Electric Vehicles

EPRI Study Examines Impacts Of Electrification For Seattle City Light

A new report from the Electric Power Research Institute (EPRI) lays out the potential impacts of electrification to Seattle City Light.

The City of Seattle has made significant commitments to address the climate crisis through greenhouse gas emissions reductions, and a key means of achieving those goals is electrification. As the utility serving Seattle and other nearby areas, Seattle City Light sought to understand the potential impacts of electrification in order to prepare to meet customers’ evolving needs.

The electrification assessment addressed two primary questions: How will electrification affect the utility's load over time and how can Seattle City Light’s distribution grid and resources best serve that load. To understand the city’s electrification needs, the study examined the high-level impacts of electrification under multiple scenarios that extend to 2042.

In particular, the study looked at the energy needed under three different scenarios for the electrification of buildings, transportation, and commercial and industrial applications, as well as Seattle City Light’s current grid load and capacity, and the utility’s projected future grid load. The study also examined the flexibility of new electric loads as a result of technology advances, and different strategies to help tackle the challenges of electrification.

At a high level, the study found that electrification will increase Seattle City Light’s load and that the impact to the distribution grid will vary based on time and location. Without energy efficiency or peak mitigation strategies, system peaks—driven primarily by changes in space heating, space cooling, and water heating consumption in residential and commercial buildings—are expected to increase significantly.

In the full electrification scenario, in 2042 residential and commercial buildings end-uses are projected to need over 60% of the total energy required annually. However, ongoing energy efficiency efforts could offset some of those increases, “which would ultimately help minimize electric system investment,” the authors said. In addition, advances in load management technologies and new technologies entering the market could provide greater load control and flexibility and help reduce peak demand when grid capacity is constrained.

Transportation electrification will represent a smaller portion of new electrified load, however, in a full electrification scenario, the energy required to fuel all electric vehicles would be about 90 times greater than current needs. Within the transportation sector, light-duty vehicles would represent the dominant load. Although heavy-duty vehicles consume more energy individually, the population of passenger vehicles is at least 20 times greater than any other vehicle class, the authors noted.

The study found charging needs of electric vehicles in Seattle City Light’s service territory will vary. Because there are a high number of multiple unit dwellings in Seattle, electric vehicle charging stations for end-users without a dedicated charger will need to be a priority, the authors said. Additionally, because of the aggregated depot charging and high-power charging that is required for medium and heavy-duty vehicles, it will be important for Seattle City Light to work with customers to understand emerging loads. Notably, much of electric vehicle charging is flexible load, and the impact will be highly dependent on customer behavior. EPRI identified this charging flexibility as an opportunity for Seattle City Light to mitigate the potential impact on peak loads.

On the grid side of the analysis, the study found that Seattle City Light’s distribution grid has “significant capacity available for additional electrified load,” but that in some areas and at some time of the day or year available capacity could be limited. It will be critical, the authors said, to be aware of when and where loads are emerging, and local monitoring and flexible load strategies “may prove key to ensuring that electric technology adoption is not limited anywhere” on Seattle City Light’s grid, they said.

Seattle City Light said that this analysis is the beginning of a larger undertaking to understand how it will plan for a decarbonized future and has already started to incorporate the results of the EPRI study to inform the public power utility’s other planning and forecasting efforts, including its Integrated Resource Plan and load forecast. Seattle City Light also plans to use the study to inform strategic objectives and policy and program decisions as it considers how to best facilitate equitable electrification.