As Oahu braces for the 2022 closing of a coal-fired power plant that produces about a fifth of the island’s electricity, utility regulators have approved a program designed to help bridge the power supply gap with an incentive meant to help expand thousands of residential rooftop solar systems.

The program will provide cash to Oahu homeowners who install battery energy storage systems to new or existing rooftop solar systems, as long as the homeowners let Hawaiian Electric use the power stored in the batteries during peak hours, generally between 5 p.m. and 9 p.m.

Isaac Moriwake, an attorney with Earthjustice pictured in a 2017 photo, helped push a new program that will promote rooftop solar to replace a coal-burning power plant scheduled to close in September 2022. Matt Mallams/Earthjustice

“We’re talking thousands, not dozens or hundreds” of new or expanded solar systems, Public Utilities Commission Chairman Jay Griffin said in an interview. “So it’s going to have to mobilize quickly.”

Hawaiian Electric agrees that speed is key.

“We’re trying to get people to take action, so we’re trying to come up with a catchy name for it,” said Jim Kelly, the utility’s vice president for government and community relations and corporate communications, who declined additional comment.

The PUC issued the second in a series of orders related to the program late Wednesday. While Griffin stressed that much-needed industrial scale energy production projects are showing signs of progress, he said the EDRP program in effect responds to an oft-asked question: Why can’t Oahu simply replace the coal plant with more rooftop solar?

“That’s what we’re putting to test in real terms,” Griffin said. “But we’re not going to be putting all our eggs in one basket.”

Renewable energy advocates applauded the decision.

Isaac Moriwake, a staff attorney with Earthjustice in Honolulu who represented the Hawaii Solar Energy Association in the PUC proceeding, predicted the orders will spur renewed investments in solar systems.

“This is a first installment of the next big wave of rooftop solar and battery storage,” he said. At the same time, Moriwake said Hawaii will need large projects, and not simply more rooftop solar, to reach its goal of generating virtually 100% of the electricity sold in the state from renewable resources by 2045.

“To reach 100% we need all options on the table,” he said. “But what’s clear is to reach 100% we need to cover all rooftop space.”

Investors In New Systems Could Pocket Thousands

Colin Yost, chief operating officer of Revolusun, says Hawaii needs to pursue all options to make it to the 100% renewable goal. But Yost also said the new program “is different from anything we’ve seen before.”

As Yost described it, consumers can get an upfront payment from Hawaiian Electric for agreeing to sell the utility power from a battery for two hours per day, during hours to be determined by Hawaiian Electric, for 10 years. The amount of the payment would depend on the size of the battery, Yost said. But, as an example, he said the popular Tesla Powerwall would generate an upfront payment of $4,250 for a promise to sell power from the battery for 10 years. A Powerwall costs about $7,000, not including installation.

If people back out of selling power to Hawaiian Electric before the 10 years is up, they would have to pay back a pro-rated portion, Yost said.

What makes the program especially attractive, Yost said, is that the incentive comes on top of existing ones. So customers with existing systems can continue to sell excess energy back to Hawaiian Electric, according to terms of existing deals. The battery incentive would be on top of that, Yost said.

AES Hawaii Power plant coal burning electric powerplant located in Kalaeloa.
AES Hawaii’s coal-burning power plant is scheduled to close in 2022. The question facing industry leaders is how to mitigate the risk that the closure could lead to blackouts. Cory Lum/Civil Beat/2019

Still, it’s not simply a matter of signing up customers.

Rocky Mould, executive director of the Hawaii Solar Energy Association, said the new systems generally will require building permits, which could mean a flood of 10,000 applications or more over the next two years for Honolulu’s Department of Planning and Permitting to process.

“If permitting issues aren’t dealt with, this can be a significant roadblock to the program’s success,” Mould said.

Chris DeBone, who heads the Distributed Energy Resources Council of Hawaii, said the PUC’s orders are so new that several details of the program still need to be made clear.

“Everyone’s figuring this out right now,” he said. “There are still pieces of paper flying in the air.”

“But my first comment on this is it’s very exciting and it’s about time,” said DeBone, who is also a managing partner of Hawaii Energy Connection, a solar company.

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