Solar Impulse 2, unveiled in April, is the largest electric aircraft with a wingspan of 72 m.

And because its wings are covered with 17,248 photovoltaic cells, which is enough to fly at daytime and accumulate energy for the whole night, it could theoretically stay in the air forever. This is important because the team behind the project would like to fly around the world without landing.

This two-seater weights 2,300 kg (5,070 lbs), from which 633 kg is battery pack weight. We believe that total capacity of the battery pack is well over 100 kWh.

Four motors propel the Solar Impulse 2, each of 17.5 HP or about 13 kW for total 50 kW output, to speed of up to 90 km/h (56 mph).

Solar Impulse 2

Solar Impulse 2

Here are videos from the unveiling:

While the around the world trip is scheduled for 2015, SI2 already has its maiden flight behind it in June:

Solar Impulse 2

Solar Impulse 2

Solar Impulse 2

Solar Impulse 2

Solar Impulse 2

Solar Impulse 2

Solar Impulse 2

Solar Impulse 2

Solar Impulse 2

Solar Impulse 2

Solar Impulse 2

Solar Impulse 2

Solar Impulse 2

Solar Impulse 2