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Measuring an Ocean's Currents for Energy

The ocean's waters are constantly flowing. Note only do tides cyclically flow, but ocean currents such as the Gulf Stream, the Florida Straits Current and the California Current flow in a constant and single direction. The amount of energy potential in the ocean's currents is tremendous. Because water is hundreds of times denser than air, flowing ocean water has nearly 10 times as much energy for the same surface area as wind. Just three-thousandths of the available energy from the Gulf Stream would supply enough electric energy to service all of Florida states the Big Bend Climate Action Team (BBCAT) in the report Ocean Current Power for Florida.

Things You'll Need

Calculator
Ocean current speed tables
Survey of ocean floor

Instructions

- 1
  
  The Gulf Stream has 21,000 times more energy than Niagara Falls. 1/1000 of it would supply Florida with 35 percent of its electrical needs.
  
  Delineate between the different types of currents that can yield exploitable energy available in the ocean you are studying. There are two main types of ocean currents -- marine currents and tidal currents. Tidal currents flow in and out on a cyclical basis, with half-day, daily and 14-day cycles, depending on the geography of the tides, flowing in one direction at the beginning of the cycle and reverse directions at the end of the cycle. Marine currents remain relatively constant in one direction, although their actual flow rate may be cyclical over a 10-year period. The Ocean Wave Energy Conversion study report from the University of Wisconsin-Madison states that the energy from oceans is concentrated, containing 15 to 20 times more energy per square meter than wind or solar. Wave energy is another form of energy that is currently being harvested from the ocean.
- 2
  Estimate the percentage of potential exploitable energy of the area of ocean that you are contains. For ocean currents, a velocity of at least 2 meters per second (4 knots) is required in order to make economic exploitation of current energy viable. The potential energy of all marine and tidal currents is about 5 TW (terawatts equal one-trillion watts) of energy, which is the equivalent of the entire world electric power consumption. The technology for converting ocean currents to energy is similar to that of hydroelectric power and uses turbines similar in appearance and structure to those of wind power turbines. Ocean current turbines need to be able to be secured to the ocean floor.
- 3
  
  The technology for exploiting the ocean's currents for energy is very similar to that used for hydraulic power plants and wind power farms.
  
  Determine the number of square kilometers that are suitable and available for underwater ocean current farms. In a similar way that above-ground wind farms are erected to harvest wind energy, underwater ocean current turbine farms can harvest energy en masse for transportable electricity.
- 4
  Multiply the total number of square kilometers by 37 turbines per square kilometer. If, for example, there are an estimated 10 square kilometers of suitable ocean available for a underwater current turbine power project, the area can contain up to 370 turbines.
- 5
  Multiply the number of turbines by 35 kilowatts of power, the amount of energy that can be generated from one turbine. 370 turbines would be capable of 12,950 kilowatts of power, enough to provide electricity for 74,000 homes.

Nature