Green Daily

Rolls-Royce has tested a new engine based on an old design. The open-rotor propeller plane, usually seen in old movies, could reduce greenhouse gas emissions by 30% and save a heap of money on fuel.

Modern propeller engine technology is, surprisingly, more fuel efficient than the regular turbojet engines we're used to seeing. A return to open propeller design never caught on, however, partly because of the huge noise these engines made. With fuel prices and environmental concern rising, engine builders like Rolls-Royce are revisiting and trying to improve the technology.

Rolls-Royce has said that recent tests on a propeller design has the engine working quieter than any other operating aircraft today.

At present, CO2 from airplanes are only at 2-3% of the total global emissions. Not a huge amount, but airline travel is growing by a quick 6-7% a year and efficiency is only improving 1% a year. Until solar powered planes get popular, efficiency improvements this like will become more and more necessary. And Rolls-Royce is not the only company looking into propellers -- GE, Pratt & Whitney and Snecma are all creating open-rotor prototypes.