Editing Ocean thermal energy conversion (section)

=== Open ===
[[File:Otec Open Diagram in English.JPG|thumb|Diagram of an open cycle OTEC plant|220x220px]]

Open-cycle OTEC uses warm surface water directly to make electricity. The warm seawater is first pumped into a low-pressure container, which causes it to boil. In some schemes, the expanding [[vapor]] drives a low-pressure turbine attached to an [[electrical generator]]. The vapor, which has left its [[salt]] and other contaminants in the low-pressure container, is pure fresh water. It is condensed into a liquid by exposure to cold temperatures from deep-ocean water.  This method produces [[desalinization|desalinized]] fresh water, suitable for [[drinking water]], [[irrigation]] or [[aquaculture]].<ref name="vega05">{{cite web|url=http://www.otecnews.org/articles/vega/05_open_cycle.html|title=Open Cycle OTEC|last=Vega|first=L.A.|year=1999|website=OTEC News|publisher=The GreenOcean Project|access-date=4 February 2011|archive-url=https://web.archive.org/web/20081207045655/http://www.otecnews.org/articles/vega/05_open_cycle.html|archive-date=7 December 2008|url-status=dead}}</ref>

In other schemes, the rising vapor is used in a [[gas lift]] technique of lifting water to significant heights.  Depending on the embodiment, such [[mist lift|vapor lift]] pump techniques generate power from a [[water turbine|hydroelectric turbine]] either before or after the pump is used.<ref name=jsee>{{cite journal |journal=Journal of Solar Energy Engineering |last1=Lee |first1=C.K.B. |last2=Ridgway |first2=Stuart |title=Vapor/Droplet Coupling and the Mist Flow (OTEC) Cycle |volume=105 |issue=2 |pages=181 |date=May 1983 |url=http://library.greenocean.org/oteclibrary/otecdesigns/mistliftotec/vapor_mistlift_otec.pdf |bibcode=1983ATJSE.105..181L |doi=10.1115/1.3266363 |access-date=2012-06-02 |archive-date=2008-11-22 |archive-url=https://web.archive.org/web/20081122005914/http://library.greenocean.org/oteclibrary/otecdesigns/mistliftotec/vapor_mistlift_otec.pdf |url-status=dead }}</ref>

In 1984, the ''Solar Energy Research Institute'' (now known as the [[National Renewable Energy Laboratory]]) developed a vertical-spout evaporator to convert warm seawater into low-pressure steam for open-cycle plants. Conversion efficiencies were as high as 97% for seawater-to-steam conversion (overall steam production would only be a few percent of the incoming water). In May 1993, an open-cycle OTEC plant at Keahole Point, Hawaii, produced close to 80&nbsp;[[kW]] of electricity during a net power-producing experiment.<ref name=nrel-otec-achievements>{{cite web | title = Achievements in OTEC Technology | publisher = [[National Renewable Energy Laboratory]] | url = http://www.nrel.gov/otec/achievements.html}}</ref> This broke the record of 40&nbsp;kW set by a Japanese system in 1982.<ref name=nrel-otec-achievements/>