Pay-as-you-go solar aims to bring affordable electricity to rural Africa . The system -- which can light two small rooms for seven hours at a time and charge small portable devices such as mobile phones -- has been designed and manufactured by British based solar technology company , Eight19 . Score: 6 Service allows users to light their homes for as little as $ 1 a week .
Pay-as-you-go solar aims to bring affordable electricity to rural Africa . Score: 6 Service allows users to light their homes for as little as $ 1 a week .