Solar Impulse: We’ll see solar-powered passenger planes within 10 years

The co-pilots and founders of Solar Impulse – the remarkable solar powered plane that is making a ground-breaking flight around the world – have made a stunning prediction: There will be short-haul electric planes for up to 50 people operating within 10 years.

“This is the beginning of a new cycle,” co-pilot Bertrand Piccard told the Bloomberg New Energy Finance publication Clean Energy and Carbon Brief in an interview this week. He predicted a “new paradigm” of planes flying with no fuel, but being powered by batteries that are charged by solar power.

“Before 10 years’ time, we will have short-haul electric airplanes for 50 people,” Piccard said in the interview.

Piccard and co-pilot Andrew Borschberg have nearly completed the unique, 35,000kms flight around the world, which began early last year. The odyssey – interrupted by battery storage issues after a flight from Japan to Hawaii – will finish when the last leg from Cairo to the original starting point in Abu Dhabi is completed within the next week or two.

The 2.3 tonne Solar Impulse plane is powered by 17,248 solar cells and 4 lithium ion batteries connected to the electric motors that drive the propellors. It uses the batteries to provide the energy to fly through the night, where it slowly loses altitude. The solar panels provide the power to the electric motors and charge the battery during the day, when the plane regains altitude so it can use less power at night.

The people behind the project have always said that they are pushing the limit of the technologies, and it was not really expected that the world’s skies will be full of solar planes anytime soon, although it was thought that their work could lead to more efficient use of clean energy on the ground.

And indeed, Piccard and Borschberg are not predicting that passenger planes could fully refuel with solar power in long haul flights.

They understand only too well the fine lines they have drawn during their single-person long haul flights – some as long as five days – as they wait for the sun to rise and recharge the batteries. Using solar on wings to power a plane loaded with passengers is just not feasible.

But they do see the potential in using electric motors for passenger flights. With 97 per cent efficiency, they say, the electric motors are too good to ignore. And the electric motors and the batteries that accompany them can be charged with solar, along with any other source.

“Solar Impulse has shown what is possible. The industry now needs to take over… it will be interesting to see who does it first,” said Piccard.

The two pilots draw comparisons of their achievements to the Wright brothers in 1903, whose plane also flew slowly with room for only one pilot and in good weather conditions. But it has become the first solar lane to cross the Pacific Ocean, spending 5 consecrative days and nights in the air.

In doing so, they project team has helped develop batteries with a higher energy density and solar cells with a higher efficiency than those found on the market.

Their next project is to work with Solvay and ABB and develop an “unmanned solar-powered aircraft”, which will “run applications” beyond the capacity of today’s satellites. “In three years we will have the first prototypes flying,” Borschberg says.

“When the Wright brothers started to fly in 1903, it was the beginning of the cycle of aviation that put two men on the moon and allowed 500 people to travel intercontinental on the same airplane,” Piccard says.

“Solar Impulse is the beginning of a new cycle. We are in an airplane with one pilot only, in good weather, flying slowly like the Wright brothers but with this new paradigm of having no fuel.

“It will be very interesting to see where these new technologies will lead us. I am sure that before 10 years’ time, we will have short-haul electric airplanes for 50 people.”

Piccard describes the feeling of flying in a solar plane as like a science fiction movie. “It’s ethereal, unreal. The propellers are turning, there is no noise, no fuel, and it is running just from the sun. It’s like being in a fairytale, it’s so addictive.”