Wednesday, November 22, 2006

$402m Tidal Energy Plant For New Zealand



New Zealand’s Northern Advocate reports that a US $402 million (NZ $600m) proposal to generate electricity with 200 tidal-powered turbines submerged at the entrance to the Kaipara Harbour could get under way next year. The harbour is one of the largest in the world. It’s a broad shallow harbour covering an area of over three hundred square miles and has more than two thousand miles of shoreline. It has a two and a half mile wide entrance to the Tasman Sea halfway along its length.

Although officially called a harbour, the Kaipara is rarely used for shipping, owing to the treacherous tides and bars at its mouth. For this reason, no large settlements lie close to its shores, although small communities dot its coastline.



Crest Energy has applied to the Northland Regional Council for resource consent to set the 22m-tall turbines on the seafloor along about 8km of the 30m deep main channel at the harbour entrance.

The tidal energy is expected to get the turbines generating 200 megawatts of power - enough for 250,000 homes. The turbines, shielded from fish, would sit on heavy concrete pylons and be at least 5m from the surface at low tide. Leisure craft and barges could pass over them, but would be restricted from anchoring in the turbine area.

Two 30km-long cables 125mm in diameter would feed electricity into the national grid.

Crest Energy claims the size and commercial scale of the Kaipara project would make it the largest of its kind in the world.

If the project gets the green light, possibly around the middle of next year, the company plans to raise about $50 million to begin building turbines.

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11 Comments:

Anonymous Anonymous said...

New zealand is an alternative energy example.Everyday I read new green project . To compare France with Kiwis, we are late. NZ took the lead!
Even if we have to produce green, French Politics are not hurry!
what a shame.......

9:53 am, November 23, 2006  
Anonymous Anonymous said...

more countries to step up and under take projects like this. its only through research and practical applications that we can further develop and increase efficiences to make theses overly productive worldwide.

kudos to NZ and crest energy

12:47 pm, November 27, 2006  
Anonymous Margaret Butterworth said...

Here is a new project from Australia:

Ord River Tidal Power Proposal

Abundant cheap and green energy will be available in the Kimberley if the Ord River Tidal Power Project goes ahead. The promise of sustainable renewable energy in the region comes at an opportune moment as the debate about global warning intensifies.

On Monday, 13 November, Tidal Energy Australia (TEA) held a public meeting at the All Seasons Hotel to describe the proposed Tidal Power Project on the lower part of the Ord River. A similar meeting was held at the Wyndham Town Hotel on Wednesday, 15 November.

The meetings were held as part of the Environmental Protection Authority’s request for TEA to inform interested parties of the potential impact of the project and to receive their comments and concerns. This has to be done prior to the final report for public comment.

TEA’s consultants, Maunsell AECOM gave a detailed Powerpoint presentation supplemented with wall diagrams, maps and photographs. Many questions about the environmental impact were answered by Maunsells. The areas of concern, which will require further fieldwork and investigation relate to sedimentation, preservation of mangroves, impact on aquatic animals and heritage sites.

John Lewis and Brian Rourke, as Directors of TEA and the design engineers for the project, described the technical aspects of the proposal. A barrage site has been selected adjoining Limpet Island on the Lower Ord River, 10 k from Cambridge Gulf. This site has rocky abutments, good foundations and a natural bypass channel where the turbines and gates can be built “in the dry”, while the main rockfill embankment is being built.

The proposed power installation is 40 MW, but the site is big enough to accommodate 180 MW eventually. Tidal power is intermittent, and the scheme uses only the outgoing tide to turn the generators. This means that continuous power supply cannot be maintained 24 hours a day without a backup system. This problem will be solved by pumped storage at 100 m elevation in the nearby hills, whereby excess power is used to fill a pump storage dam from which water is discharged when needed. The same turbine machines will then generate power from this water. All the tidal plant has a life of up to 100 years and needs very little maintenance.

The project includes a high tension transmission line direct to the Argyle Diamond Mine, and will be built alongside the Great Northern Highway, with cross connectors to supply domestic power to Wyndham, Kununurra and many Aboriginal Communities. The latter depend upon expensive diesel generators for their power supply, which is approximately three times the cost of tidal energy.

The estimated cost of the project is currently $250 million, of which 70% will be borrowed funds in the form of long term loans and infrastructure bonds. The estimated selling price of power will be 13 cents kwh, which will not increase over time, provided increased demand can be secured at 3.6% p.a. In this respect the success of the Ord River Stage 2 Irrigation will be helpful but not essential for the project getting started.

The environmental process will take 12 months to complete, during which time design, costings, tender pricing, power purchase agreements and funding will be completed. Construction will take 18 to 24 months, depending on availability of contractors and equipment.

TEA said that if approval can be obtained for the Ord River Tidal Project it will be a lead for more projects in the Kimberley which require a cheap power supply. In particular, should the zinc mines be reopened at Fitzroy Crossing, a zinc refinery could be built at Derby. The Doctors Creek Tidal Energy proposal at Derby might then be revived.

12:23 am, December 01, 2006  
Anonymous tom_squick said...

Kewel

5:46 am, January 24, 2007  
Anonymous Anonymous said...

I just started reading about Blue energy (from http://www.yourgreendream.com/articles_blueenergy.php). With all their fresh water they should but in some blue energy plants as well.

8:24 pm, January 30, 2007  
Blogger Christopher said...

I was very excited when I picked up on tidal and perpetual wave energy for generating electricity - I posted some links at my blog http://www.creativeexpression.org/wordpress

And I agree that more countries should step up with this source of energy - I can understand practical bio-fuel ideas (something that doesn't illogically approach that concept with ehtanol/corn???) but here's something that makes so much more sense - the oceans are in infinite perpetual motion - this is a source of infinite energy --- when will more voices help the popular and mainstream media pick up on this concept.

1:22 pm, July 06, 2007  
Blogger saiprasanth said...

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2:31 am, July 11, 2007  
Anonymous robbrian said...

Thursday, December 13, 2007
Here's an estimate of what is potentially possible with just 1% of the ocean's energy.

Wave Energy Potential on the U.S. Outer Continental Shelf¹

The total annual average wave energy off the U.S. coastlines (including Alaska and
Hawaii), calculated at a water depth of 60 m has been estimated (Bedard et al. 2005) at
2,100 Terawatt-hours (TWh) (2,100--10 to the twelth Wh).2

Estimates of the worldwide economically recoverable wave energy resource are in the
range of 140 to 750 TWh/yr for existing wave-capturing technologies that have become fully mature (ETNWG 2003). With projected long-term technical improvements, this could be
increased by a factor of 2 to 3 (Thorpe 1999). The fraction of the total wave power that is
economically recoverable in U.S. offshore regions has not been estimated, but is significant even if only a small fraction of the 2,100 TWh/yr available is captured.

(Currently, approximately 11,200 TWh/yr of primary energy is required to meet total U.S. electrical demand.) WEC devices have the greatest potential for applications at islands such as Hawaii because of the combination of the relatively high ratio of available shoreline per unit energy requirement, availability of greater unit wave energies due to trade winds, and the relatively high costs of other local energy sources.

(Just think if we could harness the ocean in the form of a series of waterfall stations where water is either lifted into a catch basin and flows into penstocks, or arrives at the funnel as would a natural waterfall and then into the penstocks with their turbines, we could eliminate carbon dioxide emission almost overnight. Just a little imagination and a great deal of courage could get us there before we begin mass production of oxygen and gas masks.)

_______________________________
1. Technology White Paper on Wave Energy Potential on the U.S. Outer Continental Shelf, Minerals Management Service, Renewable Energy and Alternate Use Program, U.S. Department of the Interior 2. This estimate was made at a specified water depth of 60 m (irrespective of the distance from the shore at which that depth occurs) in order to allow comparisons of wave energies between coastal areas and to eliminate the possible, but unpredictable loss of energy of the wave through its interactions with the sea bottom (scouring) at shallower depths. Typical wave energy in U.S. offshore regions ranges from 2 to 6 kW/m in the mid-Atlantic, 12 to 22 kW/m in regions such as Hawaii with trade winds, and 36 to 72 kW/m in northwestern U.S. coastal areas near Washington and Oregon.

6:15 pm, January 12, 2008  
Anonymous robbrian said...

Thursday, October 25, 2007
Water everywhere and we're still afraid to harness it.
What if instead of building more dams on rivers and streams to generate electricity, we build a 2 to 3 mile long, 800ft deep, 350ft wide, ultra-modified dam in the Atlantic ocean about 5 miles beyond the three mile limit, off the coast of Norfolk, Virginia?

Picture the Grand Coulee Dam, which since 1941, helped to reshape the Northwest with cheap electricity, it generates 6.5 x 109 watts..= 6,500 megawatts..= 6.5 million kilowatts. It is also the largest concrete structure ever built.

US households use on average about 2 kilowatts of electricity, so the Grand Coulee Dam can power 3.25 million such homes.

Currently, approximately 11,200 Tera Watt hrs/yr of primary energy is required to meet total U.S. electrical demand. An ocean waterfall dam of the magnitude mentioned above would generate 15 to 20 times that amount and also replace energy created by natural gas, coal, wind, and solar.

So let's design a steel and concrete dam, float it out to sea, hook up power lines and use existing distribution hubs to electrify America. This would not be a Wave Dragon system or other wave energy device. Simply picture a waterfall like the Coulee Dam. It could be floated into place and anchored like an oil rigs components. Security for the site and sea life would be needed.

We send massive objects into space. We met the challenge of JFK's dream to go to the moon. Why can't we meet this type of challenge to save the planet from carbon emissions.



Why can't this be done? What are the significant technical constraints? There will be powerful interests in opposition to the effective use of ocean energy since it could replace profits gleaned by the Fossil Fuel Freaks, from raping the land and earths' inner fluids.



In the absence of freedom there is no creativity, in the absence of creativity there is no progress, in the absence of progress there is only stagnation.

2:38 pm, January 13, 2008  
Anonymous Anonymous said...

New Zealand is a great place for there to use alternative this plan. But how much is this going to benefit New Zealand? Would it benefit a place like Hawaii even more? Wouldn't this also get in the way of boats or other water craft? Does this tidal energy plant create a lot of energy and how much? You should look at my blog. www.ourend.blogspot.com

12:30 pm, May 23, 2008  
Anonymous John Wanoa said...

The Kaipara Harbor is the best guaranteed source of In-stream Tidal Energy that has a fixed volume column of water tonnage moving in and out of the Harbor every day from 900 square kilometers of water and about 2 billion cubic meters of water up to 50 meters thick in the deepest canyons so if you were to capture at least 30% of that In-Stream Energy you will be pretty well off with a heavy giant dynamometer Its the Turbine that matters the most the bigger blade area the better You can see a picture of it at flickr.com./photos/platinumtidalenergyelectricnz and find out how it works and you can comment on its concept Something must work somewhere sometime someplace somehow hydraulically possible probable

6:55 pm, July 19, 2008  

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