Environment

More funds for Hawaii's Ocean Thermal Energy Conversion plant

More funds for Hawaii's Ocean ...
An artist's impression of Lockheed Martin's Hawaii OTEC pilot plant
An artist's impression of Lockheed Martin's Hawaii OTEC pilot plant
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A diagram of the OTEC system
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A diagram of the OTEC system
An artist's impression of Lockheed Martin's Hawaii OTEC pilot plant
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An artist's impression of Lockheed Martin's Hawaii OTEC pilot plant
An artist's impression of Lockheed Martin's Hawaii OTEC pilot plan
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An artist's impression of Lockheed Martin's Hawaii OTEC pilot plan
An artist's impression of Lockheed Martin's Hawaii OTEC pilot plan
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An artist's impression of Lockheed Martin's Hawaii OTEC pilot plan
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An Ocean Thermal Energy Conversion (OTEC) pilot plant off the coast of Hawaii’s Big Island is now a step closer to reality. The U.S. Naval Facilities Engineering Command (NFEC) has just awarded Lockheed Martin a US$4.4 million contract modification to develop critical system components and designs for the plant – this amount is in addition to the $8.1 million contract the NFEC issued in 2009, as well as two grants totaling $1 million that Lockheed Martin received from the U.S. Department of Energy in 2008 and this March. Hopefully, this means the streets of Kona may someday be lit by electricity obtained from the temperature difference between warm and cold sea water.

OTEC centers around a closed system, which the sea water heats and cools. Here’s how it works...

A diagram of the OTEC system
A diagram of the OTEC system

Warm, sun-heated water from the top layer of the ocean passes through a heat exchanger, which causes a “carrier liquid” with a low boiling point (such as ammonia) to turn to steam. This steam travels up a pipe to a turbine, where it generates electricity. The steam then condenses back to liquid and travels down to another heat exchanger, this one cooling the liquid with cold seawater from lower depths. From there, a pump brings it back up to the first heat exchanger, and the system continues on ad infinitum.

The system is reportedly completely non-polluting, and is capable of providing power to warm-climate seaside communities 24 hours a day.

An artist's impression of Lockheed Martin's Hawaii OTEC pilot plan
An artist's impression of Lockheed Martin's Hawaii OTEC pilot plan

Lockheed Martin’s involvement with the field of OTEC dates back to the 70s, when it built a prototype plant that ran for three months.

The Hawaii pilot plant is expected to have a 10 megawatt capacity, and be operational by 2012 or 2013. It is hoped that its success will lead to commercial-sized plants generating 100 MW or better, by 2015. According to Lockheed Martin, such a plant could meet the electrical needs of a small city.

All images courtesy Lockheed Martin

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9 comments
martina2010
really great info, it motivates me to do something extra ordinary Nice post. I enjoy this post gorgeously with all of my friends. Really nice.thanks. Good information here. I really enjoy reading them every day. I\'ve learned a lot from them.
Adrian Akau
Kona is a good place for this type of technology; waters are calm most of the year. The sides of all the islands facing northwest would be fine for wave energy extraction since the majority of waves from storms comes from the northwest. The eastern sides usually have strong currents and underwater turbines could be used on those sides.
Facebook User
A small OTEC barge was floated off the coast of Hawaii in the 80\'s, maybe as far back as the late 1970\'s. I\'d heard it had been concluded the amount of energy to be extracted from ocean temperature differences was too low to be worth the bother.
tsvieps
Once again, an article about a \"promising\" new energy source with no info about the most important factor--cost efficiency. You need some real reporters who can do more than republish a press release.
Plasma Junkie
Ocean floor temp is around 4C or 277K. Say surface temp is 27C (300k). That means that the maximum thermodynamic efficiency of the cycle is 1-277/300=7.6%. OK, your fuel is free but you\'re going to have to circulate a LOT of water to get meaningful amounts of power and I suspect your pumping and conversion losses will make this impractical or require truly massive installations.
BigCat
Actually, at Kona you don\'t need something so elaborate. There\'s a live volcano nearby, so use a steam turbine based on geothermal power. They\'ve been doing it for a long time in Iceland.
tsvieps
Plasma Junkie nailed the physics. There is no way around this. How about getting your reporters to ask follow up questions of the folks that issue you information if your reporters are not able to do some due diligence ahead of the first publication here.
EGM
tsvieps: the costs are given ... $4.4M $8.1M $1M = $13.5M It\'ll produce: 10 MW x 24 x 365 = 87,600 MW hr/yr At $0.10/kWhr or $100/MWhr, annual revenues are $8,760,000 or $8.76M/yr That means a payback of less than 2 years ... pretty darn good! Apparently Hawaii rates are much higher than $0.10/kWhr for even faster payback!!!
CliffG
tsvleps, the $4.4M is \"to develop critical system components and designs for the plant.\" They are still at the design stage. This is on top of $10.1M already spent. LM is not known for low-cost gadgetry. It will be another $50M before anything ever produces a single kW and likely $250M before it reaches its design output of 10MW. If you look at image one from the photo gallery, you will see we have no business investing tax-payer money in OTEC - the resource is in the wrong place.