Energy From the Oceans - Current Power

Major currents are shaped by:

• Temperature differences (driven mostly by tilt of earth's axis)
• Prevailing wind patterns interacting with the surface waters (again driven mostly by tilt of earth's axis)
• the rotation of the earth the Coriolis Force
• shorelines of continental masses

The largest single current in the World is the Gulf Stream Current:

Tapping the Current for Energy:

• Gulf current has 1000 times the flow of the Mississippi River(!)
• It is 80-150 km wide and 800-1200 m deep.
• Current averages about 3 mph (but velocity varies a lot with depth - fastest velocities are at the surface)
• Density of water is higher as well
• Its always there - no intermittency problem no need for energy storage
• Build Turbines for underwater use
• Anchor a foundation to the ocean floor
• hundreds of miles long rigged with turbines
• cables on ocean floor to shore deliver the electricity

Some Specifics to estimate total yield:

• Ocean currents have approximately 830 times the energy density of moving air (i.e. wind).

• For a 2 m/sec current, the equivalent power density is 4 KW per square meter. (recall that a 10 m/sec wind produces 600 watts per square meter - now even though the density is 830 times larger, the power per unit area goes as the velocity³ so the net gain is only a factor of 6.5)

• Assume underwater array of 3 blade turbines with blade length of 2 meters. That means 50KW unit capacity but in principle the spacing between the turbines is small so can pack them tightly together.

• So we build a 1 km leg with turbines space by 4 meters. Each leg then has 250 units x 50 kw = 12.5 MW per km.

• Now lets build parallel legs over a 10 km wide section in the middle which each leg seperated by say 100 meters. So that's 100 legs in total.

• Which means we have nameplated 1.25 GW if of power in just a 1 x 10 km cross section of the gulf current.

• Now repeat this over 100 km of Gulf stream and you have 125 GW. Repeat this over 1000 km and you have 1.26 TW (or equivalent of US Total nameplate capacity) Gee, Isn't this a solution?

Caveats:

An engineering challenge but there are few bad side effects from producing energy this way

Obviously the capital costs are huge in this case but this does represent a Large Scale Solution as the Gulf current is easily 4000 km in length.

A sensible, large scale local example that would provide florida with 35% of its electrical needs 24x7.

Deployment is very much like that of a wind farm in terms of Unit capacity.