Table 1 - Specifications of the Solar Impulse 2
Capacity
Wingspan
Weight
Number of solar cells
Number of propellers and batteries
Total energy produced from
Abu Dhabi to Hawaii
Maximum flight time achieved
Maximum altitude
Average airspeed
Maximum recorded ground speed
Fuel consumption
1 pilot
72 m
2.3 tons
17,248
4
5644 kWh
117 hours 52 minutes
28,000 feet
75 km/h
216 km/h
0 litre
Table 2 - How does the Solar Impulse fly by day as well as by night?
6am: The sun has just risen. The airplane is on the runway. Its batteries, charged by the sun on the
previous day, are nearly full. So it can take off using that stored energy...
6am-6pm: It gains altitude. The four motors turn at maximum power as the plane must create lift (the
force that allows the plane to climb) to reach a thinner layer of air where there are fewer clouds. Despite
the steady energy consumption, the batteries are charging.
Nearing 6pm: It reaches 9,000m, its maximum altitude. The sun’s rays fade. The motors are throttled
down and the plane starts to glide down to an altitude of 1,500m, which takes about four hours, during
which time it consumes almost no electricity...
Nearing 10 pm: At 1,500 m of altitude, the pilot powers up the motors again, but this time they will
take their energy from the batteries. The airplane flies like this until daybreak when solar energy again
feeds power to the motors and recharges the batteries. A new cycle begins.
Making of Solar Impulse : Solar panels (R) and propeller (L)
29