Draft report calls for higher wind farm hoary bat allowance

Cutting speed of turbines has shown fewer deaths of the endangered species

Public comments are due Jan. 22 on a draft supplemental environmental impact statement for the Auwahi Wind Farm triggered by concern over escalating deaths of endangered Hawaiian hoary bats at Auwahi’s Ulupalakua site.

Under the proposed amendment, called for by the state Department of Land and Natural Resources, the wind farm would be allowed to increase its incidental take from 21 to 140 bats (129 direct and 11 indirect) through 2032. Previously, the proposed increased take was up to 197 bats.

But Auwahi Wind was able to reduce that from 197 to 140 bats after factoring in an operational reduction in the rate at which the wind turbines spin, said Sempra Energy spokeswoman Lisa Briggs. (Auwahi Wind is operated by Sempra U.S. Gas & Power. The Ulupalakua site has eight wind turbines generating as much as 21 megawatts per day.)

“Increased cut in speeds have shown positive results in reducing bat take on the Mainland,” Briggs said. “Sempra initiated this practice this year, and it allowed us to reduce the number of requested take.”

According to the supplemental environmental study, “this avoidance and minimization measure involves restricting turbine operation by feathering the turbine blades during periods of low wind speed in certain nighttime hours, as these conditions are associated with increased bat activity.”

The measure is an “operational protocol” that doesn’t involve physical modification of any facilities, the study says.

The Hawaiian hoary bat, known in Hawaiian as ‘ope’ape’a, is Hawaii’s only native land mammal, according to the U.S. Fish and Wildlife Service. Little research has been done on the bat’s habitat and population.

The nocturnal bat has a brown-and-gray coat and white-tinged ears. It preys on insects and is believed to roost among trees in areas near forests. In October 1970, the bat was listed as a federally endangered species.

DLNR determined that a supplemental environmental impact statement was needed, according to a memorandum prepared by wind farm consultant Tetra Tech.

The proposed revision for bat takes, or deaths, comes after an October 2016 DLNR report to the state Legislature on the status of permits for incidental takes of endangered species. That report showed Hawaii’s five major wind farms already had reached 146 of the 180 permitted bat fatalities as of the end of June 2016. That was barely five years after they had received permits of 20 years or more.

Auwahi Wind farm operations began in February 2012.

Send written comments to the state Department of Land and Natural Resources, Glenn Metzler, Division of Forestry and Wildlife, 1151 Punchbowl St., Room 325, Honolulu 96813, (email: Glenn.M.Metzler@hawaii.gov); Auwahi Wind Energy, 488 8th Ave., San Diego, Calif. 92101 (Marie VanZandt, mvanzandt@SempraGlobal.com); and Tetra Tech Inc., 1750 SW Harbor Way, Suite 400, Portland, Ore. 97201 (Alicia Oller, alicia.oller@tetratech.com).

* Brian Perry can be reached at bperry@mauinews.com.