LiquidPiston built a functioning engine and has demonstrated it powering a Go-kart. Shkolnik says the engine could see its first practical application, in a drone, within a few years. The liquid piston engine weighed 4 pounds and replaced a 40 pound engine.
Ultimately, the LiquiPiston engine will power exoskeletons, robots, drones, boats, electric cars, and generators. A typical 30 kilowatt-hour generator weighs 1,000 pounds or more, with military versions are closer to 3,000 pounds. Shkolnik says LiquidPiston’s engine could generate that kind of power in a unit that weighs less than 400.
Shkolnik says LiquidPiston can make its gas-powered engine so efficient, it could recharge the car with fewer emissions than plugging into the grid, at least in areas that burn coal for power. Developing the engine to that stage will take partnerships, and the company is in discussions to license its tech.
The engine is an all-metal rotary engine. It is an inside out Wankel engine.
The go-kart’s conventional piston engine is on the left, the LiquidPiston rotary alternative is on the right
IEEE Spectrum interviewed Shkolnik
“Many people immediately try to sell improved engines to the automotive and truck market, and I can’t blame them, it’s a $300 billion market,” Shkolnik says. “But to bring a new engine to life in the automotive world takes at least seven years and costs, quite literally, $500 million—and that’s for a piston engine, where the risk is low.”
So he’s looking first at markets that have an urgent need for very compact engines—hand-held power tools, cargo-carrying drones for the likes of Amazon and FedEx, and most interestingly, range extenders for cars.
“We have the concept of a 30-kilowatt engine operating on diesel, 30 lbs, in a 10 by 8 inch box,” Shkolnik says. “It could be part of an e-vehicle for masses, giving you the range you’re accustomed to—300 miles instead of 30—and rapid refueling.”
Nextbigfuture has covered LiquidPiston several times in regards to the DARPA funding for an small engine for powering exoskeletons
SOURCES – IEEE Spectrum, Wired, DARPA, LiquidPiston