Bertrand Piccard, the first man to travel around the world in a hot-air balloon, plans to circumnavigate the globe in 2015 in his plane, Solar Impulse, which has 12,000 solar cells on its wings. Unlike other solar-powered planes, the Solar Impulse has energy-efficient batteries that allows the vehicle to fly even at night. "These cells capture the energy of the sun and transform it into electricity. This electricity goes simultaneously to the engine and to the batteries. Then we reach the next sunrise, and we capture the sun again, and we can continue, theoretically forever," Piccard said.