The mobile phone industry looks seriously for ways of manufacturing environmental friendly products.  A solar-powered mobile phone aimed at consumers without access to electricity goes into production later this month. The first phones to be manufactured will be sold in Papua New Guinea, Tonga and Vanuatu in June.

A market of 700,000 customers across Central America, the Caribbean and the South Pacific is predicted by Digicel Group, the mobile phone company that will distribute and provide network coverage for the phone. People in developing countries without access to electricity often pay brokers to charge their phones, according to Tom Bryant, director of procurement and distribution for Digicel Group, which is based in Jamaica. "It's a lifestyle necessity for many," he said. "But many of these brokers are expensive and you don't get a full charge either".

The new handset must be left in full sunlight for an hour to power a 15-minute talktime and is fully charged in around eight hours. Paul Norrish of G24I — a company in Cardiff, U.K., which has won World Bank awards for solar panels that can power several phones, and even lights is not sure, saying handsets are so valuable that people are unlikely to leave them in the Sun to charge. "People do not let their phones out of their sight. It's an interesting gimmick but I don't believe it is viable," he said.

There's so much interest in solar-power, particularly in Africa, says ZTE, the Chinese manufacturer building the handset, that it plans to create a range of solar powered phones. Samsung and LG have also unveiled solar phones in the last month. Creating a small, cheap, solar-powered phone that can charge in a reasonable amount of time is an engineering challenge, say manufacturers.

The greenest of mobile phones by far, the Samsung Blue Earth handset was on display at the Mobile World Congress. The phone has a touch screen front and a solar panel back, used to charge the phone. Fully charging the phone via solar power takes between 10 and 14 hours for four hours of talk time.

But is it realistic? Many of the 1.7bn people worldwide without access to electricity might be able to afford this handset's £29 price tag. ZTE's cheapest non-solar phone costs £18.