Poor parts of the world can be supplied with affordable solar power by 2020 through a combination of cheap technology and services provided by cell phone companies, argues Carl Pope, chairman of the US grassroots organisation Sierra Club.

Progress in technology, finance and business models is overcoming traditional barriers to getting renewable power to poor villages, he says. 'The combination of dirt-cheap solar, the cell-phone revolution, and mobile phone banking has changed everything'.

Conventional grid power and fossil fuels will not reach those who need it by 2030, according to Pope, and they are becoming more expensive. But cheaper and more sophisticated new technologies create an opportunity to pull together the resources needed to finance solar power for the poor.

Cell-phone towers around the world are being converted to hybrid renewable power sources, offering phone companies a 'powerful motivation to get renewable power into rural areas, to get electricity to their customers, and to charge for electricity through their mobile phone payment systems.'

Examples of innovative business models include Zimbabwe's Econet Power, which provides its cell-phone customers with solar power at US$1 a week with bills tied to a user's cell phone account.  

Providing the poor with off-grid renewable energy requires capital to buy solar power; business models that allow households to pay for what they use, making electricity less expensive than kerosene; and supply chains and distribution networks. 'The money is on the table. It's just on the wrong plates,' says Pope.

He calls for Rio+20 negotiations to embrace distributed solar power and replace kerosene, an expensive and dirty fuel. This would save 1.5 million lives every year (kerosene emits almost as much greenhouse gas pollution as the UK economy), raise income for the world's poorest fifth by 25–30 per cent, and create demand for expanding solar systems. And it could result in half of the world relying on renewable power, says Pope.