Smart Charging in Seattle


Seattle, Washington, has one of the highest adoption rates of electric vehicles (EVs) in the nation. With just over one percent of the nation’s population, the Seattle metropolitan area has eight percent of U.S. EV sales. There are over 12,000 electric vehicles registered in the state of Washington, more than half of which are in Seattle. With such a huge interest in EVs, this coastal northwest city is a perfect test bed to expand their use. That is exactly what Seattle’s utility, Seattle City Light, wants to do—increase adoption of EVs in the area, while harnessing the benefits EVs stand to offer customers and the larger energy system. The utility turned to RMI’s second annual Electricity Innovation Lab (eLab) Accelerator to help jump-start the program.

Smart Charging

While the program includes some commercial users, Seattle City Light wanted to focus on smart charging technologies for residential customers. There are 449 public charging stations in the state of Washington, the majority of which are in the Seattle area. The Seattle Department of Planning and Development has issued 394 permits for AC, level II charging stations in commercial zones. The city also has 14 chargers in city-owned or -managed garages that are open to the public, and there are six DC fast chargers located throughout the metro area. However, most EV owners still charge at home the majority of the time. With a smart charging network, the utility hopes to make it easier for customers to invest in EVs and provide more benefits in terms of charging.

Smart charging involves charging EV batteries (and in advanced vehicle-to-grid cases, discharging them) based on utility-, third-party-, and user-defined criteria (such as electricity prices and renewable energy output) while still maintaining sufficient charge to meet EV drivers’ needs. With smart charging, customers can charge their EVs in response to more granular price signals from the utility and so can sync with lower-cost times. This is especially important in Seattle as Seattle City Light doesn’t offer a special rate plan specific to EV drivers, as some other utilities do. “A smart-charging program can benefit both customers and the utility, as it allows charging during off-peak hours when the utility has excess power and prices are lower,” says RMI Senior Associate and eLab Team Facilitator Martha Campbell. In addition, “during the day, when solar panels are generating more power than consumers demand, the cars’ batteries serve as a sink to be drawn upon during a peak demand event. Smart charging creates what we refer to as ‘load flexibility,’ which is critical for maximizing EV benefits to the grid and consumers.”

Designing a Plan at e-Lab Accelerator

But going from the idea to actual implementation is the tricky part. “We had an idea of smart charging as an option, but we didn’t know exactly how to roll it out to customers and what a pilot project would look like,” says Jeff Bishop, CFO of Seattle City Light. That’s why Bishop, along with Michael Pesin, chief technology advisor for the utility; Andrea Pratt, green fleet coordinator for the city of Seattle; Gustavo Collantes, assistant director of the Policy Institute for Energy, Environment, and the Economy; and Jerry Weiland, managing director of RMI’s transportation practice, formed a team and joined eLab Accelerator.

At eLab Accelerator, the team developed a list of the main outcomes they want to see from a new EV program along with increased EV adoption—improved customer economics, emissions reductions, improved mobility, peak load avoidance, economic development, and increased consumer choice. To meet all these objectives, three main program elements need to be addressed: technology and infrastructure, enabling policies, and new utility business models.

Seattle City Light plans to roll out a small smart-charging pilot with the city’s EV fleet within the next couple of months to test the technology and explore the infrastructure that will be required to implement the program on a larger scale. The next stage after the pilot program will be to target public charging stations. “Utilities have a huge role to play in proliferating the adoption of EVs,” says Pratt. “They will benefit by selling more electrons, but they also have to be strategic as to the new load coming on to the grid.” Therefore, the pilot must be structured to test EV storage as a load reduction tool and an enabler of greater distributed energy resource (DER) integration.

New business models will take the form of new value streams for consumers and the utility. This will include determining the rate structure to use to provide more granular price signals. “A lot of studies and organizations are talking about what benefits EVs can bring to the grid,” says Campbell. “Understanding those benefits beyond their theoretical form and properly monetizing them will be key to creating a program with longevity while enabling the city to achieve its EV and DER adoption goals.”

There are also policy barriers that complicate a large-scale roll out of a smart charging program, notes Bishop. For example, since Seattle City Light is a public utility, it is more restricted in what it can do with ratepayer funds. The state also narrowly views incentivizing fuel switching, something utilities are not allowed to do, which makes promoting EV adoption a bit tricky for Seattle City Light.

However, Pratt believes that Seattle is the perfect place to roll out a program such as this. “Seattle is one of the best places in the nation to drive an EV. Our electricity is cheap and green.” In fact, Seattle City Light is one of the few utilities in the entire nation that is carbon neutral—90 percent of the utility’s electricity comes from hydropower, with the rest coming from wind and carbon offsets. And recently the governor signed into law legislation that allows utilities in the state to rate-base investments in electric-vehicle charging stations. This is an important enabling development that enhances Seattle City Light’s ability to embrace EV customers and help build out transportation infrastructure, something utilities historically haven’t done but will increasingly do as our transportation system electrifies.

Pratt is no stranger to electric vehicles. She manages 79 Nissan LEAFs, one of the largest municipal fleet of EVs in the nation, and her only family car (for her, her husband, two small kids, and two dogs) is also a Nissan LEAF. Seattle City Light invited Pratt to join the team at eLab Accelerator to share her local policy knowledge and on-the-ground experience with the utility as they navigate the space.


While the team originally thought of the three-legged stool as being composed of discrete elements, at eLab Accelerator the team realized it needed to engage many critical actors across the three program categories to design the most effective program. In other words, it needed to activate its rainmaking network. That’s the next step in the process, engaging all actors, from city officials to customers, and making sure the smart-charging program aligns with both the city’s and the utility’s ongoing EV initiatives. “At eLab, we took a concept and truly came up with a full plan,” says Bishop. “We fine-tuned how we would implement a pilot project, and how we would work with stakeholders, customers, and policy makers.” As smart charging becomes a reality in Seattle, the utility is poised to greatly accelerate EV and DER adoption. According to Weiland, “Seattle’s innovative EV pilot can help lead the way and show that EVs can be integrated into the grid with benefits to both customers and the utility.”

Image courtesy of the City of Seattle.