Solar Impulse, a big leap

The success of Solar Impulse 2 last week in its circumnavigation of the globe was both symbolic and substantial. It was a demonstration flight to prove that aircraft can fly long distances using solar energy, and it has opened up new possibilities in the use of renewable energy not only in aviation but in many other fields. The prototype aircraft returned to Abu Dhabi, from where it had set off on March 9, 2015, after an epic 16-month flight across four continents and four oceans, covering a distance of 40,000 km. It was originally exp-ected to be a five-month flight. The delay was caused by the many technical and other difficulties it had to face in its course, like the damage to its over 17,000 solar cells during the flight from Japan to Hawaii. But the completion of the flight proved that the challenges and difficulties could be overcome with skill and perseverance.
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.