Siting for demand and equity: Optimizing level 2 electric vehicle charger placement

Governments and automakers are accelerating the transition to electric vehicles (EVs). However, a key barrier to widescale electrification is the lack of access to the supporting electric vehicle supply equipment (EVSE). A bi-objective optimization model is developed and applied to Pittsburgh, PA and Seattle, WA as case studies, to illuminate how stakeholder preferences towards equity (i.e., improving EVSE access for disadvantaged communities) impacts the spatial distribution of EVSE. Performance metrics, including EVSE coverage, average number of nearby EVSE, and average number of households per EVSE, were evaluated across seven demographic groups: White, Asian, Black, Hispanic, low income, medium income, and high income households. In Pittsburgh, the results revealed that at lower budgets, changes to stakeholder equity preference had minimal impact on demographic access to EVSE. At higher budgets, prioritizing equity leads to higher access, coverage and less overcrowding for low income and minority households, at the expense of high income households. In Seattle, equity-focused strategies consistently improved outcomes across all demographics. High income households, being geographically dispersed, still benefited when equity was prioritized. In both regions, the most balanced outcomes were achieved when there was a neutral preference for equity. The findings suggest that while equity-focused strategies can improve access for underserved demographics (e.g., low-income and minorities), the optimal strategy varies based on budget and city-specific characteristics (e.g., existing EVSE placement, population density and spatial distribution of different demographics). The study underscores the importance of considering demographic equity in EVSE deployment to ensure widespread and fair access to EVSE.