New Bathymetry Data Viewer from NOAA

NOAA has published a new tool to discover the Earth's ocean floor. It includes a lot of information about the sea floor and coasts, including deep canyons, ripples, landslides and likely fish habitat.

For those who sail in the coast of USA, this map has an aditional use because it includes the latest high-resolution bathymetric (sea bottom) data collected by NOAA’s Office of Coast Survey primarily to support nautical charting.

Check the Bathymetry Data Viewer

It has to be said the ease to navigate on the map using a “color-shaded relief” technique to depict bathymetric data and derived maps and models. Also you can select different basemaps and decide to visualize different options by layers.

Complete Press Release from NOAA.

[Other map viewers and resources from NOAA: Satellite Fire Detections, US Bathymetric and Fishing Maps, Geophysical Surveys, Hazards (Tsunamis, Earthquakes, Volcanoes), Thermal Springs in the United States, Marine Geology, Multibeam Bathymetric Data, NOAA Observing Systems Architecture(NOSA), NOS Hydrographic Survey Data, Index to Marine & Lacustrine Geological Samples]

Perpetual Ocean

Brilliant video showing ocean surface currents around the world during the period from June 2005 to December 2007.

httpv://youtu.be/xusdWPuWAoU

Further details: click

credit: NASA/Goddard Space Flight Center Scientific Visualization Studio

Gulf Stream from Wikipedia:

The Gulf Stream transports about 1.4 petawatts of heat, equivalent to 100 times the world energy demand,^[35] and research into different ways to tap this power is being undertaken.

One idea, which would supply the equivalent power of several nuclear power plants, would deploy a field of underwater turbines placed 300 meters (980 ft) under the center of the core of the Gulf Stream.^[36] Ocean thermal energy could also be harnessed to produce electricity utilizing the temperature difference between cold deep water and warm surface water.^[37]

Tidal power potential in USA

Recently I have written about the wave & tidal potential resource in UK. It's time to show a new mapping tool for the tidal power potential in USA.

This interactive and web-based GIS system has been created by the Georgia Tech University based on a database-driven mapping tool. You can check their "Assessment of Energy Production Potential from Tidal Streams in the United States"

Check the tidal power potential map in USA

This group from GTU has pointed several clues about tidal energy:

• It can be harnessed wherever there is moving water in significant volumes.


• Tidal stream is deterministic and and the energy production can be forecasted accuratly.


• This predictibility eases the installation, operation and maintenance.


• There are a lot of hot spots: Knik Arm, AK; Tacoma Narrows, WA; Golden Gate, CA; Muskeget Channel, MA; Western Passage, ME, Puget Sound, New York, Connecticut, Cook Inlet, Southeast Alaska, and the Aleutian Islands among others.


• Besides large scale power production, it can be useful as local and reliable energy source for remote and dispersed coastal communities and islands.

Criterias to be taken into account when you are involved in the process of selection of location:

1. Tidal current velocity: the speed and volume of water passing through the site in space and time.


2. Site characteristics:  bathymetry, water depth, geology of the seabed and environmental impacts will determine the deployment method needed and the cost of installation.


3. Electrical grid connection: the seafloor cable distance from the proposed site to a grid access point will help determine the viability of an installation.

UK has no doubts they should develop this industry in order to become leading exporter of wave and tidal power. As the team behind the map has written: "Tidal energy is one of the fastest growing emerging technologies in the renewable sector and is set to make a major contribution to carbon free energy generation."

What will USA do with this tidal potential?

Tidal resource in UK

Yesterday we published "wave resource in UK" so now it's the chance for tidal power.

Former DTI [currently DECC] estimated an available huge potential of 3000GW of tidal energy but, unfortunately, less than 3% is located in areas suitable for power generation. There are a lot of factors and inputs to be considered in the estimation of the tidal current potential as it is very site depending [seabed, bathymetrics, estuaries, etc.]

Note: There is a great paper from Stephen Salter: "Correcting the Under-estimate of the Tidal-Stream Resource of the Pentland Firth"

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  online interactive webGIS version of the UK Marine Renewable Energy Resources Atlas

  
  


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  Tide resource map

  
  

In 2001, a list with 42 sites around the UK suitable for tidal stream generation was launched and just the ten most promising tidal stream sites could offer a potential of 36 TWh/y, which means at least 34% of the UK's electricity demand.



Tidal power has the distinct advantage of being highly predictable compared with some other forms of renewable energy. The regularity of the tides, along with the huge energy potential, therefore helps to make tidal energy development an attractive resource option.

Image: Average Annual Tidal Power Crown ©2004

Wave resource in UK

Nowadays we are enjoying great news even coming from mass media about the huge potential and possibilities of wave and tidal sector. Guardian published early this year "UK could become leading exporter of wave and tidal power, say MPs" based on a report from Energy and Climate Change Committee calling on government to establish long term goals for marine energy to give guarantees and estability for further industrial developments.

WAVES

But, what is the real potential of waves? There are several studies trying to bring light to this issue. Independently of which one you read, all of them assure a potential far beyond our electrical energy consumption even highlighting that the wave global power potential is estimated to be around 8,000-80,000TWh/y (1-10TW), which is the same order of magnitude as world electrical energy consumption.

Evidently, not all the spots has the same potential. Best spots are found between 30-60 degrees latitude with a potential of 20-70 kW/m because the strong storms there. But for 30 degrees latitude there is a good choice when the waves come from regular wind blowing. Even with a less energy/potential, these places has an advantage over the first ones because the variability is reduced as well, which means generate electricity in a more regular basis and, maybe, reduce the mechanical efforts suffered by the devices.

UK

It is expected that marine energy could provide up to 27GW of capacity in the UK by 2050, much of which is expected to be deployed after 2020...but it will not become real if there isn't a real support from the Government today.

In 2008 the Department of Energy and Climate Change [DECC] published an online interactive webGIS version of the UK Marine Renewable Energy Resources Atlas with the clue of the highest potential spots.

The most conservative studies estimate the accesible potential around 50 TWh/y mainly situated off the northwest coast of Scotland and the seas of the southwest of England. This potential represents 12.4% of UK electricity generation, demanding the commercial development of the industry which both will lead to a cost decrease and will help in the path to become UK a leader in this area...but if there is a industrial development, the potential resource technically available could be much higher, as the wind industry development has demonstrated.

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  online interactive webGIS version of the UK Marine Renewable Energy Resources Atlas

  
  


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  Wave resource map

  
  

Image: Annual Mean Wave Height Crown ©2004

How do you like to do it: Horizontal or Vertical?

Tidal stream has a similar behaviour to wind as it is a fluid as well. So it has been relatively easy for engineering to transfer the concept of 3-bladed horizontal axis design to this new environment. Engineers argue that if it works with onshore and offshore air streams, being even the icon of clean energy and sustainability, why shouldn't it work with water streams?

It's pretty sure it will work. No doubt about engineering abilities on horizontal axis wind turbines. Yet we are talking about hydrodynamics and not aerodynamics,  the question should be: is this the best design we can achieve?

Recently I have read an interesting paper from Stephen Salter called "Are Nearly all Tidal Stream Turbines Designs Wrong?" which was presented during the Oxford Tidal Energy Workshop, held in Oxford during 29-30th March.

The aim of this paper is, in words of the author,  "to show that, despite its widespread popularity, the transfer from wind technology is wrong and that a cross-flow design with rotation about a vertical axis is better. "

3-bladed horizontal axis wind turbines are "universal" as everybody, including industry, investors, public, mass media and politicians assume it as the best choice in this area.

But if a company achieves a better design in terms of efficiency, cost reduction, installation and O&M in tidal/ocean streams using a vertical axis design [don'tforget it is a completely different environment] there will be a major question to answer:

* Will this company achieve a leadership position in the industry and get the confidence of the investors?

I guess this issue can be one of the main topics for the next as the technology is developing faster than expected and I hope to get a further understanding of the different possibilities of the designs.

Photo from Marine Current Resource and Technology Methodology