World's Newest Form of Marine Renewable Energy Launched in Hawaii

It's called Ocean Thermal Energy Conversion, or OTEC, and the world's largest plant was dedicated in Hawaii on August 21. It produces renewable energy by using the temperature difference between the ocean's deep cold water and warm surface water.

2 minute read

August 31, 2015, 9:00 AM PDT

By Irvin Dawid


Emission-free energy is now being produced in Hawaii by Makai Ocean Engineering, thanks to funding by the Office of Naval Research through the Hawaii Natural Energy Institute," states Makai's news release. The $5 million, 105-kilowatt demonstration plant on the Big Island "only generates enough electricity to power 120 homes," writes Cole Mellino for EcoWatch. "But to date, it’s the largest such plant in the world."

Corrosion Facility

Credit: Makei Ocean Engineering

The company estimates that all of Hawaii’s electricity needs could be met by about 12 commercial-scale OTEC plants. They already have plans to construct a 1-megawatt facility in Japan.

“Anywhere tropical with deep water is ideal, especially if they import their fuel,” says Duke Hartman, vice president of business development at Makai.

While technically classified as a type "marine renewable energy," it's actually a form of solar energy, captured by the ocean and converted to electricity. "That’s beautiful because we can extract that energy 24/7 and use that power any time we want it, totally eliminating the need for an energy storage system,” states Hartman.

"Heat exchangers are really the key component to OTEC," states Hartman in this five-minute YouTube video as he point to the three pipes, standing on top of the plant.

Credit: Makei Ocean Engineering

"OTEC is a technology that the Navy has a significant interest for generating power at Naval bases around the world," states the naval research paper, "Understanding Predictability of the Ocean" [PDF]. "By using an [sic] Rankine engine cycle with fluorine gas cooled by deep ocean water and warmed by surface waters, turbines are used to generate electrical power that is sent back to shore."  [The video explains it in more detail.].

"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," according to the news release.

The biggest challenge remains will be funding. "We need a visionary investor to get us past the expensive pilot project into the large-scale commercial projects," states Hartman.

Wednesday, August 26, 2015 in EcoWatch

Sweeping view of Portland, Oregon with Mt. Hood in background against sunset sky.

Oregon Passes Exemption to Urban Growth Boundary

Cities have a one-time chance to acquire new land for development in a bid to increase housing supply and affordability.

March 12, 2024 - Housing Wire

Aerial view of green roofs with plants in Sydney, Australia.

Where Urban Design Is Headed in 2024

A forecast of likely trends in urban design and architecture.

March 10, 2024 - Daily Journal of Commerce

Cobblestone street with streetcar line, row of vintage streetlights on left, and colorful restaurant and shop awnings on right on River Street in Savannah, Georgia.

Savannah: A City of Planning Contrasts

From a human-scales, plaza-anchored grid to suburban sprawl, the oldest planned city in the United States has seen wildly different development patterns.

March 12, 2024 - Strong Towns

Aerial View of Chuckanut Drive and the Blanchard Bridge in the Skagit Valley.

Washington Tribes Receive Resilience Funding

The 28 grants support projects including relocation efforts as coastal communities face the growing impacts of climate change.

March 18 - The Seattle Times

Historic buildings in downtown Los Angeles with large "Pan American Lofts" sign on side of building.

Adaptive Reuse Bills Introduced in California Assembly

The legislation would expand eligibility for economic incentives and let cities loosen regulations to allow for more building conversions.

March 18 - Beverly Press

View from above of swan-shaped paddleboats with lights on around artesian fountain in Echo Park Lake with downtown Los Angeles skylien in background at twilight.

LA's Top Parks, Ranked

TimeOut just released its list of the top 26 parks in the L.A. area, which is home to some of the best green spaces around.

March 18 - TimeOut

News from HUD User

HUD's Office of Policy Development and Research

Call for Speakers

Mpact Transit + Community

New Updates on PD&R Edge

HUD's Office of Policy Development and Research

Urban Design for Planners 1: Software Tools

This six-course series explores essential urban design concepts using open source software and equips planners with the tools they need to participate fully in the urban design process.

Planning for Universal Design

Learn the tools for implementing Universal Design in planning regulations.