How electric cars could affect state grid

How electric cars could affect state grid
If electric car ownership increases, so will the energy demand on the state grid. A pilot project by Avista and other studies highlight the challenges and potential solutions. Photo:

A bill introduced this session would require all new cars sold starting in 2030 to be electric vehicles (EV). Although the legislation failed to clear its original committee before the legislative cutoff date following a Feb. 10 public hearing, policymakers and utilities continue to explore the potential impact of EVs not only to existing transportation infrastructure, but also to the state’s energy grid which is already planned to make a major transition toward clean energy as part of the 2019 Clean Energy Transformation Act (CETA).

A presentation by the Washington Utilities and Transportation Commission (UTC) to the Washington State Transportation Commission (WSTC) at its Feb. 19 meeting examined, among other things, the findings of a 2019 report put out by Avista on its three-year Electric Vehicle Supply Equipment (EVSE) pilot project. Similar studies have also been conducted by Puget Sound Energy and Pacific Power.

Avista provides natural gas and electricity in eastern Washington, and its report offers charging data collected from the pilot that UTC officials said can help guide grid expansion to accommodate more EVs.

“Electrification of transportation is both a blessing and a curse for the utilities,” UTC Senior Policy Advisor Brad Cebulko told the commission. “It has the potential to grow their revenues, but it also has the potential to cause great disruption if too much load comes on and you can’t manage it.”

Reflecting the difficulties of existing state mandates is a proposed change to CETA requiring the state Department of Commerce to regularly study the electrical system as utilities switch to clean energy sources. A bill provision allows utilities to halt implementation if it threatens grid reliability or stability. SB 6135 on Feb. 17 received unanimous support from the state Senate and is scheduled for a Feb. 25 public hearing in the House Environment & Energy Committee.

There are currently 42,000 EVs in the state; more than half of which are located in King County alone. A 2017 report by Wood Mackenzie found that by 2035 U.S. EV energy demand will increase dramatically due to a combination of government policy as well as reduced battery costs. That same year, the UTC issued a policy statement noting that “there is no consensus on the ‘right’ model to accomplish market transformation, and flexibility is essential at this early stage.”

The UTC report also emphasized prioritizing the ability to manage energy demand loads. For comparison, the typical EV uses between 3,000-4,000 kilowatts (kWh) a year, while the average Washington household consumes 12,000 kWh annually. In 2015, the state legislature approved ESHB 1853 stating that utilities “must be fully empowered and incentivized to be engaged in electrification of transportation system.”

On one hand, Cebulko said that revenue derived from EVs can shoulder some of the capital costs to expand overall grid infrastructure. Yet, the Avista report underscored the challenge that increased EV usage can have if that added demand isn’t spread out more evenly. For the three-year pilot, a total of 439 charging ports were installed at 226 homes, 123 workplaces, and 20 multifamily residences, along with seven DC fast-charging sites.

The report concluded that the existing grid could handle EV energy demand for the next decade, and the vehicles “offer the potential to provide significant economic and environmental benefits for the long term.”

However, the 53,000 charging sessions analyzed showed that EV drivers tended to charge their vehicles at work during the day but primarily in the evening between 5-7 p.m. Similar trends were reported in a 2017 U.S. Department of Energy analysis.

“That’s the problem,” Cebulko said. “It (charging sessions) also coincides with the peak demand for the utility. We’re going BOOM for that last hour, and that’s really expensive.”

He added that one potential way to address that is shifting more EV charging sessions to midday when energy rates are lower. “You can import power from California, or our own local sources that would normally be selling to California. That’s the opportunity.”


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