America’s First Tidal Power Plant

choi

(1) Press release: Maine Deploys First US Commercial, Grid-Connected Tidal Energy Project. US Department of Energy (DOE), July 24, 2012
http://www.doe.gov/articles/main ... idal-energy-project
("Today, Energy Secretary Steven Chu recognized the nation’s first commercial, grid-connected tidal energy project off the coast of Eastport, Maine. Leveraging a $10 million investment from the Energy Department, Ocean Renewable Power Company (ORPC) will deploy its first commercial tidal energy device into Cobscook Bay this summer")

Note:
(a) Eastport, Maine
http://en.wikipedia.org/wiki/Eastport,_Maine
(a small city (consisting entirely of islands); The population was 1,331 at the 2010 census; Eastport is the easternmost city in the United States (although the nearby town of Lubec is the easternmost municipality); The principal island is Moose Island, "which lies between Cobscook Bay to the west and Passamaquoddy Bay to the east")

* Maps. Cobscook Bay Area Chamber of Commerce, undated.
http://cobscookbay.com/maps.htm

(b) Ocean Renewable Power Company, LLC (ORPC)
http://www.orpc.co/
(headquarters Portland, Maine)
(i) The pulldown menu in the tag "ORPC Power Systems" at the top horizontal bar brings one to "Turbine Generator Unit":
"ORPC power systems are designed around our proprietary Turbine Generator Unit, or TGU. Our TGU works on the same principle as a wind turbine, with rotating foils that power a central permanent magnet generator. But because we install it underwater, and water is more than 800 times denser than air, our TGUs provide significantly more power than wind turbines at relatively low water current speeds. Built primarily with composite materials, they resist corrosion in fresh and salt water alike. As gearless units, they require no lubricants
(ii) ORPC's TidGen™ Tidal Energy Power System. YouTube.com, published on Jul 16, 2012 by oceanrenewablepower.
http://www.youtube.com/watch?v=t ... =2&feature=plcp
(an animation)
(iii) A single turbine is pretty huge. See the photograph in
ORP Hosts Dedication Ceremony for First Phase of Cobscook Bay Project. SeaDiscovery.com, July 24, 2012.
http://www.seadiscovery.com/mtStories.aspx?ShowStory=106998
(c) This turbine is the second generation, whereas world's first tidal generator (see (3) below) is of windmill type.
Alok Jha, Second Generation Tidal Turbines Promise Cheaper Power; 'Lawnmower' design turbines are more robust and larger than conventional windmill type. Guardian, Sept 4, 2008
http://www.guardian.co.uk/enviro ... wer.renewableenergy
("At full size, a Transverse Horizontal Axis Water Turbine (Thawt) rotor [designed by Oxford University] would be 10m in diameter and 60m long")

(2)
(a) The press release referred to
Tapping into Wave and Tidal Ocean Power: 15% Water Power by 2030. DOE, Jan 27, 2012.
http://energy.gov/articles/tappi ... 15-water-power-2030
("The United States uses about 4,000 terawatt hours (TWh) of electricity per year. The reports find that the nation’s waves and tides could potentially produce up to 1,420 TWh annually. * * * The West Coast, including Alaska and Hawaii, has especially high potential for wave energy development while significant opportunities also exist along the East Coast")

, which in turn pointed to "two recently released resource assessments":
(b) Assessment of Energy Production Potential from Tidal Streams in the United States. Georgia Tech Research Corp, June 29, 2011 (DOE grant award number: DE-FG36-08GO18174)
http://www1.eere.energy.gov/water/pdfs/1023527.pdf

Quote:

"The results of the regional assessment show that the state of Alaska (AK) contains the largest number of locations with considerably high kinetic power density, and is followed by, Maine (ME), Washington (WA), Oregon (OR), California (CA), New Hampshire (NH), Massachusetts (MA), New York (NY), New Jersey (NJ), North and South Carolina (NC, SC), Georgia (GA), and Florida (FL). The average tidal stream power density at some of these locations can be larger than 8 kW/m2 with surface areas on the order of few hundred kilometers squared, and depths larger than 100 meters. The Cook Inlet in AK is found to have a substantially large tidal stream power density sustained over a very large area." page 3

"Tidal streams are high velocity sea currents created by periodic horizontal movement of the tides, often magnified by local topographical features such as headlands, inlets to inland lagoons, and straits. As tides ebb and flow, currents are often generated in coastal waters." page 4

(c) Note:
(i) tera-
http://en.wikipedia.org/wiki/Tera-
(ii) Cook Inlet
http://en.wikipedia.org/wiki/Cook_Inlet
("Other Europeans to visit Cook Inlet include the 1778 expedition of James Cook * * * The inlet was named after Cook in 1794 by George Vancouver [1757-1798; English], who had served under Cook in 1778")


(3) SeaGen
http://en.wikipedia.org/wiki/SeaGen
(world's first large scale commercial tidal stream generator; installed in Strangford Narrows between Strangford and Portaferry in Northern Ireland in April 2008

Note:
(a) Strangford Lough
http://en.wikipedia.org/wiki/Strangford_Lough
(b) lough (n; Middle English, of Celtic origin; akin to Old Irish loch lake; akin to Latin lacus lake):
"1 chiefly Irish: LAKE
2 chiefly Irish: a bay or inlet of the sea"
http://www.merriam-webster.com/dictionary/lough

(4) Take notice a tide is different from a marine current. Take Taiwan as an example.

Marine Energy (a page in Renewable Energy). Industrial Technology Research Institute, Taiwan, undated
http://www.re.org.tw/Eng/hydro_2.aspx

Quote:

"A. Marine current: The Black Current has the biggest potential for electricity generation.  It is about 200 -500 m thick, and about 100 -800 km wide. Its velocity is between 0.5 m/sec to 1 m/sec."

"B. Tidal: The biggest tide difference occurred in Kinman and Matsu off-shore islands. The tide difference is about 5 m at these places.  The average tide difference is only about 3.5 m at western coast of Taiwan.  This is below the economical tide difference of 6~8 m.  Because the electricity generation cost is higher [in the outlying islands], it may be suitable to develop tidal energy in Kinman and Matsu off-shore islands.

Note:
(a) Kuroshio Current  黒潮
http://en.wikipedia.org/wiki/Kuroshio_current
(b) Taiwan strives, but has not produced a commercial tidal or maine generator.