One of London's famous red telephone boxes has been painted green and transformed into a solar-powered charging station. The so-called “Solarbox” can be found in central London's Tottenham Court Road and five more will be unveiled by April 2015.

The Solarbox provides 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, offering a 20% battery boost in 10 minutes. The service is free to use although users will be shown adverts as they wait for their phone to charge.

The project was designed by two geography graduates, Harold Craston and Kirsty Kenny, from London School of Economics (LSE). 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. Craston and Kenny indicated that 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. “Since launch, about six people per hour use the booth,” they said.

Funded by advertising, the founders are keen to make sure users are engaged by "short, fun and exciting ads showing exclusive content". Firms signed up include Tinder and Uber, and 30% of advertising space is reserved for community projects.

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.

Photo Credit: Huffingtonpost