Five years after offshore wind energy burst onto the scene as an intriguing new candidate in Oahu’s future power generation mix, the idea continues to quietly gain momentum.

The federal government earlier this month published offshore block maps required to auction off the rights to lease a section of federal waters for offshore wind projects off Oahu.

Additionally, a fourth company has entered the competition for the right to build a floating wind farm, the only technology that would work in Hawaii’s relatively deep coastal waters.

Meanwhile, the world’s first floating offshore wind farm was activated off the coast of Scotland and is now generating 30 megawatts of power for onshore use.

The primary developer of Hywind Scotland is Statoil ASA, a multinational company from Norway with a subsidiary, Statoil Wind US LLC, that has announced its intention to compete for the right to create a working floating wind farm off Oahu.

State Rep. Chris Lee is now preparing a bill that welcomes offshore wind energy but seeks to establish ground rules and limitations so that they don’t harm cultural resources, communities and other sensitive areas.

“I support renewable technologies that lower costs to the ratepayer in the long run,” said Lee (D, Kailua-Lanikai-Waimanalo), chairman of the House Committee on Energy and Environmental Protection. “But we’ve got to let them know there are certain areas that are important to keep pristine and communities protected.”

Hawaii began eyeing offshore wind energy five years ago after then-Gov. Neil Abercrombie invited the federal government’s Bureau of Ocean Energy Management (BOEM) to establish a task force to explore requests for commercial and research seafloor leases and right-of-way grants for power cables in federal waters that begin 3 nautical miles offshore of Hawaii. The task force includes representatives of federal, state and local governments.

President Barack Obama would later lay claim to the effort as part of his Climate Action Plan to create American jobs, develop clean energy sources and cut carbon pollution.

BOEM issued a formal call for companies interested in developing an offshore wind project here, and multiple public meetings were conducted in 2016, with community members voicing concerns ranging from the impact to ocean views to the impact to fishing.

John Romero, BOEM spokesman, said the agency continues to evaluate the responses to its call and is trying to determine where potential offshore wind energy leases would be suitable off Oahu, which includes working with the Department of Defense to identify areas that would be compatible with military uses.

The drive to create an offshore wind farm that would send electricity ashore via undersea cables has so far survived changes of administration on both the federal and state levels.

The Oahu lease block maps appeared in the Federal Register on Jan. 5, the day after President Donald Trump unveiled his plan to open up America’s coastal waters to offshore oil and gas exploration.

While Hawaii and its coastal waters don’t harbor any oil or gas resources, they do have plenty of wind to harness. Previously described offshore projects suggest a potential of generating enough electricity to power 25 percent of the island.

Gov. David Ige said his administration remains committed to 100 percent renewable energy.

“Every type of renewable resource is up for discussion to help Hawaii reach its goal, and that includes offshore wind,” Ige said in a statement. “However, we are aware of concerns raised by Hawaii residents as we continue to work with BOEM.”

In 2016 two companies brought forward proposals. AW Hawaii Wind LLC, a subsidiary of Danish-­based Alpha Wind Energy, wants to build two projects: an Oahu South project, consisting of 51 floating wind turbines 17 miles south of Diamond Head, and a 51-turbine Oahu Northwest project 12 miles northwest of Kaena Point.

Oregon-based Progression Energy LLC proposes to bring 50 turbines to a site 15 miles off Oahu’s South Shore.

Statoil Wind US said it wants to use an area as large or larger than the areas designated by the two other companies.

A fourth company, as yet unnamed, is being reviewed by the BOEM to determine whether the company is legally, technically and financially qualified to participate in a future lease sale offshore Oahu, Romero said.

In the meantime, Hawaiian Electric Co. continues to assert its willingness to accept power from offshore sources but didn’t include them in a recent draft request for proposal for renewable-energy projects over the next five years.

But some say the state Public Utilities Commission should compel the utility to consider offshore wind sooner rather than later, in part to secure special federal tax credits set to expire.

“Offshore wind energy projects have the potential to play a particularly important role in Hawaii’s clean energy future,” Blue Planet Foundation’s Melissa Miyashiro said in a filing to the PUC.

Miyashiro added that such projects are more capital-intensive than onshore projects and, with more environmental review and approvals required, they will need a longer timeline for development.

Ted Peck, CEO of Holu Energy LLC and a Progression team member, said floating offshore wind technology is commercially viable now, and Progression proposes to use the same proven technology already under development in California, Japan, Korea, Taiwan, France, the United Kingdom and Portugal.

Peck, former head of the state Energy Office, said Hawaii’s biggest utility should offer a pathway for development over the next five years.

But Mark Glick, another former head of the state Energy Office, was more cautious. He said the utility has a lot to weigh in regard to offshore wind, including how to balance environmental, technical, cultural and economic concerns.

Ultimately, it’s got to make sense financially, he said.

“You don’t want to walk down a path that is not commercially viable,” said Glick, now a faculty member of the University of Hawaii’s Hawaii Natural Energy Institute.

“You can’t take this for granted,” Glick said. “There’s a lot of due diligence ahead, especially with a limited track record. This kind of utility-scale development requires more review.”