Silicon Valley company Alta Devices have created prototype cases that will enable mobile devices like cellphones and tablets to use solar energy to increase their battery life by up to 80 per cent.

“We are already producing chargers of various kinds, but not yet for retail sale,” said Dr Brendan Kayes, a senior engineer and engineering scientist at Alta Devices. He hopes the technology will be available to consumers as soon as 2015.

The difference between Alta Devices’ prototypes and what is currently available on the consumer market is that Alta Devices cells are so efficient and lightweight they will even work under artificial light.

The company’s breakthrough is finding a way to create cells that are lightweight, flexible and efficient – characteristics that do not usually correspond.

Although devices would still require a battery to be charged from a wall outlet, their batteries could also be charged by leaving them in light.

“Our technology provides several times the power per unit area of the best flexible solar options currently available for consumer devices,” Dr Kayes said. “We can fit four to five of our cells on the back of a cellphone. That means roughly one watt of charge under direct sun. Every minute the phone is in the sun you get a minute of talking time,” he said.

The development of a thin, two-layered film of gallium arsenide – a compound used on satellites due to its high efficiency – and indium gallium phosphide, are the key leading to their use in mobile technology.

The double layer allows the absorption of more light energy, resulting in a more efficient, lightweight and durable product.

The company has already built prototype solar cases for iPhones and the Samsung Galaxy S3, and the technology could easily be applied to other smartphones.

The repercussions of this technology could go well beyond charging a dead phone. The US Army is currently using the company’s cells to take the strain off generators and there is even the possibility of using them to increase fuel economy in cars, unmanned aircraft and their integration into backpacks, tents and clothing.

Susan Strongman