CA Gets It that the Power System Must Manage EV Charging

18 Aug 2020

California’s heat wave-induced blackouts came during evening peak demand spikes. If California fails to manage electric vehicle charging it could make those spikes a lot more common, according to new research.

California leads the U.S. with nearly 750,000  of the estimated 1.5 million U.S. light duty EVs. Electric vehicle sales rose over 60% in 2019.  The Golden State’s goal is 5 million zero emission vehicles by 2030. But it will need 7 million to achieve its 60% renewables by 2030 goal, according to Southern California Edison.

The U.S. could reach 24 million EVs by 2028 and approach 30 million by 2030, according to July research by the Pacific Northwest National Laboratory. More conservative 2030 estimates by Edison Electric Institute—19 million EVs—and the Brattle Group—20 million— confirm a rapidly growing national charging load.

With 30 million electric cars, the U.S. power system’s peak charging load capacity could be overwhelmed. That is because EV owners are likely to charge their vehicles at home during the morning and evening peak demand periods, the Pacific Northwest Lab and others assume.

Unmanaged, the EV boom could add 10 GW/year to 20 GW/year of peak load nationally by 2030, according to new Brattle Group data. With its multiple zero-emission vehicles mandates, California would be a major contributor.

SB 676, signed into law by Gov. Gavin Newsom October 2019, reflects the urgency of managing EV charging by requiring state regulators to develop strategies to “maximize” its use.

The bill’s legislative guidance was incorporated into the California Public Utilities Commission Staff Feb. 3 proposed Transportation Electrification framework and the April 17 proposal from the California Energy Commission for Electric Program Investment Charge spending.

Managing the charging load with EV-specific time-of-use rates or other price signals can more than double peak charging capacity to 65 million light duty vehicles. This rewards owners for shifting their charging away from peak periods and makes it expensive to charge during peaks.

Unmanaged charging was common in California, Texas and Washington, New York, and in other EV markets,” Pacific Northwest Electricity Infrastructure Group Electrical Systems Engineer and study lead author Michael Kintner-Meyer told Current. “But the ability of EV-specific rates to move charging away from peaks was also seen in those markets.”

Factors that make managed charging planning urgent.

First, there will be an estimated 200,000 medium duty electric vehicles and 150,000 heavy duty EVs by 2028. They can draw unprecedented high loads through direct current fast chargers, which fully charge vehicles in about 30 minutes, according to June 2020 National Renewable Energy Laboratory research.

But those load spikes can be managed, NREL said. Truck stop-like charging substations should have the newest power conversion hardware and advanced algorithms to optimize the use of utility-scale renewables and storage.

Also, direct current fast charger loads from ride-share EV fleets or clusters of privately owned vehicles could cause thermal overloading and voltage violations on individual transformers. Price signals might address those issues but more aggressive management through vehicle or smart charger technologies might be necessary to stagger this clustered charging.

Managed charging reduces the total peak demand and flattens the sharp evening spike, the Pacific Northwest lab reported.

California’s recent rolling blackouts demonstrated the crucial importance of managing both. Rewarding EV owners for charging when prices are lowest also shifts consumption to when renewable resources are most abundant and drives demand for storage. Both support state mandates and policy goals.

Because of these benefits, “it is not a question of if, but when,” the Pacific Northwest’s Kintner-Meyer said.

There are nearly 100 specific policies that can advance managed charging in California, according to the state’s Vehicle-Grid Integration Working Group June 30 Final Report. Retail rate reform, development and funding of customer programs and incentives, and rules to access wholesale markets are the report’s top priorities.

“We definitely need managed charging to deal with grid impacts, but there is still a lot of work to be done on rate design, technology, and policy,” Vehicle Grid Integration Council Policy Director Edward Burgess said. “Too many utilities have not even begun to think about rate designs.”

California utilities are leading

The San Diego Gas and Electric Power Your Drive program’s time-varying rate pilot, which sends hourly price signals to drivers, is widely seen as the national standard in EV-specific price signal design.

The approach with the “most value and least cost” is an EV-specific TOU rate designed as “an incentive” to drivers, SCE  Senior eMobility Manager Eric Seilo stated in an email. PG&E spokesperson Ari Vanrenen and Sacramento Municipal Utility District spokesperson Lindsay Vanlandingham agreed.

Across the country, Maryland’s Pepco Holdings is starting managed charging pilots in advance of charging loads that “could be a risk to our system,” Pepco Smart Grid and Technology Project Execution Manager Jason Tucker said. “We don’t want to declare ‘no-charging’ times or face new infrastructure costs, so we are trying to shift charging behavior.”

Utilities, grid operators, policymakers, and standards agencies must take the lead, creating the right conditions for managed charging, including opening opportunities for private providers, VP of Energy Market Operations David Schlosberg for charger provider Enel-X North America told Current.

State planners need to address barriers to the challenges and benefits of accommodating new EV loads. “The three key questions are when, where, and how the vehicles will charge. Planners do not have the tools or methodologies to develop answers,” Kintner-Meyer said.

Third party providers like Flex Charging are showing that managing charging is possible, he added. They have developed business models that “use storage or other resources to procure electricity and service EV owners in ways that align with wholesale market prices and allow dispatch when its customers want it.” If utilities don’t provide that kind of service, it can be an opportunity for third parties.

Herman K. Trabish

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