The aircraft, designed by a Swiss team of experts and engineers and flown by two pilots who alternated at the controls, is a contraption with the wingspan of a Boeing and the weight of a car. Its speed did not exceed that of a car. There were stoppages at many places including Ahmedabad and Varanasi. There have been attempts to use solar energy in drones but their functionality has been limited. The important point the Solar Impulse 2 proved is that it could fly with the energy it drew from the sun and preserve it for a long time for flights at night also and in different weather conditions. There are efforts to develop planes which use electrical energy with rechargeable batteries and other unconventional fuels. But the potential of solar energy is the greatest as the source is free and unlimited and it might come cheaper and without the polluting effects of fossil fuels. At present, about 3% of global carbon emissions are caused by the aviation industry and so the benefits of the use of solar power are obvious.
Solar Impulse 2 will have to go a long way to realise the potential it has pointed to. There are major scientific and engineering challenges like improving the design, increasing the weight and developing more efficient solar cells. But it is expected that technology will follow, now that the principle has been proved. That is why the solar plane’s round-the-world trip is considered as a historic event. The spirit of adventure of the two pilots also bear comparison with that of the early pioneers of air and sea travel who changed history.