Feasibility of Electric Vehicle Adoption in US Ambulance Fleets: A Retrospective Analysis of NEMSIS Data

The transition to electric vehicles (EVs) represents a potential strategy for reducing carbon emissions from the health care sector. Ambulances, however, have unique operational demands, including rapid response times, variable call volumes, and prolonged periods at hospitals. Using data from the National Emergency Medical Services Information System (NEMSIS) in 2024, we modeled the feasibility for implementing EV ambulances in multiple response environments, as well as the possible benefits of providing at-hospital charging at various speeds.

We used an observational study design and retrospective analysis to assess the average time on task and estimated driving distances for EMS 9-1-1 calls stratified by urbanicity. These ranges were tested against two hypothetical operating profiles of electric ambulances to assess practicality, assuming a 25% remaining battery capacity at hospital arrival. Potential models for at-hospital charging were evaluated using different charging rates.

Estimated mileage fell within range requirements for most cases, ranging from 99.9% of dispatches for urban settings with a higher-capacity vehicle to 97.6% of dispatches in frontier settings for a lower-capacity vehicle type. Assuming charging time to span from ambulance arrival at hospital to return to service, both Level-2 and Level-3 charging stations restored significant fractions of total energy used during transport.

Electric ambulance battery capacity ranges cover the majority of distances required by single dispatches across multiple urbanicity settings, but higher-capacity battery vehicles may be more consistently reliable in rural or frontier settings. Incorporating at-hospital charging stations may offset a significant portion of charging time requirements. Benefits of reductions in vehicle emissions likely differ according to local power grid composition.