This is the third of a three-part series covering analyses that were part of the Energy Transition Initiatives Partnership Project which was a Department of Energy funded program in the form of technical assistance for the County of Kauai.
Electric Vehicle (EV) Charging Study Summary –
The researchers and technical assistance team working on the Energy Transitions Initiative Partnership Project (ETIPP) were tasked to assist the County in quantifying the electric vehicle charging demand of Kauai’s future light duty vehicle fleet, considering the State and County’s goal to reach 100% renewable ground transportation by 2045.
GPS app-based location data collected on cellphone devices of residents and visitors provided information on trip distances and daily vehicle miles traveled, with residents averaging 17.6 miles a day and visitors 19.3 miles a day. The findings indicate that only destination chargers (home, public/workspace) and not midtrip chargers are necessary. The same conclusion was reached in using the HDOT Kauai Travel Demand Model for 2035 projections.
Diving into the analysis, future residential charging access considerations include travel demand data, obtained considering varying data points, as well as housing age, housing type, parking by housing/tenure type, and outlet availability by parking type/building age. Information on these factors was collected via nationwide and local surveys, and data from the County Building Division.
The study shows the amount of residential charging sessions in one day projected against existing and potential electrical access using Level 2 charging stations and Direct Current Fast Charging (DCFC). The key difference between these two chargers is how fast each will charge an EV’s battery, and subsequently, the amount of power drawn. Concluding findings show that the potential higher-bound electrical access would result in a nearly 50% decrease in charging sessions for both types of charging stations across four different electric vehicle adoption scenarios.
Researchers used existing travel demand data and NREL’s Electric Vehicle Infrastructure Projection Tool (EVI-Pro) to map out the number of charging ports needed per planning district, for four different scenarios, considering a gradual 25% increase in electric vehicle adoption, with lower-bound and higher-bound existing residential electrical access. Findings indicated that by a large margin, Lihue will need the highest number of public EV charging ports, followed by East Kauai and Koloa-Poipu-Kalaheo, then the North Shore, Hanapepe-Eleele, and Waimea.
The district level estimated charger counts were as follows:
Level 2 Charger Counts –
DCFC Charger Counts –
For more information regarding the methodology, analyses, and findings, the published study can be found here – https://kauaiforward.com/wp-content/uploads/2024/09/Deliverable-11-Task-3-EV-Charging-Network-Analysis-Summary.pdf
-Clarissa Hsi, Climate Communications VISTA, Office of Economic Development, County of Kauai
