Approximately 7-million prepaid electricity meters in South Africa need to be reset before November 2024 as the system that runs the credit tokens will run out of numbers at this time and all existing meters will stop accepting credit tokens.
The South African metering standards industry body, Standard Transfer Specification Association (STSA), has embarked on an awareness programme to inform utilities to upgrade their vending systems to STS600 and visit each meter in its region to clear the memory and change the meter key before November 2024.

Don Taylor, director of STS Association, explains: “The token identifier (TID) is calculated as the number of minutes that have elapsed since a defined base date of 1993 up to the time of creating the token. The TID has a limited range and will run out in November 2024, at which point all existing prepayment meters will stop accepting credit tokens.

“In order to circumvent this issue, the memory of each meter needs to be cleared of all stored TIDs and its cryptographic key needs to be changed before 2024.”

The new range of TIDs will then start from a new base date of 2014 and run out in 2045, thus extending the useful functional life of the meter. “In order to do this key change,” Mr Taylor explains, “it is necessary that each meter has to be physically visited, which can be performed either by dedicated employees of the utility or by the end customer.

“There is thus a six-year window, within which the utilities have to complete this programme,” he adds.

“Because we are concerned that utilities may leave this too late, we are embarking on an awareness programme by reaching out to all STS users and providing a platform that will facilitate technical support and guidance to users during the implementation of the TID rollover programme.

“We aim to establish a website for this purpose where users can interact by discussion of issues. In addition we are embarking on a communication effort with users by making use of media channels and conference events in order to raise awareness of the 2024 TID rollover. This programme is being managed by a specially mandated task team.”

STSA estimates that approximately 7-million prepayment meters are currently installed in South Africa, which could still grow to approximately 8-million by 2024.