Published on May 7th, 2015 | by Steve Hanley
New Wrightspeed Micro-turbine Range Extender Introduced
The new Wrightspeed micro-turbine range extender is 30% more efficient than any existing turbine powered generator. Wrightspeed is a start-up created by Ian Wright, one of the co-founders of Tesla Motors. He disagreed with the way Elon Musk was running the company, so he cashed in his stock and walked away. That decision cost him millions. That’s just crazy, right?
Crazy like a fox, maybe. He founded his own company called Wrightspeed to produce electric powertrains for heavy duty vehicles — like garbage trucks. Wright says his each of his trucks can save fleet operators as much as half a million dollars over its useful life, thanks to lower fuel and maintenance costs.
The Wrightspeed micro-turbing range extender generator is a cutting edge new design. Named Fulcrum, the 80 kW unit uses a two stage compression process and a novel recuperation design that makes it 30% more efficient while tripling usable power according to Green Car Congress. The turbine can run on diesel, CNG, LNG, landfill gases, biodiesel, kerosene, propane, heating oil, or any other combustible fuel.
Turbine technology has been tried in automotive applications before, but the results were always disappointing. Turbines are not well suited to the changes in operating speed required by stop and go driving. The key to the Fulcrum micro-turbine is that it operates only at its most efficient speed of around 100,000 rpm. To increase efficiency, the Fulcrum recovers a portion of the exhaust heat by using a heat exchanger called a recuperator to increase the energy of the gases entering the expansion turbine. “Without a recuperator,” says Wright, “efficiency is just horrible.”
The Fulcrum micro-turbine generator weighs far less than a traditional piston engine powered generator. It’s exhaust is so clean, it requires no catalytic converter to meet California’s stringent emissions standards. Weighing just 250 lbs, the Fulcrum has a remarkably high power to weight ratio of 750 kW per kilogram. It has also been designed to be affordable by minimizing manufacturing costs.
Wrightspeed emphasizes the use of high-power batteries rather than high-energy batteries in its powertrain. Says Wright:
One of the things that enables the story is that the batteries have become extremely reliable and long life, even when at high power. We use the smallest pack we can. In general, we save fuel in three separate ways: first is with a grid charge; second is regenerative braking—we run very high power regen, much, much higher than anyone and we pretty much avoid the use of friction brakes; and third is running the engine at the sweet spot.
Elon Musk’s quest is to build high performance cars for the fortunate few. Ian Wright’s mission is to make the vehicles that pick up our trash and deliver our packages as efficiently as possible in order to dramatically reduce the amount of carbon dioxide they add to the atmosphere each year. Musk gets all the headlines, but which man is making the more important contribution to the environment?