Vehicle-to-grid Policy in South Africa: State-led v. Market-directed Approaches

Abstract

For economic, no less than ecological and energy security reasons, transitioning from coal to less expensive, cleaner, and more reliable renewable energy sources has become increasingly urgent for South Africa. Energy parastatal Eskom provides more than 90 percent of the country’s electricity, and depends on coal for more than 90 percent of its generation; yet this source is proving to be increasingly expensive and unreliable, with power reductions and outages costing more than 1 percent of GDP loss in recent years. While the country’s world-class wind and solar endowment has already proven to be less expensive than current (let alone new) coal and gas generation, it presents the challenge of intermittent generation, and thus of energy storage. This article presents the first exploratory study of a solution to South Africa’s energy storage challenge that would cost a fraction of the chronic blackout losses: the provision of bi-directional or Vehicle-to-Grid (or V2G) charging infrastructure, using electric vehicle (EV) batteries as complementary storage. Because South Africa’s current rate of electric vehicle uptake is low compared to most Organization for Economic Cooperation and Development (OECD) countries, we explore the option of providing V2G infrastructure to the most widely used subgroup of vehicles for mass transportation, minibus taxis. An additional advantage is that, because the minibus taxis are heavily concentrated in urban areas with relatively short commuting routes (well within the typical electric minibus range of 150-200 km per charge), the oft-cited “range anxiety” that prospective electric vehicle drivers face is far less of a concern. We model for the effect of V2G adoption v. the rollout of uni-directional EV charging infrastructure, while also comparing stipulated charging – using time slices (TS) to account for daily variation in demand, such as morning and evening commutes – to unstipulated charging. Whereas uni-directional infrastructure is less expensive, it does not afford the storage capacity of V2G infrastructure. With approximately 300,000 minibus taxis currently in use in South Africa, the combined storage potential of a completely electrified fleet would approach 6 GWh—almost twice that of the country’s combined pumped storage capacity.