FutureStructure

Introducing the World’s Largest Ocean Thermal Energy Conversion Power Plant

This type of renewable energy has been shown as three times more stable than solar or wind power -- it is available 24 hours a day, 365 days a year.

by / August 21, 2015
Natural Energy Laboratory of Hawaii Authority, home of the world’s largest operational Ocean Thermal Energy Conversion power plant. Flickr/Nemo's Great Uncle

Stand back solar and wind power, there’s a new renewable energy in town. It’s called Ocean Thermal Energy Conversion (OTEC), and this week it takes a huge leap forward as Makai Ocean Engineering launches the world’s largest operational OTEC power plant at the Natural Energy Laboratory of Hawaii Authority (NELHA).

The power plant utilizes the ocean’s warm surface water and cold deep water to generate 100 kilowatts of renewable energy that is available 24 hours per day, 365 days per year. That translates to enough clean, sustainable energy to power approximately 120 homes.


Image via Makai Ocean Engineering

More specifically, in the closed-cycle system, there is a long, closed loop of pipeline filled with a fluid such as ammonia that never leaves the pipe. The ammonia continuously cycles around the loop, absorbing heat from the ocean and releasing it to the OTEC power plant, then returning as a cooled fluid to collect some more, according to Explain That Stuff

While OTEC technology has been around for a while, this is the first time it has been utilized on such a large scale. Since the low-variable temperatures of the tropics lend themselves so well to OTEC, Makai Ocean Engineering partnered with the Office of Naval Research to research and develop this power plant, based in Hawaii. As the U.S. Navy has proposed a goal to have 50 percent of its shore-based energy to be renewable by 2020, this power plant serves as a huge stepping-stone toward reaching that goal.

Makai Vice President of Development Duke Hartman notes that one of the biggest benefits of OTEC renewable energy is its stability, which has been shown as three times more stable than solar or wind power. “It is available 24 hours a day, 365 days a year. That is a big deal in terms of energy security and reliability, “ he says.

In addition to naval and government use, OTEC power plants also pose a huge opportunity for tropical communities, like Hawaii. In fact, the state of Hawaii is so confident in OTEC technology that it has set a goal to operate on 100 percent renewable energy by 2045. While it may seem like a lofty goal to some, Duke points out that it’s very achievable.

“Hawaii sees OTEC as a viable base load of a constant power source,” he says. “The power plants would be offshore, produce no emissions, and provide 100 percent of the power at a competitive rate. That adds up to a compelling case for OTEC.”

While OTEC technology resources do rely on specific geographical conditions (i.e. warm, tropical climates), the potential impact is still significant and could reach all areas near the coast, including the Caribbean, Mexico and even parts of Florida. What’s more, Makai has conducted research to explore the possibility of roving power plants that could potentially be connected with ships at sea or exported around the world.

Looking ahead, Makai hopes to continue developing larger OTEC power plants, with the overarching goal of completing a 100-megawatt plant. As Duke points out, each successful project will help to raise awareness about the effectiveness of OTEC power and will encourage more government agencies, organizations and businesses to invest in the technology.

“We believe the technology is already there,” Duke adds. “It just needs a commercial visionary and partner who can see the long-term vision of supplying megawatts and gigawatts of power and get us through this pilot plant.”

While there’s still progress to be made, the launch of the world’s largest OTEC power plant marks an important step for renewable energy and innovation. With state officials from Hawaii and other supporters present at the launch event, this week is cause for celebration, especially for the engineering team at Makai.

“It’s been a lot of work and a long culmination,” Duke says. ”We’re excited about this milestone and to flip the switch and kick it off.”

Julia McCandless Contributing Writer

Julia McCandless is a journalist passionate about finding the story and telling it well. She currently works as a freelance journalist and communications expert in Northern California, where she lives with her husband and son.