After a triumphant trans-Pacific flight, the team behind the pioneering Solar Impulse 2 solar-powered aircraft were dealt a major blow when it was revealed the plane’s batteries had been irreparably damaged, forcing its round-the-globe journey to be suspended.
Solar Impulse 2 is on a quest to circumnavigate the world without using a drop of fuel, but it was announced today the plane will stay grounded in Hawaii until April 2016 instead of continuing to the US and then across the Atlantic as originally planned.
“We overheated the batteries during the first day of the [trans-Pacific] flight,” said Bertrand Piccard, one of Solar Impulse’s creators and pilots. “We damaged the batteries. It was an error in the evaluation of how to use these batteries during the steep climb and over-insulation of the battery pack. Now it takes more time to repair the batteries than the time left before the end of the season.”
Engineers discovered the damage to the plane’s lithium-ion batteries after the record-breaking five days and nights of non-stop flying between Japan’s Nagoya in and the main Hawaiian island of Oahu in early July. But despite their hard work, the team concluded the damage was too extensive to allow the plane to continue.
The plane will instead stay in Hawaii in a hangar at the Kaleoloa airport, owned by the Department of Transportation, where repairs will be completed with the help of the University of Hawaii, and continue the journey next year.
In addition to repairing the battery cells, the engineers will attempt to devise better options to address cooling and heating during very long flights.
“Since we left Abu Dhabi in early March, we had so many obstacles that we had to overcome, so many hurdles,” said Andre Borschberg, who piloted the craft during the record-breaking flight. “We learned a lot but it was really difficult, maybe even more difficult than we expected. But I guess what’s really important is that we could do the most difficult leg – flying five days and five nights over the ocean.”
The batteries overheated already during the first ascent to 8,500m. This manoeuvre needs to be performed daily to provide optimal conditions for the plane’s 17,000 solar cells to charge the batteries.
The Solar Impulse project aims to prove that it is feasible for aviation to become completely sustainable.
The plane, about the size of a personal car but with a wingspan of 72m, completed eight of 13 legs of a round-the-globe trip that started in Abu Dhabi in March this year.
In April next year, the plane will continue to US West Coast from where it will fly to New York and then cross the Atlantic for Europe before returning to Abu Dhabi.