Hawaii, with its population of nearly 1.5 million, had less than 7,000 electric vehicles registered across the state in January, mostly on Oahu.

But the Aloha State also has shown some of the strongest interest in so-called EVs in the nation, and the Hawaiian Electric Co. now believes that number will explode to more than 430,000 EVs on Oahu alone by 2045, Brennon Morioka, the utility’s general manager for electrification of transportation, said. 

If that number holds true, half of all the personal vehicles in Hawaii would be powered by electricity instead of gasoline within the next 30 years.

On Thursday, the state’s largest utility filed its so-called “Electrification of Transportation Strategic Roadmap,” a report to the Public Utilities Commission that discusses how the company, which provides power to five of Hawaii’s eight main islands, plans to meet that level of demand.

While 7,000 EVs might not sound like a lot, the report found that Hawaii already has the second-highest ownership of the cars per capita in the U.S. Only California has more.

Company officials on Wednesday described the coming spike in electric vehicle ownership as a “great leap forward” — a way to help them meet the state’s ambitious goal of generating all of its energy from renewable sources such as sun and wind by 2045.

It hinges on a critical change in behavior, however. In order to tap that renewable-energy potential, Hawaii’s EV owners need to start charging their cars during the day, when the sun is out and the solar is abundant, instead of at night, which is what most of those owners do now, industry analysts say.

A mass shift to daytime charging could open the HECO grid to as many as 200,000 private rooftop solar installations to help meet the new charging demand, according to Morioka.

“If we’re able to do it right, and to convince people to shift their charging behavior … that helps us get to the 100 percent (goal) quicker and cheaper,” Morioka said Wednesday.

The road map also calls for widespread installation of more charging stations across the islands to handle all the new EVs. Currently, there are 319 such stations on Oahu and 542 statewide, by Morioka’s count.

HECO is proposing the island add nearly 1,900 more in the next 27 years, bringing Oahu’s total charging stations to 2,200. Under the road map, HECO would own some and private third parties would own others.

The stations would dot Honolulu’s work centers and residential areas, and also be installed in rural areas, such as Waianae and the North Shore, so that drivers in town know they’ll have a spot to charge on longer drives around the island, Morioka said.

Further, HECO officials say the plan would eventually drive down its energy costs to customers.

The company has fixed costs for its poles, generators and other equipment that are approved by the PUC. If it sells more power to thousands of EV owners charging their cars instead of pumping gas, then the cost per unit for the grid’s electricity would go down. Then, HECO would have to lower the cost to its customers accordingly and keep revenues in line with the fixed costs, according to HECO spokesman Jim Kelly.

“EVs don’t pose a major challenge for utilities – it’s a market opportunity for them,” said Matteo Muratori, a transportation and energy system engineer with the Colorado-based National Renewable Energy Laboratory. “They’re in the business of selling electricity.”

Other utilities in the U.S. are also starting to capitalize, particularly in states that set targets for more EVs, Muratori said. Although he’s not familiar with Hawaii’s power market, Muratori added that it “sounds reasonable” that the EV charging would also make room for thousands more solar rooftop projects.

“What we are seeing is, as you apply more and more EV” you also get more solar panels, he said Thursday.  A recent pilot study in California led by BMW showed that EV owners will move to daytime charging if they’re offered price incentives, Muratori added.

“It’s sort of a business model question – how can you provide incentives to consumers,  Muratori said. “I don’t really see consumers being averse to providing that flexibility.”

Currently, about 90 percent of all EV owners charge at home, he added.

Morioka said it’s also in HECO’s best interest to push electric-vehicle use because it could save the utility from have to build costlier infrastructure to meet the state’s 100 percent renewable energy goal.

Local advocates for more EVs, such as the social investment fund Ulupono Initiative and the nonprofit Blue Planet Foundation have put their support for the HECO plan in writing. But they also believe that 430,000 number is conservative.

“In general, we’re very encouraged by those numbers — but we’re pretty sure it’ll be more than that,” said Lauren Reichelt, Blue Planet’s clean transportation lead.  The nonprofit has done its own analysis but Reichelt said Wednesday that the numbers aren’t ready to be shared.

Analysts predict that EVs will cost the same as traditional cars with internal-combustion engines by 2025. EV manufacturers haven’t really started to market and advertise their products yet to get a return on their investment, Reichelt said.  Once they do, EV ownership “could be above and beyond the projections,” she added.

California is poised to exceed its goal of 1.5 million EVs by 2025, and the state’s governor, Jerry Brown, has proposed 5 million of the vehicles by 2030.

Meanwhile, a measure that’s still moving through the state Legislature this year, Senate Bill 2955, would require the larger rental car companies in Hawaii to add EVs to their fleets. Any company with at least 200 rental cars would have to include at least 50 electric vehicles as part of their expansion plans through 2030, according to the measure’s description.

Eventually, Morioka said, HECO might also create incentives for EV owners to let the utility pull power from their batteries when needed while the cars are plugged for hours at a time.  This so-called “vehicle-to-grid” concept is still at least a few years away, but utility officials are testing it on Maui, Morioka said.

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