North O`ahu Wind Farm Wins License To Incidentally Kill Protected Bats, Birds

posted in: June 2018 | 0

On May 18, the majority of the state Board of Land and Natural Resources rejected its hearing officer’s recommendation to deny a Habitat Conservation Plan (HCP) and Incidental Take License (ITL) for the proposed 25-megawatt Na Pua Makani (NPM) wind farm in Kahuku, on O`ahu’s North Shore. Instead, the board backed its own team of experts with the Endangered Species Recovery Committee (ESRC) and the Department of Land and Natural Resources’ Division of Forestry and Wildlife (DOFAW), which both recommended approval in 2016.

Mike Cutbirth, manager of Na Pua Makani Power Partners, told the board in 2014 that the project will be the “lowest cost wind energy project in the history of Hawai‘i,” and that it will contribute $2 million to a community benefit fund as long as it’s operating.

Despite the wind farm’s obvious benefits to the state’s renewable energy portfolio, the non-profit Keep the North Shore County (KNSC) and some Kahuku residents opposed the facility. Some complained that the facility would be too close to homes — within half a mile — while others worried about the potential effects the spinning turbines would have on endangered native bats and birds. The HCP and ITL came to the Land Board for approval in November 2016, but KNSC and Kahuku resident Elizabeth Rago requested and were later granted a contested case hearing on the matter.

After taking evidence and witness testimony the following year, hearing officer Yvonne Izu released her proposed findings of fact, conclusions of law, and decision and order last October. She mainly found fault with the HCP’s treatment of the endangered Hawaiian hoary bat, which has been killed in unexpectedly high numbers by wind farms throughout the state.

Izu questioned NPM’s decision to use the adjacent Kahuku Wind project as the sole surrogate for estimating the total number of incidental bat deaths likely to occur during the 20-year life of the project, despite the ESRC’s position that this approach was appropriate. Based on the Kahuku project’s low level of bat deaths, NPM anticipated that it would take 34 to 51 bats during the life of the project. However, Izu wrote that the company should have analyzed bat mortality at other wind farms in the state that had been operating longer than the Kahuku project.

Izu suggested that NPM had failed to factor into its bat take estimates the possibility that its much-taller turbines could kill more bats. She also found that NPM’s plan to start spinning its blades only when wind speeds reached a minimum of 5 meters per second (again, following ESRC guidance) fell short of the state endangered species law requirement that the facility minimize and mitigate its effects to the maximum extent practicable.

“[T]he best scientific knowledge currently available suggests that increasing cut-in speed to 6.5 m/s, rather than 5 m/s, would minimize impacts to the maximum extent” and NPM failed to prove that the higher cut-in speed was impracticable, she wrote.

Sole Proxy

In its 98-page decision, the Land Board detailed its many reasons for supporting a permit and take license for the wind farm. The board rebutted Izu’s contention that using the Kahuku facility as the sole surrogate was inadequate. Instead, it determined that the Kahuku wind farm was, in fact, a suitable model upon which NPM could base its estimated bat take.

To start, the Kahuku facility is less than a quarter mile from the NPM site and has similar terrain.

KNSC contended that the HCP should have considered bat take data from the Kawailoa wind farm, which is about 4.5 miles distant, lying between Haleiwa and Waimea Bay. The Land Board disagreed.

As of mid-2015, that much larger wind farm, which consists of 30 turbines compared to Kahuku’s 12, had more observed bat fatalities than the other five wind farms in Hawai`i combined, the board noted, adding that the Kawailoa site also had about ten times the bat activity of Kahuku.

The board also pointed to a study of the Ko`olau mountains completed a few years ago, in which researchers detected bats less often in the windward northern areas (such as the Kahuku and NPM sites) than in the leeward southern parts of the study area (where the Kawailoa farm is).

Citing comments by ESRC members that the Kawailoa facility was an “outlier” with its high number of bat deaths, the board concluded that the preparers of NPM’s plan “consciously, and correctly,” chose not to incorporate any Kawailoa bat take data in its estimates.

Height, Rotor-Sweep

The board also concluded that scientific evidence presented during the hearing failed to prove a direct correlation between turbine height/rotor-sweep area and bat mortality at the elevations of the NPM turbines. And even if there were such a correlation, the board found, “the conservative assumptions made by the NPM HCP would more than accommodate an adjustment based on the greater height and rotor sweep area of the NPM turbines vs. the Kahuku turbines.”

With regard to a 2007 study that showed that taller turbines killed more bats, the board suggested it was only because the taller blades in that case reached high enough to interact with migrating bats. “This may not necessarily apply to the ope`ape`a, which do not migrate,” the board wrote.

The board also cited a 2009 study, which stated that fatality rates would be low at sites with little bat activity (i.e., Kahuku and NPM) because “there are few bats to be killed, and tower height is inconsequential. (emphasis in the original).”

“The remaining sources cited for the proposition that bat take increases with height are secondary (in the sense that they rely on other studies),” the board wrote, adding, “Without more, we cannot conclude that these studies demonstrate a difference due to the height differences between Kahuku and NPM.”

The board acknowledged that it was plausible that more bats would be killed with a larger rotor-sweep area. However, “the two studies in the record which directly address this question came to contrary conclusions,” the board wrote.

In any case, the board noted that the HCP already estimated the number of expected bat deaths by 20 percent over what it would be using the statistical analysis employed at Kahuku. What’s more, the board took into account NPM’s announcement late in the hearing that it was reducing the total number of turbines from nine to eight. “This would cause an 11 percent decrease in the expected take calculated on a per-turbine basis,” the board wrote.

The board also found that the NPM and Kahuku facilities would have similar total rotor-sweep areas, with NPM having fewer, but large turbines, and Kahuku having more, smaller ones. Given that the Kahuku facility has averaged about one bat death per year in the period analyzed, “this strongly indicates that the NPM HCP estimate that it will have 1.7-2.5 bat takes per year is reasonable,” the board wrote.

Cut-In Speeds

Despite Izu’s arguments that the HCP should require a cut-in speed (the speed at which the turbines start to turn) of 6.5 meters per second, rather than the 5 m/s recommended by the ESRC, the board found that the studies she relied on are inconclusive as to whether the higher cut-in speed is any better.

But even if it were, the board noted that NPM’s Cutbirth testified during the hearing that generating electricity only when winds are blowing at 6.5 m/s and higher “could potentially put us in a situation where we’re not meeting our [HECO power contract] production requirements.”

“Lost power output is not just an economic issue for the applicant. There is also a cost to the public: it reduces the amount of renewable energy generated,” the board added.

What’s more, the Ko`olau bat study showed that bats were more likely to be present, at least at Kawailoa, when mean wind speeds were less than 4.6 m/s, and about 80 percent of bat observations occurred when mean wind speeds were less than 5 m/s, the board noted.

“To require LWSC [low wind-speed curtailment] at 6.5 m/s at the outset of operations, rather than as a part of adaptive management, is not necessary to minimize and mitigate the impacts of the take of ope`ape`a to the greatest extent practicable,” the board concluded.


To make up for all the expected bat deaths, the HCP commits to various habitat management activities at Poamoho ridge, such as fencing and ungulate and invasive weed removal. For a take level of 34 bats (Tier 1), NPM must pay $1.758 million, whether or not it takes all the bats allowed. If it looks like the facility is going to kill more than 34 bats, Tier 2 mitigation projects are triggered, and the company must pay an additional $894,000 for them.

Because ultraviolet and acoustic deterrent technologies aren’t yet proven effective, they — and research into them — can’t be considered as part of a mitigation plan under the Endangered Species Act. Even so, the board found that it had the authority to require such research and implementation “if they are shown to be effective, in addition to the mitigation currently required.”

The board then required NPM to contribute $100,000 toward research into deterrence and to implement it — after consultation with the ESRC — if it proves effective and commercially viable.

“The resulting research may also utilize other funding sources. The research project or projects shall be approved by DOFAW and results shall be made publicly available,” the board wrote.

Final Vote

The board members who voted in favor included chair Suzanne Case, Chris Yuen, Tommy Oi, Jimmy Gomes, and Sam Gon. After oral arguments in January, KNSC filed a motion seeking Gon’s recusal because he was an ESRC member when it recommended Land Board approval. The board ultimately decided to keep him in the loop.

Board member Keone Downing dissented and member Stanley Roehrig recused himself for having inadvertently discussed the case with a state legislator.

“The project should stabilize electricity rates and create new jobs. The project will spend up to $4.6 million dollars to assure there will be no negative impacts to Hawai’i’s environment and native and protected species,” the DLNR stated in a press release announcing the board’s decision. The $4.6 million covers mitigation for the incidental take of bats, the Hawaiian short-eared owl, and several species of waterbirds, including the endangered nene, coot, and moorhen.

— Teresa Dawson

For Further Reading

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