Working Paper

City charging infrastructure needs to reach electric vehicle goals: The case of Seattle

This report evaluates the charging infrastructure needs for Seattle to reach its goal of having 30% of its vehicle stock be electric. It quantifies the number, type, and distribution of home, workplace, and public charging across Seattle and assesses several sociodemographic factors to inform more equitable deployment in the near term.

For Seattle, the vehicle demand-based charger need projection finds that meeting its goal requires approximately 2,900 public Level 2 chargers and 860 DC fast chargers to support 174,000 EVs on the city’s road in 2030, which is over five times more than the number of public chargers installed through 2019. In 2030, these EVs and the approximately 63,000 EV commuters from out of the city would consume approximately 1,530 MWh daily, or 10% of Seattle City Light’s average daily generation. In 2020, there are about 17 EVs for each public charger, and this ratio increases to about 47 EVs per public charger by 2030 as capacity increases in a maturing market.

In addition to the demand-based charger need projection, the report also conducts a geospatial multicriteria equity analysis to inform infrastructure planning. Comparing the two approaches reveals relative gaps and opportunities for more equitable near-term deployment of infrastructure. Targeted deployment in neighborhoods like Northgate, Olympic Hills, Delridge, and Beacon Hill will be important to expand infrastructure access and the associated economic benefits in priority communities. This comparison underscores the need for a multi-pronged charging infrastructure planning approach for more effective, efficient, and equitable use of public assistance.

City policies and programs can lower the EV charger deployment barriers and, when appropriate, fill the access gap and the market gap to prevent disparities from widening. For example, cities can create preferential and preapproved charger sites to promote investments in priority communities. Cities can also consider funding application-based residential curbside chargers for families meeting certain sociodemographic criteria in locations with a greater opportunity for charger sharing, such as areas predominately populated by apartments without off-street parking.