By David Bornstein
To appreciate Fabio Rosa's Solar Home System, it's essential to pay attention to the details: when you are designing a business to deliver solar energy at low cost to an under-served mass market – as Rosa is doing in rural Brazil – there is no room for human error.
So the batteries must be protected with special boxes and numbered locks. And the plugs all have to be designed to fit one-way – because inadvertent reversal of polarity will damage the system. And finally – in an inspired touch – you may even decide to attach a miniature sculpture of a saint to the battery box – just to serve as a daily reminder to the customer that the battery – the energy store – must be treated as sacred.
Two billion people – about 30 percent of the world's population – lack access to electricity. And it is estimated that about one billion of them can afford solar energy today at commercial rates – given their current energy expenditures – provided that they are given the option to rent it or pay it off in installments over several years. Bringing solar energy to a billion people would stimulate economic activity, improve education and health, reduce carbon emissions and relieve stress on the world's overcrowded cities.
