(I've written the "Business Europe" column for today's Wall Street Journal Europe. The article is on the WSJ website and below. I've added the first picture to this post).
In a big hangar at a former military airfield near Zurich in mid-May, Bertrand Piccard stepped into a prototype airplane cockpit (picture) and began "flying." And kept on going. For 25 hours straight.
The test, followed a day later by another 25-hour dry run with pilot André Borschberg, went well. It was the first real-scale flight simulation for Solar Impulse, an unconventional aircraft designed to circumnavigate the Earth powered uniquely by solar energy, without producing any polluting emissions. Mr. Piccard's team is planning the first real takeoffs in mid-2009, and then a few months later a 36-hour trip aimed at assessing the feasibility of manned nighttime flights – when the energy source, the sun, is "off."
If everything goes according to plan, a five-leg, monthlong tour of the world will follow at some point in 2011 or 2012, with Messrs. Piccard and Borschberg each flying alternating stretches of five days and five nights between landings. "We're not in it just for the adventure," Mr. Piccard told me. The team wants to use this attention-grabbing challenge to inflect energy and climate policies and "to become a testing ground for the development and exploitation of renewable energies and clean technologies" – with an eye also to their future commercial potential.
Crazy? Sun-powered prototype planes have been around for a while. But this would be the first with a man on board; the first to stay aloft day and night; and the first to take off with its own power, after sitting on the runway until the sunrays, and only the sunrays, have charged up its batteries.
In a world dependent upon fossil fuels, the Solar Impulse project is certainly a provocation. But it comes with credentials. It's the brainchild of Mr. Piccard, a 50-year-old Swiss aeronaut and scientist. His legendary grandfather Auguste in 1931 became the first man to reach the stratosphere in a balloon. In 1960 his father, Jacques, together with U.S. Navy Lt. Don Walsh, was the first to reach the deepest trenches of the oceans, the Mariana's, in a bathyscaphe.
Unable to beat them up or down, Bertrand went horizontal. In 1999, alongside Brian Jones of Britain, he completed the first nonstop, round-the-world flight in a hot-air balloon. The duo prevailed over a number of competitors, including Richard Branson.
Mr. Piccard and his team have already lined up €40 million ($63 million) in sponsorship money from Deutsche Bank, Belgian chemical group Solvay, and Swiss watchmaker (and NASA supplier) Omega. The project also has technological and scientific cooperations with French high-tech firms Dassault and Altran, the European Space Agency, and the Swiss Institute of Technology, among others. The project has even received the official patronage of the European Commission, which sees in it "an example of what industry and energy policy makers should be doing to foster energy efficiency and clean mobility."
The first Solar Impulse aircraft, dubbed HB-SIA, is currently under development (picture left: a virtual rendering of what the plane will look like). It will have the weight of a car (a bit less than 2 tons) but the wingspan of an Airbus 320 (about 60 meters; a subsequent version will be 20 meters wider). The wings will be covered with solar cells. Stacks of batteries will store the energy accumulated during daylight to power the four engines at night.
After sunset, the plane will also glide to preserve energy, gradually dropping to 2,000 meters altitude from the cruising level of 8,500, before climbing again. In this scheme, altitude will become a virtual form of energy: The higher they fly during daytime, the longer they will be able to glide during the night. Dawn will be a critical moment: Have they stored enough energy from the day before, and have they been able to glide long enough so that the plane can "encounter" the sun and start recharging the batteries?
The project presents a variety of extreme design and technology challenges, and it may still fly into turbulence. To succeed, Mr. Piccard's team will have to produce or benefit from others' advances in materials and composite structures, which need to be solid and lightweight. They'll also need ultraefficient solar energy capture (cells) and storage (batteries) that don't exist today, along with more-developed aerodynamics and propulsion. "The key is really energy efficiency," explains Mr. Borschberg. "We need to find ways to extract maximal power from minimal energy, and to fly using as little of it as possible."
They will also have to push the boundaries in meteorology, routing and human physiology monitoring. The pilot will be up there alone for days and nights in a row, wearing a special shirt filled with sensors and even a vibrating system that can be remotely activated to wake him up. He will also have to manage his sleep, food intake and other physical needs in a cockpit built to be narrow and spartan, to help keep the airplane light.
Could this technology one day be used on all airplanes? Even Bertrand Piccard doesn't envision solar planes replacing today's aircraft anytime soon. But the Solar Impulse project aims to become a catalyst for the development of solar and other technologies that could lead to future applications in air travel and in areas other than aviation.
A visit to another, sealed-off part of the hangar reveals a skunkworks where cockpit and wings are being assembled, aerodynamics tested, engines miniaturized, software developed, special ultralight and resistant foams shaped into craft parts. Here lies part of the sponsor's interest in supporting the project: The Solvay engineers, for instance, are working on the foams, intended to protect batteries and engines from big temperature differences – and promise significant future commercial applications, should Solar Impulse succeed.
"We want to show people that renewable energy is not a step backwards but a jump into the future," Mr. Piccard told me. "If we can go around the world in a solar aircraft, that means that we can do incredible things with renewables."