
A fast-charging station near Seattle's Pioneer Square. The city, predominantly powered by hydroelectric dams, Source: S&P Global Market Intelligence |
With hydroelectric generation accounting for more than 90% of Seattle City Light's power mix, the Pacific Northwest's largest city has some of the least expensive electricity in the United States and one of the world's lowest-carbon grids. Now it is developing a plan to tap that power system to decarbonize its transportation sector.
Seattle City Light and non-profit consulting group Rocky Mountain Institute on Sept. 4 released a roadmap for Seattle to prepare for a surge in power demand from electric vehicles, or EVs. The city has established goals of electrifying 30% of all vehicles and developing a fully carbon-free municipal fleet, both by 2030.
With EVs already representing around 5% of all new vehicle sales in Seattle, the city ranks among the top U.S. cities for EV adoption outside of California, the report said. Without a strategy for charging all those vehicles, however, Seattle's grid could be overwhelmed.
While increased personal electric vehicles and charging "are not anticipated to pose much risk for City Light to accommodate given its current grid capacity," large "spot loads" from electric buses, medium-duty and heavy-duty vehicles "have the very real potential to overwhelm available capacity and require grid upgrades," according to the report.
"Investing in charging infrastructure and proactively engaging with fleet and transit customers are two of the most important ways that City Light can accelerate the transition to electric vehicles in Seattle," Brendan O'Donnell, manager of planning, strategy and analytics at Seattle City Light, said in a news release.
Smart charging
For Seattle City Light and other utilities with ambitious electrification plans, managed charging is needed to avoid unnecessary peaking generation investments, found another recent report.
The Seattle City Light study recommends "smart charging" during periods of low power demand and using electric vehicles as flexible grid assets. And it urges the utility to prepare for heavy-duty electric vehicles by partnering with municipal transit agencies, the Port of Seattle and Washington State Ferries to offer special rates and incentives, building new infrastructure and providing technology demonstrations.
Electric buses are emerging as heavy electricity consumers. King County Metro, the public transit agency that serves the Seattle area, plans to order 120 electric buses by 2020 and electrify all 1,400 of its buses by 2040.
The report also recommends building utility-owned direct-current fast-charging stations and grid upgrades to support private fast-charging networks, providing incentives for chargers at homes and businesses and launching a pilot program for special charging rates.
Citing falling lithium-ion battery costs and the growing availability of EVs, the report said vehicle costs "are soon to reach a tipping point." Moreover, the city has low electric rates, around 11 cents/kWh, compared to its relatively high gasoline prices, meaning that "Seattle's electricity–gasoline price differential is more favorable to EVs," according to the report.
A previous study for Seattle City Light identified a net benefit to the utility's system of $1,250 per electric car over the vehicle's lifetime.
