Nokia announced the end of a research program into solar powered mobile phones concluding that integrated solar panels were "possible but challenging."
The prototype phones, which have a large solar panel on the rear, were produced as part of research with the aim of "possibilities for phone charging in conditions where it’s not possible to plug in to recharge the phone, or where the electricity supply is uncertain," Nokia said.
A surprising variety of test location was used including Kenya, Southern Sweden, a team sailing in the Baltic Sea and another at the Arctic Circle.
"When carefully positioned, the prototype phones were able, at best, to harvest enough energy to keep the phone on standby mode but with a very restricted amount of talk time," Nokia concluded.
Unsurprisingly they said that a large part of the challenge was the limited size of the back panel and hence the solar panel. The testing in Kenya went well as you might expect with the extreme northern depending on the time of year.
"This means there’s still some way to go before a workable and care-free solution is achieved," Nokia said.