Pay-As-You-Go Solar Energy
= "just in the same way as you buy a scratch-card for your mobile phone every so often, you buy a scratch-card which enables your solar power to work for a period of time – for example a week or month, whatever it may be". 
- Eight19, http://www.eight19.com/
Simon Bransfield-Garth, CEO, interviewed by Olivia O’Sullivan:
"How does the system work in developing countries? How does solar power change people’s lives?
The solar-as-a-service model plays very well in emerging countries partly because the pay as you go model is well understood; people have pay as you go mobile phones. But also because we’ve eliminated the upfront cost of buying a solar light, so we can give people an economic return on a day by day basis. Where people don’t have electric light their options are kerosene or in some cases candles – about 80% of Zambia uses candles – and in South Sudan, for instance some people even just use grass as a way of lighting their houses. The amount of money people spend on kerosene for lighting is huge – about 38 billion dollars. When you compare the cost of that kerosene light for light with mains electric lighting, the light out of a typical kerosene lamp costs between a hundred and a thousand times as much – just because it’s a very inefficient lamp and kerosene’s expensive. So you end up with a situation where the people who have the least income in the world are paying not just a bit more for their energy but vastly more for their energy.
By providing solar we can eliminate that cost and replace it with something more modern and up to date. For example, in Kenya people are spending the equivalent of about 12 dollars a month for kerosene and for charging their mobile phone. We’re providing the IndiGo solar energy system for just over a dollar a week, so effectively for five dollars a month the user is getting light for two rooms and also power to charge a mobile. So we’ve roughly halved people’s energy spend and we’ve given them the benefit of solar power instead of kerosene.
What we find is that once people have solar power then it has a very dramatic effect on their daily lives. The light doesn’t just allow them to cook but it allows things like children to do their homework. Over time users can upgrade the system to progressively more powerful solar units. As you provide more power, you enable other things – such as access to a radio or a television – and so what the electricity is doing is providing key things that we’ve come to value in the more developed world like access to information and access to media; both of which have an important social impact, including the ability to participate in the political process. It’s much more than just providing light.
The fact that the weekly fee actually reduces users’ spend, by eliminating the cost of kerosene and charging phones, makes it much easier for us to sell into the market because we sell from the point of view of an economic proposition rather than just ‘solar-power is good’ – if you speak to someone who’s been living with kerosene for fifty years, sometimes it’s quite difficult to persuade them kerosene fumes are harmful things they don’t want to have. But if you say to someone who spends a quarter of their income on energy that they can halve their energy bill, then all of a sudden that has a direct impact – then after that they see the benefits of solar." (http://voices.nationalgeographic.com/2012/04/17/pay-as-you-go-sunshine-how-solar-energy-and-mobile-phones-are-powering-the-developing-world/)