A new company that aims to build and sell planes that run on hydrogen-powered electricity emerged from stealth Wednesday. ZeroAvia, based in Hollister, Calif., claims its planes will be cheaper to manufacture and fly than standard jet fuel-powered vehicles, while also producing none of the carbon emissions that make the aviation industry one of the worst polluters.

ZeroAvia plans to initially target small planes of 10-20 seats that fly short, regional hops of up to 500 miles. The company has conducted a number of successful flight tests using its prototype in a Piper M-class airframe. At a 2-ton takeoff weight and six seats in a business-class arrangement, the prototype is currently the world’s largest zero-emission aircraft flying without any fossil fuel support, according to the company.

The Federal Aviation Administration authorized ZeroAvia to operate its prototype for test flights earlier this year. Since then, the aircraft has completed a variety of test flights, which validated key components and their integration into a complete powertrain system. These tests confirm the company’s “fuel” economy and maximum power delivery targets.

The idea of electric-powered flight has been around for decades, but only recently has it begun to take off. There are over a dozen startups and companies today that are pursuing battery-electric and hybrid prototypes, and some are even suggesting that we could all be nibbling on pretzels and scrolling through in-flight entertainment from within zero-emission, battery-powered aircraft sometime in the next decade.

The question is, what kind of powertrain will spur the airplanes of the future? Most electric cars use lithium-ion batteries, but a few automakers offer hydrogen-powered drivetrains. Hydrogen is the most abundant element in the universe, so its appeal to the fossil fuel-addicted auto and aerospace industries is obvious. Hydrogen fuel cells use compressed hydrogen as their fuel and release only water vapor. The technology has been in development for decades.

But flying requires an incredible amount of energy, and presently, batteries are too heavy and too expensive to achieve liftoff. The technology that allows Tesla to squeeze 300 miles of range out of a Model 3 or Chevy to get 200 miles out of the Bolt isn’t enough to power more than a two-seater aircraft with a flight range limited to only a few miles.

The business of electric flight is extremely difficult, too. Zunum Aero, a startup backed by Boeing and JetBlue, recently laid off dozens of employees and brought its operations to a halt after its coffers ran dry, according to Forbes. Zunum’s business plan was very similar to ZeroAvia: small, nine- to 12-seat planes making short, regional trips.