Hawaii lawmakers are on the cusp of putting new parameters on renewable energy generation in the state that cap power produced from different technologies including wind and solar.

A bill passed by the Legislature earlier this month and awaiting action by Gov. David Ige aims to amend the state’s energy policy so that it prevents more than 66.67% of power being generated from all combined intermittent sources such as wind, waves and sun.

Conversely, at least 33.33% of electricity statewide would have to be from “firm” renewable sources — such as geothermal, hydroelectric and incineration fueled by biomass or garbage — that can produce energy 24 hours every day outside of maintenance or emergency repair periods.

Another provision in Senate Bill 2510 limits any single type of renewable energy to 45% of production per island, except for geothermal power.

SB 2510 was highly debated at the Legislature, and even now stirs disagreement over whether the measure, if it becomes law, would impose such caps or only make them policy objectives.

Sen. Donovan Dela Cruz, the bill’s lead introducer, said the bill would not force the state Public Utilities Commission, which is in charge of approving or rejecting new utility-scale power generation projects, to impose requirements stated in the legislation.

“This measure is not a mandate to the PUC,” Dela Cruz (D, Wahiawa- Whitmore-Mililani Mauka) said in a Senate floor speech May 3 as the bill received final approval in the Senate and House via moderately split votes. “It is a policy and planning document. It states goals.”

Jim Kelly, vice president of government relations for the state’s biggest utility, Hawaiian Electric, expressed a different view.

“The bill talks about requirements, not goals, so we’re assuming compliance isn’t optional,” he said in a statement.

The stated purpose of SB 2510 is to “establish a state energy policy that requires” at least 33.33% of renewable energy be firm renewable energy that replaces fossil fuel energy and achieves 100% renewable energy generation by the end of 2045, and to “amend other statutory provisions to achieve” at least 33.33% firm renewable energy generation for each island.

The prescribed change in state law is directed at Hawaii Revised Statutes Section 226-18, which governs energy system planning and policies for achieving objectives that include reliability, security, diversification, greenhouse gas emissions reduction and making customers’ financial interests a priority.

To this list would be added several things, including the replacement of fossil fuel generation with firm renewable generation that “shall be” a minimum of 33.33% of renewable energy generation for each island.

Another objective is to limit the percentage of any one type of renewable energy source to 45% of all generation for each island, except for geothermal-generated energy.

The bill allows the Legislature to change these stated percentages by adoption of a concurrent resolution based on study data from the Hawaii Natural Energy Institute.

In February, Richard Rocheleau, the institute’s director, told a Senate committee that it would be premature to limit any type of renewable energy, or amount of intermittent renewable energy, because it’s not known how much variable renewable energy can power electrical grids in Hawaii given evolving technology.

Other critics of the bill included the state Energy Office and the state Office of Planning and Sustainable Development.

Supporters of the bill include petroleum refinery operator Par Hawaii and Maui-based Pacific Biodiesel Technologies.

Honua Ola Bioenergy, developer of a nearly complete wood-burning power plant on Hawaii island awaiting a PUC decision on whether the facility should be allowed to operate, did not testify on the bill, but recently has been touting the need for firm renewable energy in advertisements.

Tawhiri Power LLC, a wind farm operator on Hawaii island, called limits for renewable energy technologies a step backward.

“I really think you are doing a disservice to the state and its residents by boxing yourself in,” Sandra-Ann Wong, a Tawhiri attorney, told a Senate committee in February. “That just perplexes me on why you would want to box yourself in now at this time versus keeping all of your options open.”

Hawaiian Electric, the regulated utility for every county except Kauai, warns that limiting any one type of resource will make it more difficult to reach the state’s goal to produce 100% of electricity from renewable sources by 2045.

In 2021 the biggest concentration of renewable energy for Hawaiian Electric was about 21% solar power on Oahu, followed by 20% wind power and 19% solar power in Maui County and 15% solar power on Hawaii island.

Kelly said the utility company anticipates that solar energy could grow to well above 50% on Maui, Lanai and Oahu in the next few years.

On Kauai, where the nonprofit Kauai Island Utility Cooperative operates the electrical grid, the power mix in 2021 was already at 45% for solar.

David Bissell, KIUC president and CEO, told lawmakers in March that prescribing specific percentages of any type of renewable energy could create significant challenges for the company.

KIUC is developing a combination hydroelectric-solar power plant to reach 90% renewable energy generation on Kauai by 2025. After that the only envisioned viable option for the remaining 10% is solar power with batteries, an intermittent power source, unless technology significantly evolves over the next decade, according to KIUC.

“It is vital that utilities seeking to meet the state mandate of 100% renewable by 2045 be offered the greatest flexibility possible in employing technologies that are compatible with the geographic, social, and environmental characteristics of the areas they serve,” Bissell said in written testimony on SB 2510 in March while the bill was still being considered by Senate committees.

At that time, the pending draft of the bill called for 55% of renewable energy to be firm, compared with 33% in the bill’s final version, though the 45% limit for any single type of technology was the same.

After the bill crossed to House committees for consideration, all references to minimum or maximum amounts of renewable energy were excised.

But then at a House- Senate conference committee meeting April 29, House negotiators agreed to the Senate’s position for minimum and maximum levels.

“There are some things that are concerning, but we’ve agreed to agree and move forward,” House conference committee Chair Rep. Nicole Lowen (D, Holualoa-Kailua-Kona-Honokohau) said at the meeting.

On May 3 the House voted 39-12 to approve the bill, and Lowen restated her support, prefaced with a sigh.

Among those who voted against the bill were Rep. Angus McKelvey (D, Lahaina- Kaanapali-Honokohau) and Rep. Tina Wildberger (D, South Maui).

McKelvey said solar is still important for meeting renewable energy needs and that the total intermittent power limit could preclude technologies on the horizon such as wave power.

“I think we’ll have an unintended consequence,” he said on the House floor.

Wildberger said SB 2510 seemed to be in conflict with another bill lawmakers passed this year to establish a greenhouse gas emissions reduction goal.

“We just really got to stop burning stuff if we want to reduce our greenhouse gasses,” she said.

Rep. Bert Kobayashi (D, Diamond Head-Kaimuki- Kapahulu) voted for the bill, which he called defective.

“The bill does not have teeth,” he said. “It is not regulatory. It does not stop anyone from going to more renewables, because it only amends the state plan.”

On the Senate floor, Dela Cruz defended the bill as providing a plan to reach a balanced mix for Hawaii’s energy future.

“We cannot be overly dependent on one source of any technology,” he said.

Sen. Glenn Wakai (D, Kalihi-Salt Lake-Aliamanu) said there needs to be a balance between intermittent and firm renewable energy.

“SB 2510 gets us to a better place,” he said just before colleagues voted 20-5 to pass the bill.

Ige has until June 27 to notify the Legislature about any bills he is considering for a veto and has until July 12 to veto bills. He has not stated a position on SB 2510.