The Solar Impulse is currently the most advanced plane in existence that runs entirely on solar power. In 2010 the Solar Impulse made headlines when it completed the first ever solar powered night flight, flying 26 hours non-stop. In 2012 it flew from Europe to Africa which was the first intercontinental solar powered flight. In 2015 the founders are planning to make the first solar powered coast to coast flight which will start in San Francisco and end in New York.
The plane has a massive wingspan of over 208 feet, weighs less than a car, and has a cockpit just big enough for the pilot with no passengers. Most of the wing area is covered in photovoltaic cells (solar panels) that power the plane in daylight while also sending power to be stored in the plane’s battery which is what allows the plane to fly at night. One of the things that amazes me about the Solar Impulse it that the solar panels only generate enough power to give the plane about 8 HP. This is about the amount of power the Wright brothers were working with when they made their first powered flight! It is practically nothing and as a result the plane has a top speed of just 43 mph with a maximum bank angle of 10 degrees. It is also vulnerable to bad weather and it cannot fly through clouds so, overall it is quite fragile. The creators of the Solar Impulse have stated that the technology employed in their plane would not come close to replacing jet fuel powered commercial airplanes. To power a commercial airliner it would take two solar panels roughly the size of football fields which would obviously not be feasible at all.
It is clear that this plane is more of a demonstration of the potential of solar power in the future and also the movement towards using environmentally conscious forms of energy as much as possible. So while this may not be a very practical design for today’s airplanes, it is still very much a feat of remarkable engineering and it gives me the feeling that I am getting a glimpse into the future of one area of the aerospace industry. The creators of the Solar Impulse are already working on the next generation solar powered plane which will supposedly be able to complete the first solar powered flight around the world. After that, who knows where this technology will take us. I imagine that someday we might be able to use solar power to travel to outer space.