The Swiss duo didn’t stop here. They toiled hard with their team of engineers and other professionals to improve the design and working of the solar aircraft. Solar Impulse 2 was the sequel to the original Solar Impulse project and was destined to reach even greater heights. The Solar Impulse 2 aircraft, which took to the skies in 2015, covered a massive 43,000 kilometers at an average speed of 75 km/hour—all without using a single drop of conventional jet fuel.
In 2015, when Solar Impulse 2 soared through the air with a wingspan wider than a Boeing 747, it became the first solar airplane to complete an oceanic crossing, flying from Japan to Hawaii using nothing but solar power!
Now, let’s look a bit more closely at the solar-powered aircraft’s design and construction.
Also Read: Why All Airplane Windows Round Not Square Or Rectangle ?
Construction of the Solar Impulse 2 aircraft
Just like domestic solar roof panels, the Solar Impulse 2 aircraft uses devices called photovoltaic cells or solar cells to generate electricity from sunlight. These cells are made of silicon and are very thin. Silicon is a semiconductor that conducts electricity in certain conditions, while acting as an insulator in certain other conditions.
Now, when photons of sunlight hit a solar cell, it compels the electrons to move from one side of the silicon wafer to the other. This “flow of electrons” is what we popularly call ‘electricity’. Solar Impulse 2 has 17,000+ solar cells installed on its surface. The electricity these produce powers the aircraft’s motors, which turns the propellers and charges the onboard batteries. These batteries preserve the power required by the aircraft to fly at night. The aircraft uses 633 Kg of lithium polymer batteries, which account for roughly 25% of the aircraft’s weight.
In terms of motors, this aircraft has four electric motors, each delivering 17.5 horsepower. The Solar Impulse 2 aircraft uses clever composites, such as carbon fiber, in the plane’s airframe to ensure that it is lightweight. Making the plane lighter means that less energy is required to keep the aircraft flying.