Conlog, a Schneider Electric subsidiary based in South Africa, is operating what is believed to be the world's first electricity prepayment vending environment that uses scratch cards. POWERcard is based on the GSM prepaid airtime concept. Cards of various denominations are produced and bought from the utility by vendors, who sell them on to customers. The value is redeemed by sending a text (SMS) message through online devices such as mobile phones. A 20-digit STS token is returned to the consumer's phone, and is entered into the meter.
When the electricity credit is depleted, consumers simply buy a new POWERcard from a convenient vendor. The benefit to the utility is guaranteed upfront payment by vendors; additionally there are no infrastructure costs, because the distribution network is already established through existing vendors. Customers benefit by being able to buy electricity 24x7.