NASA has just given out the largest ever prize in aviation history, to the inventors of a super-efficient electric plane.

The CAFE Green Flight Challenge was started to try to develop environmentally-friendly planes that either run on electric power or are incredibly fuel efficient.

The top prize of £880,000 was awarded to the Pipistrel-USA.com team. Their electric plane managed to fly 322km (200 miles) in less than two hours, with a cruising speed of at least 161km/h (100mph).

The entrants had to achieve a fuel efficiency of 200 pmpg (passenger miles per gallon). This is a way to compare how efficient planes are combined with how many passengers they can carry. The average among US airlines is around 64pmpg.

“Two years ago the thought of flying 200 miles at 100 mph in an electric aircraft was pure science fiction,” said Jack W Langelaan, team leader of Team Pipistrel-USA.com. “Now, we are all looking forward to the future of electric aviation.”

Watch the short video below to see some of the planes in flight and to hear some of the inventors talk about the challenge!