Small-scale wind turbines that don’t resemble the rotating fans seen on typical wind farms could start popping up around the state under an ambitious plan by a startup company.

A firm headed by an engineer from Japan recently secured a site on state land in Kakaako for testing its turbine system, which looks more like a slim water tower or drill rig.

Kanoa Winds Inc., a Delaware-based company led by Kaname Takeya, still needs other approvals to establish its planned research and demonstration project, but claims that its system is quiet, bird friendly and suitable for urban settings.

The turbines proposed by Kanoa are designed primarily to generate power for on-site residential, commercial and public use, as opposed to feeding electricity into the utility grid. Uses of the system Kanoa aims to roll out could include powering a home or business, electric vehicle charging stations, lights, pumping stations, cell towers and other things.

Board members of a state agency that owns the planned demonstration site, the Hawaii Community Development Authority, unanimously agreed at a July 3 meeting to negotiate a three-year land use agreement for the project that would require Kanoa to obtain permits to establish the turbine system for a proposed two-year test period.

The turbine for the test, according to Kanoa representatives, is based on technology that has been in commercial use in Japan for 18 years. The test site is roughly a single stall in a parking lot at the state’s Entrepreneurs Sandbox technology workspace facility adjacent to the University of Hawaii John A. Burns School of Medicine.

Kanoa’s planned test turbine would be 23 feet tall, and when spinning looks like two vertical cylinders in a metal frame.

Commercial versions of the same system can include larger turbines and more of them stacked vertically to create power generation capacities up to 10 kilowatts. The test model would be a 0.5-kilowatt unit capable of producing 10 to 25 kilowatt hours of electricity a day.

A typical residence on Oahu uses about 500 kilowatt hours a month, or about 17 kilowatt hours a day.

Kanoa’s long-term commercialization plan, if realized, would add to what utility companies refer to as distributed energy resources, or small systems like rooftop solar installed by electricity users.

It’s difficult to compare electrical generation between commercial versions of what Kanoa proposes and residential rooftop solar systems, the latter of which on Oahu have an average generation capacity of 7 kilowatts, according to Hawaiian Electric. Actual power output depends on the duration and variation of needed weather.

Still, Kanoa representatives see a lot of potential in their plan.

“We’re extremely excited to begin this renewable energy journey and introduce this technology into the United States, and specifically in Hawaii, in a collaborative effort with HCDA,” Robert Cundiff, a local business consultant and Kanoa advisory board member, told HCDA’s board during its recent meeting.

Mary Alice Evans, an HCDA board member who heads the Hawaii State Office of Planning and Sustainable Development, said during the meeting that small-scale wind turbines that spin on a vertical axis could be a more publicly acceptable contributor to achieving a state goal to derive 100% of electricity from renewable sources by 2045, compared with wind farms that use giant turbines with blades spinning on a horizontal axis and have drawn much public and political opposition.

“As we know, the 2045 electrical generation target goal depends on wind, but there’s a very strong lack of acceptance by communities to the (large) wind turbine approach, and I definitely want to see how this vertical tube approach tests out,” she said.

Eight utility-scale wind farms exist in Hawaii — three on Oahu, three on Maui and two on Hawaii island — that have production capacities ranging from 10.5 megawatts to 69 megawatts.

The most recent one, Na Pua Makani, developed in 2020 by AES Corp. in Kahuku, is a 24-megawatt farm with the capability to power about 16,000 homes, or about 2,000 homes for each one of its eight turbines that are 568 feet tall.

The AES Kahuku wind farm received regulatory approvals that included acceptance of an environmental impact statement, but the project drew heavy opposition largely from area community members over concerns that some turbine sites were too close to homes and schools and would produce harmful visual and acoustic effects on people.

About 200 protesters were arrested over actions that involved trying to stop turbine parts from being delivered to the project site.

There has also been opposition to wind farms locally over the number of endangered birds and Hawaiian hoary bats they kill.

Kanoa representatives said birds have nested without harm on top of some operating turbine systems in Japan, and that the Japan Falconiformes Center, an organization supporting conservation of wild raptors, has endorsed the technology the company aims to develop in Hawaii.

“We believe that the vertical coaxial wind turbine represents a sustainable wind capture within close proximity to both citizens, transportation and densely populated areas, opening up the opportunity for more wind power in more locations in a safe manner,” Jason Ho‘opai, another Kanoa advisory board member, told HCDA’s board.

Kanoa’s goal is to establish use of its turbines in Hawaii ahead of a broader expansion on the mainland. Ho‘opai said Hawaii was selected as a starting place because of strong prevailing winds and the state’s high dependence on fossil fuel for electricity.

Though Kanoa describes the technology of its system as revolutionary, it is not totally unique. Many kinds of vertical axis wind turbines exist worldwide, with small to large power generation capacities. There are also a few small-scale wind turbines with generation capacities up to 100 kilowatts operating in Hawaii, according to the Hawaii State Energy Office.

Cundiff said that Takeya, Kanoa’s CEO, helped develop the turbine system being used in Japan, and that the turbine slated for testing is a new, more efficient second-generation model.

Kanoa representatives believe their system is well suited for urban areas around the state in part because the system is quiet, can operate in low to very high wind speeds and is not dangerous to wildlife. The system also does not vibrate, and therefore, can be put on top of buildings, according to the company.

Ho‘opai told HCDA’s board that the system generates noise at or below 40 decibels, which he said approximates the sound level of people in a room talking. “It is very quiet,” he said.

According to Illinois-based noise control solution firm IAC Acoustics, 40 decibels is the lowest limit of urban ambient sound and is about as loud as bird calls or typical sound inside a library.

Unlike traditional wind farm turbines that disengage from operating when wind speeds reach around 50 mph, the system proposed by Kanoa can generate electricity in wind speeds ranging from 7 to 134 mph, according to the company.

Craig Nakamoto, HCDA executive director, said in a statement that he is encouraged by the turbine technology’s well-established use in densely populated parts of Japan.

“We are very excited to be collaborating with Kanoa Winds to test this technology’s small but mighty ability to harness the power of wind, for a new alternative to Hawaii’s clean energy future,” he said.