- London's red phone boxes are being turned into a solar-powered phone charging boxes
- Two design entrepreneurs are behind the idea, which is being rolled out across the city
- It's not the first time traditional phone boxes have been given a modern lease of life
- Others have been turned into libraries, sofas and shower booths
Next time you're on the go and your phone is running out of juice, try a phone box. No, not for calling. To charge your phone.
One of London's famous red telephone boxes has been painted green and transformed into a solar-powered charging station, as part of a design competition.
The so-called "Solarbox" can be found in central London's Tottenham Court Road, and there are plans for more to be opened by early 2015.
The Solarbox has chargers for Samsung, BlackBerry and the iPhones 4, 5 and 6. It can power an estimated 100 devices a day through its roof-mounted solar panel.
It was designed by London School of Economics graduates Harold Craston and Kirsty Kenney, in response to a competition run by the Mayor of London.
Their eco-friendly invention won them $8,000 and a spot in a mentorship scheme in the Mayor's Low Carbon Entrepreneur competition, making it possible to pilot their new business in London's streets.
The kiosk funds itself by advertising, and using the service is free. Its inventors say the costs to run the machine are low -- it requires only basic maintenance such as cleaning, and initial costs of installing each Solarbox is forecast to be recouped within three months.
The two wanted to use their interest in renewable energy to provide a service that people would really need. "We've all been caught out -- phone battery life just can't keep up with the pace of our modern lives," Kenney said.
"By using solar power and repurposing old phone boxes we have been able to provide a real solution in an environmentally friendly way," she said.
The rise of the smart phone has made thousands of the UK capital's phone boxes redundant, except for tourists looking for photo opportunities.
The Solarbox is not the only unused phone box to be transformed into a new creation -- there are phone box libraries, sofas and even shower booths.
Redundant phone boxes in Sydney, New York and other cities are being turned into free Wi-Fi hotspots, while several villages in England have equipped theirs with defibrillators.