Idle occupancy and dead piles: new challenges in public charging station promotion

Abstract

<p>As a sustainable and efficient means of mobility, new-energy vehicles are increasingly favoured. The rapid growth of these vehicles requires more attention to the construction and operation of charging infrastructure. However, the development of charging infrastructure faces multiple challenges. A mismatch exists between high construction costs, low utilisation rates, an expanding market size and increasing charging demand. Moreover, this emerging vehicle refuelling brings about new issues, such as idle occupancy and dead piles. These challenges can reduce the turnover rate of public charging stations, leading to resource wastage. Therefore, it is crucial to comprehend the dynamics of idle occupancy and dead piles, along with their potential impacts, to optimise the operation and management of the charging facilities. This study marks the first attempt to investigate charging failures and their effects on station utilisation using charging status big data, based on Shenzhen, a pioneering city in vehicle electrification with a dense network of public charging stations. The descriptive analysis and regression results indicate widespread idle occupancy, with substantial temporal variations and spatial clustering. Furthermore, idle occupancy and dead piles in the previous hour reduce the charging rate at the same type of charging stations in the following hour. At fast-charging stations, idle occupancy and dead piles increase charging pressure in the surrounding area. In contrast, at slow-charging stations, idle occupancy and dead piles prompt users to shift towards fast-charging alternatives. Additionally, lower socio-economic groups experience higher idle occupancy rates. As a systematic and empirical exploration of charging failures, this study provides evidence to guide the planning, operation and management of charging infrastructure, thereby further promoting the development of the new-energy market.</p>