Flights of fancy for aviation? Biofuels and solar

In a little over a century powered flight has moved from the miraculous to the everyday. Now, the aviation industry is planning for the next step.

As the 21st century progresses, a new era of aviation seems to be upon us, with flights powered by solar and biofuels no longer seeming like science fiction.

Last year, Solar Impulse 2, the solar-powered aircraft, completed a record breaking non-stop flight from Nagoya in Japan to Hawaii, which lasted over 117 hours.

In May 2014 Dutch airline KLM launched a series of transatlantic flights from Amsterdam to Aruba and Bonaire. During these flights, an Airbus A330-200 was powered by a mixture of fossil fuels and sustainable biofuel.

Jean Revillard | Getty Images

There is still work to be done, however. According to the Air Transport Action Group (ATAG), more than three billion people took to the skies in 2013.

ATAG states that aviation is responsible for 12 percent of CO2 emissions from transport sources, compared to 74 percent from road transport.

Going forward, ATAG has set itself ambitious goals, and is targeting a 50 percent reduction in net aviation carbon emissions by 2050, compared to 2005 levels.

Creating planes that are both fast and environmentally friendly is a key goal for the aviation industry, and the way that planes are being designed is also changing.

"What we're moving towards now in the 21st century are more novel materials being used on wings," Mudassir Lone, from Cranfield's Center for Aeronautics, told CNBC.

The Center for Aeronautics is one of the world's biggest centers for postgraduate education and research into aerodynamics and aircraft design.

"So, consequently the wings can be made far more lightweight. At the same time the actual wing geometry is changing, because we want to minimize drag and hence improve efficiency of the aircraft," Lone added.

The use of carbon composites in aeroplanes is another innovation that could also transform flight.

"Carbon composites is one of the big developments: being able to make very efficient structures, very… lightweight, to imbed systems into the structures themselves," Iain Gray, director of aerospace at Cranfield, said.

For Pericles Pilidis, from Cranfield's Center for Propulsion, the future of aviation could be very green indeed. "Thirty, 40, 50 years from now, my hope is you will all be flying 'pollutionless' aircraft, based on hybrid fuels," he said.

And while the fuel that we put into our planes and the way that we design them is crucial to making air travel sustainable, other factors still need to be addressed.

"We need to pay more attention to airports and ground operations, which are also part of the environmental footprint of aviation," Arpad Horvath, a professor at the department of civil and environmental engineering at the University of California, Berkeley, said.