Makai Connects World’s Largest Ocean Thermal Plant to U.S. Grid

– August, 2015

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The chief engineer of Hawaii’s OTEC plant (Mike Eldred) and the chief engineer of the Okinawan OTEC plant (Shin Okamura) discuss plans to jointly build a 1MW with a group of Japan and U.S. organizations.
“One big difference with OTEC is that it is a firm power source; it allows us to generate electricity consistently… and in the evening hours when other renewable sources are not available, which really is the key to a 100% renewable future,” said Governor David Ige in his keynote address.
“I am really excited to see our friends from Japan and Okinawa here today, and excited about the opportunity to take this project to the next level in a way that will be mutually beneficial,” said Congresswoman Tulsi Gabbard.
RDML Muilenburg and Capt Tufts of NAVFAC Pacific and NAVFAC Hawaii
In addition to electricity for homes, OTEC can power the next generation of sustainable transportation. Here we make a start by charging a Tesla Model S using ocean thermal power.
Governor Ige flips the switch!
Ocean power ON!
Capt Tufts has a look at Makai’s Seawater Air Conditioning poster and demonstration
Governor David Ige and the First Lady, Mrs. Dawn Ige, greeting guests
Makai’s Dr. Eli Michael discusses his research and testing at the Marine Corrosion Laboratory with Captain Dean Tufts.
“I’d like to aloha Mayor Ota from Kumejima Island – Mayor Ota please stand,” said Mayor Kenoi, “Five years ago we signed the sister city agreement that is continually affirmed.”
Makai’s Mike Eldred gives a tour to dignitaries
“If we’re going to get 100% renewable in 2045, we’re going to have to have baseload, dispatchable power, and OTEC is one of the strong contenders.” said Dr. Rick Rocheleau of HNEI.
Guests gather at Makai’s newly renovated Ocean Energy Research Center at NELHA.
Governor Ige and Makai’s Duke Hartman pose for a photo in front of a Tesla Model S that received a charge from the OTEC plant
Kahu Kimo leads the blessing of the OTEC plant
“Navy believes in this,” said Dr. Rich Carlin of the Office of Naval Research, “The corrosion research lab is a key piece … when you see these heat exchangers, that was no simple task.”
Makai’s Director, Adam Wong, gave the opening speech.
Makai’s OTEC plant chief engineer Mike Eldred explains the plant to Governor Ige and the First Lady
Kahu Kimo leads the dignitaries in untying the maile lei
Dignitaries untie the maile lei
Congresswoman Tulsi Gabbard and Makai’s Duke Hartman in front of an ocean powered electric vehicle
To our knowledge, this is the first electric vehicle directly powered by OTEC!
Fair weather at the Makai Ocean Energy Research Center
Click the thumbnails below to view full-size graphics.


Makai Ocean Engineering celebrates the completion of the world’s largest operational Ocean Thermal Energy Conversion (OTEC) power plant with a dedication ceremony held on Friday, August 21, at 11:00 a.m. at the Natural Energy Laboratory of Hawaii Authority (NELHA).

Click the image above to view full gallery.

Makai’s OTEC power plant uses the temperature difference between the ocean’s cold deep water and warm surface water to generate clean, renewable electricity that is available 24 hours a day, 365 days a year. The NELHA-sited plant will generate 100 kilowatts of sustainable, continuous electricity—enough to power 120 Hawaii homes annually.

The breakthrough marks the first true closed-cycle OTEC plant to be connected to a U.S. electrical grid, and represents a major achievement for Hawaii, the United States, and marine renewable energy.

Distinguished officials gathered at NELHA to commemorate the occasion by “flipping the switch” to deliver OTEC power for the first time.


Governor David Ige
“Today marks the launch of the world’s largest operational ocean thermal power plant,” said Hawaii Governor David Ige. “This plant provides a much-needed test bed to commercialize ocean thermal energy conversion technology and bolster innovation, and it serves as a stepping stone to larger plants that will provide meaningful amounts of stable, clean power to Hawaii and other locations in Asia Pacific such as Okinawa in the near future.”

The research and development at the plant was funded by the Office of Naval Research (ONR) through the Hawaii Natural Energy Institute (HNEI), and the infrastructure was funded by Naval Facilities Engineering Command (NAVFAC). Accrued electricity revenues from this power plant will sustain further research and development of OTEC technology. A potential next phase for OTEC development at NELHA is being considered by an international consortium under the recently signed Okinawa-Hawaii clean energy agreement.


Remarks Regarding the OTEC Grid-Connection Ceremony


Congresswoman Tulsi Gabbard
“Hawaii’s abundant and diverse natural energy sources make our state an ideal location for innovation and growth in the renewable energy sector,” said Congresswoman Tulsi Gabbard. “Kona hosts the world’s largest operational ocean thermal energy conversion (OTEC) plant, which represents the potential that exists for a secure and energy independent future for Hawaii. This project displays what can happen when you have a successful public-private partnership that will serve as a model for clean energy technology worldwide.”

Mayor Billy Kenoi
“I’d like to aloha Mayor Ota from Kumejima Island – Mayor Ota please stand – and his entire delegation, including the university in Okinawa, and our partnership that we have where OTEC is real,” said Mayor Kenoi, “Five years ago we signed this sister city relationship that is continually affirmed… If we harness the best and brightest that we have, if we remain committed to our children and their future, if we continue to work together in a spirit of aloha, kindness, dignity and respect, we’ll realize what Adam [Wong] said: that we’ll get from 100 kilowatts to 1 megawatt, to 10 megawatts offshore, and ultimately to 100 megawatts.”

Senator Mazie Hirono
“In the pursuit of 100 percent renewable energy, Hawaii must consider all our energy options, including ocean thermal energy,” said Senator Mazie Hirono. “Ocean thermal energy conversion, or OTEC, could provide a stable supply of power from an abundant and clean source: the ocean’s heat. I am proud to announce that Hawaii is now home to the world’s largest operational OTEC plant that recently began feeding ocean-based power into the electrical grid at the Natural Energy Laboratory of Hawaii Authority in Kona. I applaud the work being done by the Office of Naval Research, Hawaii Natural Energy Institute, and Makai Ocean Engineering to develop this innovative technology for Hawaii’s energy future.”

Duke Hartman – Makai Ocean Engineering
“Makai is a world leader in the engineering of OTEC power plants, including the large marine pipelines, marine heat exchangers, and now the OTEC power cycle,” said Duke Hartman, Makai’s VP of Business Development. “We are thrilled to flip the switch on this important OTEC demonstration plant, which will deliver OTEC power to the grid and serve as a test bed to reduce the cost and improve the performance of OTEC technologies. Based on the lessons learned at this facility, we are working hand-in-hand with several of the world’s leading OTEC developers to design the next generation of commercial OTEC plants.”

Lockheed Martin
“Lockheed Martin and Makai have worked closely on OTEC projects for nearly 40 years, and this power plant in Hawaii is a significant milestone in our progress. These facilities are an asset to OTEC development and provide key performance testing for Lockheed Martin’s large-scale heat exchangers,” said Steve Klotz, engineering director at Lockheed Martin Energy. “As we develop larger scale OTEC plants, this facility will continue to serve as a valuable resource for validating and advancing our technology – and we look forward to our continued collaboration with Makai.”

About Makai Ocean Engineering, Inc.

Makai Ocean Engineering, Inc. is an innovative ocean engineering and design firm based in Hawaii, USA since 1973. Makai’s expertise includes submarine cable software and services, marine pipelines, Seawater Air Conditioning (SWAC), Ocean Thermal Energy Conversion (OTEC), autonomous underwater vehicles, marine corrosion, and general marine engineering and R&D. Makai is ISO9001:2008 certified, and applies strict quality control
methods to all of our engineering projects. Please visit for more information.


For more information, contact:
Duke J. Hartman, P.E.
Vice President, Business Development
+1 (808) 259-8871

Makai Ocean Engineering
Makai Research Pier
41-305 Kalanianaole Hwy
Waimanalo, Hawaii 96795 USA