A regional Australian airline has unveiled plans to retrofit some of its planes with electric-propulsion engines, describing it as the future of air travel.

Rex Airlines has flagged Mount Gambier, in regional South Australia, as one of the initial routes that will trial the electric planes in 2024, which promise to be quieter, less polluting and easier to maintain than the existing jet engines.

It will be the first airline in Australia to trial electric commercial flights. Other smaller aviation companies have said they would be looking to do something similar by the end of the decade.

The airline's deputy chairman John Sharp also expects it could eventually lead to cheap airfares for country passengers.

Mr Sharp said Rex had invested with Dovetail Electric Aviation to develop and certify the retrofitting of electric engines in some of its existing regional planes.

"And we'll put in an electric motor that will be supported by a combination of both batteries and hydrogen.

"Between the batteries and the hydrogen, the electric motor will drive the aeroplane through the air and get you from A to B."

Mr Sharp warned it would not be a quick process.

"It will require all the approvals of the Civil Aviation Safety Authority to ensure it's all safe," he said.

"But I expect that we'll be seeing this happening in this decade, which is something I would not have thought possible three years ago."

The technology has been previously used in smaller aircraft, such as two-seater planes.

"This is sort of leading the world if you like, in this type of technology," Mr Sharp said.

"We've been looking around for a company that had technology we thought could work for us, and this company seems to, so we're going to give it a try."

Reducing carbon emissions

While also being cheaper to operate, the retrofitted aircraft are expected to be safer and quieter for people living near airports.

"It's dramatically different. The electric motors are inherently safe — they're probably safer than any other form of motor," Mr Sharp said.

"The other good thing is that it will produce far less carbon emissions — basically, none.

"That will help contribute towards our national objective of reducing carbon emissions over the next few years."

For regional passengers, the technology brings the possibility of cheaper travel due to the reduced costs of running an airline.

"It's got three benefits — one being the potential for lower airfares," Mr Sharp said.

"But secondly, it means that routes that are marginal routes that we operate now that really — you wonder whether you should bother to continue to do them — it'll make those routes viable for the long-term.

"And it will open up new opportunities in the towns and cities where you would not have thought it would be viable to operate a regional air service.

Rex aims to initially trial the technology on its 34-seat aircraft used on regional routes under one hour, such as its Mount Gambier to Adelaide service.