 250 horsepower. On trucks with four drive wheels, the system has to be capable of generating enough electricity to produce 1000hp.
Try and do that solely with batteries, Mr Wright said, “you end up with a very heavy, very expensive powertrain”.
A typical Wrightspeed-equipped garbage truck will get 30 miles (50 kilometres) out of an overnight plug-in recharge of its batteries. “Those are the cheapest miles, because electricity is very cheap compared to fuel,” Mr Wright said.
The second way an electric truck can get energy is by capturing energy normally burnt off in braking. A garbage truck, which can do 1000 hard stops in a day, is the perfect platform for this sort of energy recycling (as are taxis).
The third way is by burning fuel - but rather than burn fuel to drive wheels, the Wrightspeed generator-engine produces electricity.
Even here, the Wrightspeed unit emphasises thriftiness by only firing up the generator - the “range extender” - when necessary, and having it software-controlled to operate only at the speed and load that offers peak efficiency.
The range extender can be run on gas or liquid fuel. At the moment, the customer has to choose an option when the unit is fitted, but Mr Wright hopes the units will later be able to switch between whatever fuel is handy and cheap.
For garbage truck operators, the gas-fired option means the possibility of running the range extender on landfill gas, closing another energy loop.
Mr Wright has also invented a new manual gearbox, part of the Wrightspeed powertrain, that uses software to change gears so fast, a clutch isn’t necessary to slow the spinning gears down for syncing.
At the moment, Wrightspeed can’t turn out powertrains fast enough to meet demand. FedEx is using the units in a couple of its delivery trucks, and one Californian garbage truck operator is getting all eight of his Class 8 trucks fitted with the units.
So far, Mr Wright said, he hasn’t even looked at selling units in Australia, but he presumes that the market for his technology lies everywhere that trucks are being used in a metropolitan setting.
Sadly for the economics of road transport - and luckily for lovers of the exhaust brake - Mr Wright can’t see electric powertrains ever powering long-haul trucks.
However, interest in the technology is throwing up new applications for the powertrains that he’d never thought of - like the tractor-trailer units shifting freight around in long-haul depots.
Although Mr Wright can’t see that electricity will replace fossil fuels in applications like long-haul transport and long-range flight, he is bullish about the future of electric power in general.
It all comes down to battery technology, and on that front Mr Wright has seen enormous change in a short time.
Not long ago, a 270-kilogram pack of lead acid batteries could produce 150 horsepower, power a vehicle for 24km and last about 300 cycles.
A current lithium-ion battery pack of the same weight can be used to generate 500hp, drive a vehicle at least 160km, and last for 5-10 years.
For more information go to the Wrightspeed website.