A Secure Web Service for Electricity Prepayment Vending in South Africa: A Case Study and Industry Specification

Current standardised offline vending systems play a critical role in supporting electricity prepayment-metering infrastructure by enabling convenient access to point of sales for customers to purchase prepaid electricity tokens. Electricity utilities are now opting for online vending systems over offline vending systems. Online vending represents a step change in prepayment vending systems, which promises several benefits to utilities. However, the lack of an industry specification for online vending systems was a cause of major concern and risk for utilities, as they faced the problem of being locked into proprietary online systems. Further, the unchecked proliferation of proprietary online vending systems would have a detrimental impact on already successful standardisation efforts in the electricity prepayment industry. Thus, the South African prepayment industry, initiated a project to develop an open industry specification for online vending systems. This paper analyses the industries migration to online vending systems, the specification development process, the design issues that emerged and implementation of the specification as a Web service.