Advocates of undersea cable say both Maui, Oahu would benefit
Prideful in the vein of “Maui No Ka Oi,” Valley Isle residents can be disdainful of that island up north. They scoff at Oahu’s traffic, crowds and concrete jungles.
Those planning Hawaii’s future power system believe Oahu might have something to offer Mauians other than business, shopping and a big city getaway – cheaper power and a more stable power grid.
The Public Utilities Commission has launched a study of the feasibility of a Maui-to-Oahu power interconnection. Plans call for laying a high-voltage cable 112 miles long and as much as 2,100 feet deep. Cost estimates for such a project have ranged from $600 million to $1 billion.
The commission has taken a neutral position on the proposal while its investigative proceeding to solicit information and public comments is underway.
If the commission decides the undersea power cable is in the public interest and the project advances, Maui and Oahu power consumers stand to benefit from a symbiotic relationship, according to Eric Gleason, president of NextEra Energy.
“What this is about is fundamentally helping Hawaii lessen its addiction on imported oil, and in the process, saving money, improving reliability and improving the environment,” Gleason said in an interview at The Maui News earlier this month. “The advantage of connecting the islands is (that) by having an interconnected grid you can share the most efficient resources, and you can improve reliability because each island can support the other island when needed.”
The Maui-Oahu power grid interconnect could be the first step toward integrating the Big Island’s power grid and its access to geothermal power, Gleason said.
“It’s creating a modern, integrated grid for Hawaii,” he said.
With its burgeoning wind and solar power alternatives, Maui could play a key role, he said.
“Maui potentially has much more and lower cost renewable resources than Oahu, but Oahu has today lower cost, more efficient fossil resources than Maui,” Gleason said. “By linking the two systems, Maui gets the benefit of the efficient fossil resource on Oahu, and Oahu gets the benefit of lower cost renewable resource on Maui.”
Valley Isle residents could see power bills drop, on average, from $100 to $170 per year over 40 years if the power transmission cable were built, he said.
“Regardless of the scenario, regardless of what kind of generation is added to the system, Maui customer bills would go down,” beginning in the first year of operation, Gleason predicted.
According to NextEra’s planning for the project, the undersea transmission cable could come on line as early as 2020.
NextEra, a company headquartered in Juno Beach, Fla., is one of two potential cable developers granted intervener status as part of the PUC’s investigative proceedings. The other is Hawaii Interisland Cable, a joint venture of Pattern Energy Group and Bio-Logical Capital LLC.
Hawaii Interisland Cable is proposing to develop a high-voltage, direct current converter and transmission system between Maui and Oahu, company official David Parquet said.
Such a system would be similar to Pattern Energy’s submarine Trans Bay Cable project in Northern California, he said. That development came on line in 2010.
“The Maui-Oahu high-voltage direct current system would contribute significantly to Hawaii’s sustainability by allowing the state to harness its abundant renewable energy resources and lower electric costs for ratepayers on Maui, Oahu and other islands,” Parquet said.
Based on a preliminary proposed route, NextEra’s plans call for a building a $600 million undersea cable that would come ashore at Maalaea Bay and Honolulu Harbor. The company would build a 2- to 2.5-story, 25,000-square-foot converter station near the Maalaea power plant, and using horizontal directional drilling, a cable would be drilled under the reef and go about a mile away from shore where it would rest on the bottom of the ocean, Gleason said.
According to NextEra, its preferred locations for a converter station on Maui are outside the tsunami inundation zone.
“For added protection from a tsunami threat, we will also consider further elevating the converter station site or moving further inland,” the company said.
Parquet said Hawaii Interisland Cable’s route for its planned cable “would be determined by Hawaii’s needs after consideration of many factors, including permitting, grid interconnection details and other requirements.”
“That said, the Iwilei substation and Koolau substation (on Oahu) as well as the Maalaea substation (on Maui) have received some level of analysis by stakeholders,” he said.
Gleason distinguished NextEra’s plans for an undersea power cable that would allow electricity to flow in both directions from the “Big Wind” projects proposed for Lanai and Molokai.
“Not all underwater cable projects are created equal,” he said. “What you’re talking about the Big Wind submarine cable project is what we call a gen tie, a generation tie – a tied-in generation resource from one island, Lanai or Molokai, to another, Oahu, and the power flows in one direction. What we’re talking about is a grid tie, which allows the power to flow in either direction depending on whatever’s most economic for the whole system and whatever will best improve reliability for the combined system.”
Technology available today doesn’t make it cost effective to have an electric system that is 100 percent dependent on renewable sources of power, Gleason said.
“So you need some combination of fossil resources, which can be dispatched and operate when you need them, together with renewable resources that are intermittent,” he said.
Now, with more efficient power generation available on Oahu, customers there pay approximately 5 cents less per kilowatt hour than Maui residents, he said.
NextEra’s director of Hawaii state affairs is former Wailuku resident Kay Fukunaga, a 2001 graduate of St. Anthony Junior-Senior High School. She earned her bachelor’s degree from Dartmouth College in 2005 and her master’s of business administration degree from Harvard Business School in 2010.
“This is a wonderful project, a unique opportunity to really transform Hawaii’s energy system,” she said. “I’m very proud to be working for NextEra Energy. This is a company that’s really a leader in its field, with a world-class team.”
* Brian Perry can be reached at firstname.lastname@example.org.