U.S. PATENT 6,531,788                                       U.S. PATENT 7,291,936

March 11, 2003                                                                                                    November 7, 2007

Unlike the intermittent energy that comes from the winds, the tides, and the sun, the energy in the Gulf Stream is relatively steady because it is produced by the earth’s rotation.  It is because of this steadiness that turbines placed in the Gulf Stream, 15 to 20 miles off South Florida, can generate electricity at lower cost than any other environmentally acceptable method.  Because the Gulf Stream Turbines can replace that electricity that is being produced by burning coal, each 1.2 MW machine can reduce the annual emissions of CO2 by about 13,000 tons. 



JOHN H ROBSON – Chairman/Inventor

1167 Lomond Drive

Mundelein, IL 60060

Phone – 847 566 6947






The Gulf Steam is a Steady Coriolis-Force Current

Comparing the Coriolis Current to Tidal Currents

Gulf Stream Turbines Compared to Wind Turbines in Florida

The Invention

Locating the Center of Buoyancy above the Center of Gravity

The Downward Vector Forces Must be Balanced

Balancing the Downward Vector Forces with a Low Tether Hitch Point

Controlling Depth by Moving Center of Buoyancy

The Importance of Inherent Stability

Depth Control System Greatly Simplifies Installation and Recoveries

Gulf Stream Turbines Will Not be Affected by Marine Fouling

Variable Pitch vs. Stall-Controlled Turbines

How Much Electricity Can a Gulf Stream Turbine Produce?

Mind Boggling Environmental Benefits

Gulf Stream Turbines will be Fish Friendly

Comparative Costs of Electricity

Revenues from Electricity, subsidies, and carbon offsets

Gulf Stream Power Can Help Solve Florida's Water Woes

“Greetings from Taiwan


Gulf Stream Turbines should be Mass Produced in Huge Numbers

About the Inventor and Officers



Advantages of the Gulf Stream Turbine Concept

·   Powered by steady Coriolis current produced by the earth’s rotation 

·   Capacity factors comparable to those of fossil-fuel plants

·   Unlike the winds, tides, and sun, current can generate steady electricity

·   No fuel cost

·   Rarely used brakes should never need servicing

·   Elegant design simplicity to give it low O&M costs

·   Silent and invisible   

·   Produces no CO2 

·   Slow turning rotors will not harm marine life

·   Constructed of non-corroding materials

·   Easily mass-produced

·   Depth can be accurately controlled and easily changed by remote control

·   Inherently stable – will not tip, yaw, or pitch

·   Can produce electricity for 5 to 7 cents per kWh during amortization period

·   Electricity Costs will drop to near zero after the capital costs are amortized

·   Eligible for production tax credits of 2.1-cent per kWh

·   Revenues increased from sale of carbon permits with cap and trade legislation

·   Off-peak power can produce hydrogen and to recharge batteries

·   Can supply electricity for the desalinization of salt water 



The Gulf Stream is a Steady Coriolis-Force Current

Though most of the efforts for producing power from renewable energy have been concentrated on capturing energy from the wind and the sun, there is a much better source of renewable energy that is available to our southeastern states that can produce huge amounts of electricity: the Gulf Stream. 

With the exception of the tides, which are produced by the gravitational pull of the moon and the sun, most of the ocean’s energy comes from the sun’s radiant energy.  Though some of that energy is converted by algae into carbohydrates, most is stored as heat and it is the warmed water that activates the global winds that produces the oceans' waves and currents.

In both the Atlantic and Pacific oceans the two trade winds drive an immense body of water westwards over a width of some 50o of latitude, broken only by the narrow belt of the east-going Equatorial Counter-current which is found a few degrees north of the equator in both of these oceans.  A similar westward flow of water occurs in the South Indian Ocean, driven by the southeast trade wind.  Because of the Coriolis effect that is produced by the eastward rotation of our spherically-shaped earth, these winds do not move the water directly toward the east or west, but nudge it off to the right in the Northern Hemisphere and to the left in the Southern Hemisphere; thereby producing giant eddies that are centered in latitudes of approximately 30o N. and S. that rotate clockwise in the Northern Hemisphere and counter-clockwise in the Southern Hemisphere.     

In addition to producing the Coriolis effect that produces the oceans’ gyres, another consequence of the earth’s eastward rotation is that the center of each of those gyres is offset toward the western edge of the ocean basin that confines it.  Because the volume of water flowing toward the poles along the narrower western sides of the gyres is the same as that circulating back toward the Equator down the much broader eastern expanses, the constricted western currents are forced to flow much faster than their eastern counterparts.  This results in such powerful currents as the Gulf Stream in the western North Atlantic, and the Kuroshio in the western North Pacific.  Although most ocean currents are generally too slow or are too far from shore to justify the costs of capturing their kinetic energy, this is not true of the Gulf Stream and the Kuroshio.   


The Gulf Stream starts roughly where the Gulf of Mexico narrows to form a channel, between Cuba and the Florida Keys.  From there the current flows northeast through the Straits of Florida between the mainland and the Bahamas, flowing at a substantial speed for some 400 miles.  The preceding satellite photo shows the Gulf Stream, with the red being the warmest water and blue being the coolest.  The three blue lines in the chart on the right show the location of the Gulf Stream’s central axis. The best sites for the Gulf Steam Turbines would be along this axis, which is between 15 and 20 miles off of Florida’s east coast, between North Palm Beach and Key Largo. As can be seen in the satellite photo, it is well north of this area where the current’s path starts to meander.

Though the Gulf Stream’s peak current velocity may at times reach more than 8 miles per hour in its narrow axis off of Miami, the most likely velocity along the current’s central axis is about 5 mph.  If asynchronous generators are used, as long as the current exceeds about 3 ½ mph, constancy of the speed can actually produce more power than faster currents that have large variations in the velocities – if their rotors, gearboxes, and generators are properly sized for the slower current.  This is because the generators in the slower but steadier currents can operate with higher capacity factors.  (The capacity factor is the amount of power that a plant actually produces in a year, divided by its theoretical capacity.)     



Comparing the Coriolis Current to Tidal Currents

We are interested in the tidal current turbines because they also involve the generation of electricity with underwater turbines and the transmission of electricity to shore.  Also, serious money is being invested in their development – even though their capacity factors will be extremely low.  The ability of a turbine to produce electricity depends on the speed and steadiness of the fluid that is driving it.  Though the usable current velocities that drive the tidal turbines can be about the same as those that would drive the turbines powered by the Gulf Stream, the tidal currents oscillate and can produce at their rated power only for very short periods between the high and low spring tides. 


The preceding graphs show the potential generating potential for tidal turbines that was being planned for Dover, England.  The graph on the left shows the turbines operating at their rated capacities for only a very small percentage of the time.  The graph on the right shows that the peak power would be about 3000 MW during the spring tides, with the average being about 850 MW.  The peak power during neap tides would average about 750 MW, with the average being about 200 MW.  Because the average of the high and low averages would only be about 450 MW, the system’s capacity factors would be incredibly poor.  If the generators had capacities of 3500 MW, the capacity factors would be only about 12%.     

If we superimpose the power that would be generated by a Gulf Stream Turbine having the same combined capacity onto the two graphs, the production would be indicated by the red lines.  The tidal power plants would generate approximately 3,308,288 MW of wildly fluctuating quantities of electricity per year, while the Gulf Stream Turbines – if it had the same 3500 MW generating capacity, would generate 22,353,300 MW of steadier electricity.



Gulf Stream Turbines Compared to Wind Turbines in Florida 

Although wind turbines can produce electricity without burning polluting fossil fuels, there is little wind-power potential in the Southeastern States.  The National Renewable Energy Laboratory has gathered data on a region-by-region basis to identify the nation’s wind-energy resource.  The results of this effort are contained in the Wind Energy Resource Atlas of the United States.  The Southeast region consists of Alabama, Florida, Georgia, Mississippi, and South Carolina.  The report states, “There is little wind energy potential in the Southeast region for existing wind turbine applications (Zabransky et al. 1981).  Even along coastal areas, existing data from exposed sites indicate at best only class 2 at 50 m (164 ft) above ground. The only places in the Southeast region estimated to have class 3 or higher annual average wind resource are the exposed ridge crests and mountain summits confined to northeastern Georgia and extreme northwestern South Carolina.”

The preceding map is from the National Wind Technology Center.  The average wind speeds for specific locations was used to calculate the average annual wind energy in terms of watts per square meter of a turbine’s sweep area.  Geographic areas, as small as one square mile, were assigned a wind power class from 1 to 7.  Those areas that have a wind power class of 3 or higher are considered to be candidates for the development of wind farms.  The National Wind Technology Center states that utility-scale wind turbines can produce electricity for 4 cents per kilowatt-hour on class 6 wind sites that have average wind speeds of 16 miles per hour at a height of 33 feet.  The Southeastern states are not colored because they have a wind power class of 1 and, therefore, no wind-generating potential.  Although the Southeastern states have no winds to generate power – they do have an ocean current that can generate a huge steady supply of very low-cost electricity.

Even when the wind turbines are placed in the best locations, Gulf Stream Turbines will have much higher capacity factors simply because the wind turbines’ energy source is inherently intermittent.  The winds are unpredictable and can fluctuate hourly and have marked seasonal and diurnal patterns.  The wind turbines can make good use of their rated power only when the wind velocities are within a relatively narrow range.  Because the kinetic energy of all moving fluids both increases and decreases with the cube of the velocity, as the wind speed falls below the turbine’s rated speed, the output drops off sharply. 

Those turbines powering asynchronous generators that are directly connected to the grid must spin above minimum speeds to produce usable electricity that has the AC frequency in sync with the grid system.  Below those rotation speeds most electronic wind turbine controllers are programmed to let the turbine run idle without grid connections. In contrast, the Gulf Stream Turbines will be powered by a current having a much more consistent flow rate that will permit them to produce usable electricity virtually one hundred percent of the time.

Because the winds do not blow steadily at even the best wind sites, the electric power that the wind turbines can produce over time is much less than their rated capacities.  This is known in the electricity trade as a low capacity factor.  Wind turbines also frequently produce the most power when the demand for that power is at its lowest.  Low capacity factors and still lower dependable on-peak capacity factors are the major source of the wind power’s problem.  For example, in California, wind power operated at only 23 percent realized average capacity in 1994.  That compares with nuclear plants, with capacity factors of about a 75 percent; coal plants, with capacity factors of between 75 and 85 percent, and gas-fired combined-cycle plants, with capacity factors of about 95 percent of their average designed capacity.  Depending on where the water turbines are placed, they can operate with capacity factors equal to those of many fossil-fuel plants.  Although there will be some changes in the current’s velocity, caused by the moon’s tidal effects and the steadiness of the trade winds, the only renewable energy source having higher capacity factors than well-placed Gulf Stream Turbines would be those existing hydroelectric plants at those dams that have sufficient water in their reservoirs. 

Capacity factors are extremely important to the efficiencies and economics of both wind and water-powered generating plants.  Let’s assume that a giant wind turbine has a “rated wind speed” of 25 mph and a rated output capacity of 2,316 kilowatts per hour.  Multiplying that hourly output capacity by the 8,760 hours in a year gives a theoretical capacity of 20,288,160 kilowatt-hours per year.  But because the capacity factors for wind turbines are between 17 and 37 percent, the actual output of the machine would only be between 3,448,987 and 7,506,619 kilowatt-hours per year.   If any wind turbines were to be placed in Florida, their capacity factors should be less than 15 percent, which would produce less than 3,043,224 kilowatt-hours per year.     

Because the Gulf Stream is driven by our planet’s spinning on its axis and the steady trade winds, its flow rate off of South Florida is nearly constant..  Properly placed water turbines that have the same rated capacity as the aforementioned wind machines should have capacity factors of between 75 and 95 percent.  Because of these much higher capacity factors, the actual output for the Gulf Stream Turbine, with the same rated capacity, should be between 14,201,702 and 19,273,752 kilowatt-hours per year – or more than 5.6 times the electricity produced by a wind turbine having the same generating capacity operating in Florida.  As has been previously stated, there are no potential wind sites in our southeastern states. 



The Invention

The Gulf Stream Turbine is a unique concept for a self-supporting submersible power plant that utilizes the laws of physics to maintain stability and to control depth, and permit it to operate safely near the surface and to descend to greater depths to get below the most turbulent water during storms.  To neutralize the torque that would otherwise roll a tethered generator in the direction opposite to the turbine’s rotation, the machine has two turbines and generators that rotate in opposite directions so that the torque produced by one turbine is neutralized by that of the other.  The two generators and gearboxes are housed in watertight, rear-facing nacelles that are located below and to each side of a torpedo-shaped buoyancy tank that extends fore and aft.  The weight of the heavy generators and gearboxes serve as ballast to get the structure’s center of gravity far below its center of buoyancy (the center of gravity of the displaced water).

The invention is based on the relative positions of buoyancy and weight to obtain stability and on a unique method of using leverage to balance the hydrodynamic lifting forces to the changing downward vector forces to control depth.  Because these machines are constructed of light carbon-fiber and fiberglass, they will require less displacement than if they were made of metal and – more importantly – they will not corrode.  Because of the Gulf Stream Turbine’s mechanical simplicity, they can generate electricity for extremely long periods – even years – with no servicing.  The actual conversion of the water’s kinetic energy into electricity utilizes the same technologies that are used by the wind-turbine industry.  However, unlike the wind turbines, these machines will operate in a dust-free environment, will not contend with widely fluctuating velocities, and will be able to produce usable power 24-7. 






Locating the Center of Buoyancy above the Center of Gravity

The following drawing shows a Gulf Stream Turbine tipped at an exaggerated angle of 20 degrees to illustrate how the forces that are produced by having the center of buoyancy high above the center of gravity can prevent tipping.  The location of the center of gravity is shown by the green dot and the center of buoyancy by the blue dot.  If the machine were tipped, the length of the righting moment will equal the length of the righting arm (the horizontal red line projecting to the right of the green dot to the blue line that extends vertically downward from the center of buoyancy), multiplied by the machine’s weight.  The length of that righting arm will equal the distance between the centers of gravity and buoyancy, multiplied by the sine of the angle of tilt.  For any given weight and angle of tilt, the righting moment will be proportional to the distance between the center of buoyancy and the center of gravity.  If that distance were doubled, the righting moment for any angle of tilt would also be doubled.  U.S. Patent 6,531,788 is the only patented submersible power plant that has its center of buoyancy located above its center of gravity.

Though the vertical separation between of the center of gravity and the center of buoyancy is the most important principle of physics that provides the Gulf Stream Turbine with its great inherent stability, the invention has other features that add to that stability.  For example, the hydrofoils are mounted high on the buoyancy tank, placing their lifting forces far above the center of gravity, which further increases the righting moment.  The hydrofoils’ dihedral increases the structure’s stability still more because the lower hydrofoil of a tipped machine will produce more lift than the raised hydrofoil.  Additionally, by having the anchor line’s attachment point located far below the lifting forces adds even more to that stability.  And lastly, the placement of the vertical and horizontal tail fins at the rear of the buoyancy tank places the structure’s centers of lateral and vertical resistance far behind the anchor-line’s attachment point to prevent yawing and pitching, and to keep the structure facing directly into the current. (The center of lateral resistance is that theoretical point from where an applied force could move the structure sideways without it rotating.  The center of vertical resistance is that theoretical point from which a force could move the structure vertically without it rotating.)   



The Downward Vector Forces Must be Balanced

Depending on the downward angle of the anchor line at its attachment point, the downward vectored forces, produced by the horizontal drag from the turbines, could be considerable.  As the angle of the anchor chain increases from the horizontal, that downward force will increase as a percent of the unit’s total horizontal drag.  If the submersible power plant were prevented from moving lower by an opposing lifting force, the downward vector force would increase in proportion to the tangent of the anchor line’s downward angle where it attaches to the unit.  If that downward angle remains constant, then the downward vector force will increase in proportion to the kinetic energy, increasing with the cube of the current’s velocity.  To prevent this increasing downward force from pulling a unit deeper, that downward force must be balanced with an equal and opposite lifting force.  This can be done by either increasing the unit’s buoyancy, by using hydrofoils to provide hydrodynamic lift, or by a combination of both.  If the downward force is not equalized, the unit will be pulled down to that depth where the angle of the anchor chain’s pull will be reduced sufficiently so that the resulting downward vector force will equal the upward forces being provided by the buoyancy and hydrofoils.  The forces would then be in equilibrium and the unit would remain at that depth – as long as there were no changes in the current’s velocity or in the demand for electrical power.  An increase in either would further increase the horizontal resistance and cause the unit to move still lower.  Likewise, if the load on the generator were reduced, the turbine’s rotors will turn with less resistance, producing less drag, which would reduce the downward vector force and cause the unit to move higher.



Balancing the Downward Vector Forces with a Low Tether Hitch Point

The center of frontal resistance is that theoretical point where all the drag forces are balanced so that, if the structure were to be towed from that point, it would move forward without rotating.  The simplest method for balancing the changing downward vector forces is to have the anchor-line’ attachment point located at a proper distance below that center of drag.  Then, if an increase in the horizontal drag should cause an increase in the downward vector force, the increased pull on the low anchor-line attachment point will place a rotational force on the entire machine to raise its nose and drop the tail.  This rotational force does not need to cause the structure to actually rotate, but must increase the lifting force being produced by the hydrofoils enough to balance the increased downward vector force.

If there is no change in the angle of the anchor line and no change in the hydrofoils’ angle of attack, the rotational force will change proportionally with both the horizontal drag and the tension on the anchor line.  The key to this leverage system for creating the proper amount of hydrodynamic lift to balance the downward forces at varying current velocities is the relationship between the loading on the hydrofoils D and the distance (the length of the lever arm) between the center of drag A and that point C that is perpendicular to the line that extends the angle of the anchor line from B to F.  If buoyancy is used to support almost all of the structure’s weight and the lifting forces produced by the hydrofoils are used to balance the downward vector forces, once the correct hitch point height B has been determined for a given velocity – because all of the forces will remain proportional – the machine will tend to remain at the same depth in currents of differing velocities and with changing generator loads. 



Controlling Depth by Moving Center of Buoyancy

The Gulf Stream’s central axis, where the current flows the fastest, is located about 15 to 20 miles off of Florida’s east coast, between North Palm Beach and Key Largo.  Though the depths along this axis vary, they are generally between about 800 and 1,300 feet.  Because the current’s velocity is normally greater near the surface, any submersible power plant that is to efficiently generate electricity from that current must also be able to operate near that surface – yet safely below ship traffic.  And it should also be possible to substantially increase their depths to avoid the surface turbulence caused by hurricanes.  Though the previously described low-hitch-point system can control the depths to some degree, because that system receives no input concerning a machine’s actual depth, it cannot reliably prevent it from getting too close to the surface.  Though U.S. Patent 6,531,788 describes how this problem can be avoided by securing a line from the machine to a weight on the ocean floor, the use of such a bottom weight would make the installations and recoveries much more difficult – as well as cause other problems.      

Previously I have described how the Gulf Stream Turbine utilizes the vertical separation of its centers of buoyancy and gravity to prevent tipping.  This same principal of physics that causes a free-floating object to float with its center of gravity directly under its center of buoyancy can also be used to control the depth by simply moving the center of buoyancy or center of gravity forward or backward, relative to each other.  These movements will raise or lower the machine’s nose to adjust angle of attack of the attached hydrofoil to produce the proper hydrodynamic lifting force that is needed to precisely balance the downward vector force when the machine is at the proper depth.  U.S. Patent 7,291,936 adds such a depth control system that measures the depths by the hydrostatic pressures, which will increase by .4444 psi per foot of depth.      

Earlier papers and U.S. Patent 7,291,936 describe changing the relative positions of the centers of gravity and buoyancy in terms of moving the center of gravity in relation to a fixed center of buoyancy to control the depth.  This paper describes that movement in terms of moving the center of buoyancy in relation to a fixed center of gravity.  Though the results will be the same, it is easier to understand because those parts of the buoyancy tank that will have the same density as that of the displaced water will have no effect on the structure’s buoyancy other than that water will occupy the same space that would otherwise by filled with the much more buoyant air.  

In the following illustration the center of gravity is located at the green dot I.  The blue dots E and F are the extreme theoretical locations of the center of buoyancy with the line F-G being the line that would become vertical if the center of buoyancy were at F, and E-H being the vertical line if the center of buoyancy were at E.  The center of buoyancy for an operating machine would be between K and L, with the verticals being K-M and L-N. 

The following schematic is of a modified version of the Gulf Stream Turbine described in U.S. Patent 7,291,936 that will make the installations and removals much easier – as well as provide total control of the depths from remote locations.  The buoyancy tank is divided into four compartments, A, B, C and D, with the compartment D being combined with the interior volume of the hydrofoils 17.  There is a water transfer system 5, capable of moving ballast water back and forth between the two end compartments A and D.  This water transfer system consists of a first pump 1, a first pipe 6 and a first special check valve 4, capable of transferring ballast water from the rear compartment D to the front compartment A.  The second part of this transfer system consists of a second pump 2, a second pipe 7 and a second special check valve 3, capable of transferring ballast water from the front compartment A to the rear compartment D.  The two pumps 1 and 2 are controlled by a pressure switch 26 that is activated by the hydrostatic pressures going either above or below limits that can be controlled from a remote location. The special check valves 3 and 4 will not only not allow water to flow in the wrong directions through the pipe 7 and 6, but they will also not allow water to flow in the right direction if the pressure in the pipe is not above a minimum.  This is to prevent the water from siphoning between the end compartments due to differences in their levels. Each special check valve is failure proof, consisting of a heavy ball that rests upon the valve's intake port to prevent low-pressure water from flowing through the valve in the wrong direction.  When the pump is running, the increased pressure will lift the ball off the valve's inlet port to allow the water to move through the valve in the right direction.

Partition 20 that separates compartments C and D is connected by the pipe 27 that allows water to flow from compartment C into compartment D after compartment C is full.  The pipe 27 extends to the front end of compartment C so that compartment will stay full as the loading of compartment D causes the buoyancy tank’s rear end to sink lower.  Compartment C should remain full because it should have near neutral buoyancy, its purpose being primarily to increase the distance between the two end compartments that are used to adjust the center of buoyancy.  By moving the ballast water from one of the end compartments to the other, the changing volumes of water will produce opposite changes in the volumes of the lighter air, which will move the center of buoyancy in the direction opposite to that of the moving water.  Partition 20 also has an opening to the pipe 6 that transfers water from compartment D to compartment A.  There is also a second opening through which water from compartment A is transferred through pipe 7 to compartment D.  The bulkhead 18 has no openings other than for these same pipes and for a vent 22 that equalizes the air pressures between compartment A and B, and a vent pipe 24. Vent 22 uses a buoyant ball in a cage that will allow air to pass between compartments A and B, but not water.  Pipe 24 links the air space in compartment A with highest points inside the raised tips of the two hydrofoils at 8 to allow air to move between compartment A and the tips of the hydrofoils.  Compartments A, C, and D have baffles 23 that restrict the movement of the ballast water.  Compartment B (not flooded) contains the electric pumps 1 and 2, the special check valves 3 and 4, and other electrical gear.  This space is accessible through hatch 16.  Partition 19 is watertight with the pipes 6, 7 and 24 passing through it.  Each of the machines is linked electronically to a command center to permit the settings of the depth control switches 26 on all of the machines in a string to be simultaneously changed.  This feature permits all of the machines to be raised to make them easily accessible for servicing – or lowered to get them below the turbulence during storms. 

In addition to the pressure-controlled system that controls the machine’s depth, the schematic drawing on page 21 also shows a schematic of a ballast-water purging system that is similar to the one described in U.S. Patent 7,291,936 that uses air that is pressurized inside the buoyancy tank to expel the water.  The valves 9 each have a buoyant ball in a cage that floats above the outlet as long as it is flooded.  As the last of the ballast water is being purged from each compartment, the ball drops into the valve’s outlet to stop the pressurized air from escaping to conserve it to purge the water from the other compartments. 



The Importance of Inherent Stability

There is an important difference between an inherently stable submersible power plant and one that is not.  An inherently stable plant uses those innate forces that are produced by the relative locations of its lifting and downward forces to maintain an unchanging attitude in relation to both the direction of the current flow and to the horizontal plane. The source of that inbuilt stability cannot be separated from the machine’s design, and it will remain level and under control without any separate control system.

In contrast, the inherently unstable submersible power plant will not remain stable without some type of separate mechanical control system that constantly monitors the machine's attitude and makes those control adjustments that are needed to keep the machine level and under control.  The obvious danger with such a design is that, should any part of the machine’s control system fail, there will be no innate force to prevent the machine from rolling and going out of control.  The combination of the submersible power plants’ close proximities, their long anchor lines, and an inherently unstable design is a recipe for a rapidly spreading disaster. 



Depth Control System Greatly Simplifies Installations and Recoveries

The hydrostatic-pressure-activated depth-control system, working with the low-hitch point system creates benefits that exceed those that could be provided by the two systems operating separately.  Working together, they will make the installations and recoveries relatively easy.  During the initial installations, the proper amount of fresh or filtered ballast water is pumped into compartment C of each of the Gulf Stream Turbines that have been formed into strings that are floating on the surface.  This water will first fill compartment C of each of the machines and then pour into compartment D and the hydrofoils.  The resulting loss of buoyancy at the rear of the buoyancy tanks will cause the sterns to sink lower, which will increase the lifting forces produced by the hydrofoils, which will keep the ballasted machines hydroplaning on the surface.  After the buoyancy tanks of all of the machines have been filled with the proper amount of ballast water, switches can be thrown to energize the generators’ stators to start producing electricity, and to activate the pressure-controlled depth control systems that will cause all of the machines to descend in unison to the desired depth. 

The pressure activated depth-control system also will allow a string of Gulf Stream Turbines to be returned to the surface by simply overriding the depth control systems to turn on all the pumps on all of the machines that will transfer the ballast water from their front compartments to their rear compartments.  After there resulting increases in the hydrodynamic lifting forces have lifted the machines to the surface, the buoyancy tanks can be purged on those machines that are to be removed.  The anchor lines then can be disconnected from the extension cables, the extension cables disconnected from the anchor lines, the electricity extension cables disconnected from the electricity collecting cables, and the Gulf Stream Turbines can be hoisted from the water.

The following drawing shows the electricity collecting cable that carries the electricity from all of the Gulf Stream Turbines that are in a string to where the cable connects to another cable that follows one of the anchor lines down and forward to where the cable connects to the transmission cable that is on the seafloor, near the anchor.  This cable arrangement will allow the Gulf Stream Turbines to swing laterally to accommodate moderate variations in the direction of the current. 


The first step in the installation process is the placing of the individual anchors. Using a typographic map of the ocean floor, an echo-depth finder, and GPS, each anchor is accurately placed.  As each anchor reaches the bottom, the large buoyant spool onto which its neutrally buoyant anchor lines had been wound and to which it is still attached, can be rolled into the water to serve as a float to support the top end of the anchor line. 


The preceding two drawings show a concept for catamaran designed for accurately placing the anchors, anchor line, and, later, the electricity collecting cable segments.  The large deck area is for carrying and installing these segments.  The following three drawings show a catamaran that is designed for transporting and installing the Gulf Stream Turbines.  Both watercraft are shown equipped with two forward and two rear jet drives that can rotate 360 degrees to permit them to maintain position in a strong current. 




Gulf Stream Turbines Will Not be Affected by Marine Fouling 

Marine fouling negatively affects the efficiencies of ships because it decreases their speed and increases their fuel consumption.  Fouling begins with a layer of green slime that forms on the hull, which paves the way for other plants and animals, such as algae and barnacles, to become attached to the hull’s surface and grow.  Though these organisms cause problems for ships, there are two reasons why they should not affect the efficient operation of the Gulf Stream Turbines. 

Fouling begins when a ship remains in the still waters of harbors for long periods and its hull is not protected with antifouling paint.  Because the Gulf Stream Turbines will always be in constantly moving water, the spores and fertilized eggs of the various marine plants and animals can not remain in contact with its surfaces long enough to stick.  Though probably not necessary, a slippery coat of a silicon antifouling paint would eliminate any possibility of fouling for many years and possibly even for decades.  

Also, unlike the ships, the Gulf Stream Turbines will not be going anywhere nor will they be consuming any fuel.   


Variable Pitch vs. Stall-Controlled Turbines          

Serious damage can occur if an excessively strong fluid velocity should overpower an asynchronous generator to force it to spin too fast for its electricity to remain in sync with the grid.  Wind turbines use both pitch-controlled and stall-controlled systems to avoid this problem.  On a pitch-controlled wind turbine the turbine’s electronic controller checks the power output of the turbine several times per second.  A computer then changes the pitch of the blades a few degrees every time the wind changes to keep the rotor blades at the optimum angle to maximize output for all wind speeds. 

The stall-controlled wind turbines have fixed blades that are designed so that they will start to stall when the wind’s velocity goes above the turbine’s rated speed.  As the rotational speed of the rotor is effectively constant, limited by the grid’s 60-Hz current that is magnetizing the generator’s stator, the angle of attack of the blades will increase with an increasing wind speed.  As the wind speed increases above that of the turbine’s rated speed, the angle of attack of the air passing over the blades increases so that the blades will begin to stall, causing the lift to drop and drag to increase to a more inefficient lift-to-drag ratio to reduce the driving torque.  These blades are typically designed so that stall occurs at the rated wind speed, with the most optimal angle-of-attack setting occurring earlier. 

Because the pitch of the blades is fixed, the turbine rotor is mechanically simple as there is no blade pitch system required, thus eliminating the need for hydraulics, electrics, or pitch bearings. Because of their mechanical simplicity, the stall-controlled blades should prove to be an excellent choice for the Gulf Stream Turbines.  The following shows the stall-controlled blades that are used on Verdant Power’s six turbines that have been producing power from the East River of New York City.    


The stall-controlled turbines that are being used on Verdant Power’s East River Project

(Because the stall-controlled rotor blades cannot be feathered, Verdant Power had a few problems with the blades breaking as the rotors were being lowered into the fast-moving water.   Because the rotors were not turning, the force of the river’s current pushing against the outer portions of the non-rotating blades were perpendicular to their surfaces, which caused some of the blades to break as they are being lowed into the rapidly moving water.  This isn’t a problem when installing the wind turbines because their rotors can be installed during periods when the winds aren’t blowing.  However, when installing the Gulf Stream Turbines in the constantly flowing Gulf Stream, it may be necessary to allow the installing vessels to drift with the current while the rotors are being submerged, which would have the same effect as stopping the current.  After the blades are in the water, power can then be applied to the vessel to stop the drifting.  Then, because the pitch of the blades is greater toward the hubs, as the drifting is slowed, that inner portion of the blades will start the rotor turning to reduce the angle of attack of the moving blades to the moving water.) 


How Much Electricity Can a Gulf Stream Turbine Produce?

The fact that the most common generators that are now being installed on new wind turbines have capacities of 1500 kW or more does not mean that the generators on the Gulf Stream Turbines must also be large to be efficient.  The major reason why the wind turbines have been getting bigger is – because the larger machines are also taller – they can capture energy from the higher winds that are stronger.



Because the velocity of the Gulf Stream’s current will not increase with depth, there will be no increase in power, per square meter of sweep area, by having very large rotors and generators.  The following table shows the sizes of the rotors required to power generators of various sizes in a 5-mph current and the total megawatts of electricity that a Gulf Stream Turbine’s two generators would produce per year.   



Mind Boggling Environmental Benefits 

On May 27, 2009, The Wall Street Journal reported that the chief executives of such companies as BP, PepsiCo, and Duke Energy called for an immediate and substantial change in the trend of rising global greenhouse-gas emissions, which they said must peak and begin to fall within the next decade and be reduced by at least half of the 1990 levels by 2050.  Quantitatively, the most important of the greenhouse gases causing global warming is carbon dioxide, and the generation of electricity is responsible for 40% of all US CO2 emissions.

Every kilowatt-hour of electricity that can be generated with water or wind can replace an equal amount of electricity that is now being generated by burning a fossil fuel.  According to the EIA the gas-fired power plants produce approximately 1.321 lb of carbon dioxide for every kWh of electricity that they produce.  A Gulf Stream Turbine that is equipped with two 600-kW generators would generate 8,941,300 kWh of electricity per year.  To produce the same amount of electricity as the Gulf Stream Turbine, a gas-fired power plant would need to consume 52,650,000,000 Btu of natural gas and emit 5,905 tons of carbon dioxide into the atmosphere.  A coal-fired plant producing that same amount of electricity would emit about 13 thousand tons.     

According to Our Ecological Footprint, (Wacklermagel & Rees, 1996), a forest absorbs about three US tons of CO2 per acre of trees per year.  If one acre of forest can absorb 3 tons of CO2 per year, then to absorb the 5,905 tons of CO2 that would be emitted by a gas plant that would produce the same 8,941,300 kWh that would be generated by the Gulf Stream Turbine, would require 3.075 square miles of forestland.  To absorb the 13,000 tons emitted by a coal-fired plant would require 6.768 square miles of forest.  Though the number of Gulf Stream Turbines will be limited due to the effects that the slowing of the current could have on Europe’s climate, the total numbers of those turbines could eventually reach between 10,000 and 30,000.     

Unlike fossil-fuel powered plants, the amount of power that will be generated by the Gulf Stream Turbines will not be affected by the demand for the electricity but by the strength of the current.  During off-peak periods, any surplus power that might be generated can be used to recharge the batteries of electric cars and plug-in hybrids, and to produce hydrogen for those cars that use fuel cells – all of which will further reduce the emissions of CO2 and our nation’s dependence on foreign oil.  



Gulf Stream Turbines Will Be Fish Friendly

The Gulf Stream Turbines will not harm fish or other marine life because its rotors will be turning no faster than about 2.25 rpm.  (This is based on a rotor that is sized to generate 600 kW of electricity from a 5-mph current.  The remainder of this section was redacted from the article, Hydro Green Energy Hydrokinetic Technology Proves Fish Friendly, which appeared on the website of on January 10, 2010:  

The first and only direct fish survival study performed on a hydrokinetic turbine shows that the technology is exceedingly safe for fish.  The hydrokinetic power turbine tested was designed and manufactured by Texas-based Hydro Green Energy, LLC, which also operates the unit at U.S. Army Corps of Engineers Lock and Dam No. 2 in Hastings, Minn.  The 82-page study results were filed at the Federal Energy Regulatory Commission, the federal agency that regulates the hydropower industry.  The fish survival study was performed during the summer of 2009 at the only commercial, FERC-licensed hydrokinetic power plant in the United States, the 100-KW Hastings project.

At the Hastings project, Normandeau Associates, a consulting firm with 40 years of experience in providing ecological, environmental and natural resources management services, evaluated the direct effects to fish of the first of two hydrokinetic units.  The consulting firm conducted the fish survival study using their “HI-Z Turb N’ Tag” methodology. Normandeau’s patented methodology has been utilized at nearly 50 conventional hydro projects and by the Department of Energy, but never on a hydrokinetic turbine.

This methodology uses a controlled experiment approach and produces comprehensive, statistically reliable and verifiable results on injury and survival of fish passed through a turbine, spillway or over falls.  To accomplish this task, Normandeau deployed 502 balloon and radio tagged fish of a variety of species and sizes. 402 fish swam through HGE’s hydrokinetic turbine, which rotates at 21 revolutions per minute, and 100 were allowed to swim freely in the river near the turbine.  Environmental scientists studied fish survival and injury rates of both groups after recapture of nearly all the tagged fish.

Only one fish out of the 402 that were introduced into the hydrokinetic unit showed evidence of direct physical harm, and Hydro Green Energy reports that this may have been due to the fact that the fish was outfitted with a balloon tag, causing it rise to the surface to interact with the hydrokinetic device in a manner that otherwise would never occur.

“The comprehensive study performed on our hydrokinetic turbine wholly confirms what we had modeled with a computer before the turbine was installed, as well as what we knew in our minds: our hydrokinetic turbine is an extremely environmentally friendly technology,” said Wayne F. Krouse, Chairman and CEO of Hydro Green Energy. “From the first day this project was envisioned, Hydro Green Energy committed itself to performing this study as a way to not only advance our technologies and projects, but to advance the global hydrokinetic power industry as a whole. While the study specifically validates our technology, it also validates our pre-installation computer modeling, which can be performed on other technologies with a high degree of confidence.”




Comparing Electricity Costs

The per-kilowatt cost of generating electricity, regardless of the method used, consists of the fixed costs, fuel costs, and the non-fuel operation and maintenance (O&M) costs.  It is the high capacity factors and the low operating costs that make it possible for the Gulf Stream Turbines to produce more electricity and greater revenues than any other method of generating electricity, per dollar invested.   

Gulf Stream Turbines’ Low Fixed Costs  

The amount of power that can be produced is the single most important factor that affects the costs per kWh of the power generated.  Because there will be no fuel costs and low O&M costs, the costs of the electricity that a Gulf Stream Turbines produces will basically be the amortization costs, divided by the kWh of electricity generated during the amortization period.  (They can also be based on the power produced during the expected life of the machine.)  The first of the following two tables gives the amortization costs per kWh for Gulf Stream Turbines that have a capital cost of $2,000 per kW, with the amortization periods and interest rates that are indicated.  The second table is for those Gulf Stream Turbines that have a capital cost of $2,500 per kW.  Obviously, the per-kWh cost of the Gulf Stream Turbines’ electricity will drop to near zero at the end of the amortization period because of the only costs remaining will be the low O&M costs.  

Gulf Stream Turbines’ Lower O&M Costs

There are several reasons why the O&M (operation and maintenance) costs for the Gulf Stream Turbines will be substantially lower than those for the wind turbines.  Unlike the winds that must contend with winds that can vary from zero to hurricane-force velocities, the velocities of the Gulf Stream Turbine’s current will be much more even.  This makes it possible for their generators to continuously produce electricity by having the generator’s high cutoff speed set higher than the current’s highest expected velocity and its low cutoff speed set lower than the current’s lowest expected velocity.  Because the Gulf Stream’s highest velocity will be too slow to cause any damage, the only time that its brakes should ever need to be used will be during those brief periods when the rotors are slowed to get the generator’s cycles synchronized with those of the grid.  Because of its failure-proof design, the Gulf Stream Turbines’ O&M costs should be less than 2% of their levelized capital costs (the capital costs, divided by the kWh of electricity generated over the machine’s life).  The O&M costs will be very low because the moving parts on each Gulf Stream Turbines consist of just of two rotor hubs, two slow-speed shafts, two planetary transmissions, two high-speed shafts, two generators, two seldom-used brakes, two water pumps, a remotely controlled pressure switch and a few totally fail-proof valves that will never break or wear out. 

Following are some of the wind turbines’ maintenance costs that the Gulf Stream Turbines can avoid:  

·       The brakes should not need servicing because they will seldom be used and then only briefly  

·       Using stall-controlled rotors blades eliminates those problems with pitch-control  

·       Excessive current velocities can be curbed by increasing depths to slower water

·       There will be no yaw-control system that will need servicing or repair  

·       Steadiness of the current’s velocity will eliminates breakage caused by excessive forces     

·       There will be no dust from brake wear or from the environment to cause problems

·       The structures will be made of non-corroding materials and have no moving parts  

Wind Turbines’ Fixed Costs 

According to the report Projected Costs of Generating Electricity 2005 Update, published by the International Energy Agency “…For intermittent renewable sources (of energy) such as wind, the availability/capacity factor of the plant is a driving factor for levelized costs of generating electricity…  They range between 17% and 38% for onshore plants, and between 40% and 45% for offshore plants except in Germany.”   Because of Florida’s low wind-power potential, any wind turbines placed in that state would almost certainly operate with capacity factors of less than 15%.   

Typically, those wind turbines that are installed by developers are financed over 12 years and those installed by investor-owned utilities are financed over 20 years.  Capitalization costs range from about $1,500 to $2,500 per kW of capacity.  The following table provides the amortization costs per kWh for wind turbines that have a capital cost of $2,000 per kW of generating capacity, operating with a capacity factor of 15% over various amortization periods and at different interest rates. 

Because the wind turbines in Florida would have capacity factors of less than 15%, if they were financed over 12 years at 5%, they would have an amortization cost of approximately 42.2 cents per kWh.  If they were financed over 20 years, that cost would be 30.11 cents per kWh.

 Wind Turbines’ O&M Costs 

 According to the website of the EWEA (Europe Wind Energy Association):

Operation and maintenance (O&M) costs constitute a sizeable share of the total annual costs of a wind turbine.  For a new turbine, O&M costs may easily make up 20-25 percent of the total legalized costs per kWh produced over the lifetime of the turbine.  If the turbine is fairly new, the share may be only 10-15 percent, but this may increase to at least 20-35 percent by the end of the turbine’s lifetime.  As a result, O&M costs are attracting greater attention, as manufacturers attempt to lower these costs significantly by developing new turbine designs that require fewer regular service visits and less turbine downtime. 

To the wind turbines’ higher fixed costs and higher O&M costs must be added the costs of the additional gas that would be consumed by the standby generators that will be needed when the winds aren’t blowing.  Because the capacity factors for Florida’s wind turbines’ would be no more than 15% and those for the Gulf Stream Turbines would be about 85%, the reductions in gas use achieved from using the wind turbines would be only about one-sixth of what would be achieved with Gulf Stream Turbines that have the same generating capacity.  A renewable energy system having a capacity factor of 15% would reduce the amount of gas that would be consumed by only about 17.6% from what would be consumed if the standby generators were to produce all of the electricity.  Though neither the wind turbines nor the Gulf Stream Turbines would have any direct fuel costs, there would be huge differences in the amounts of fuel consumed by their standby generators. 

Many More Nuclear Plants Are Needed

The estimates of the costs for new nuclear power plants place them among the costliest private projects ever undertaken.  Even though the projected costs for new nuclear reactors have been increasing by 15% per year and have quadrupled over the past decade, the utilities that are promoting new nuclear power assert that it is their least costly option because the renewable sources of wind, tidal, and solar energy are intermittent and unreliable. 

The Wall Street Journal (Dec 5-6, 2009) reported that escalating costs of nuclear power have spooked CPS Energy, a city-owned utility in San Antonio, to reconsider going ahead with a venture with NRG Energy to build two next-generations nuclear reactors in Texas.  City officials have said that the cost estimates for the two-reactor project have ballooned to $12.1 billion from a preliminary estimate of $8.6 billion in 2007.  NRG Energy says that it is confident that they will be able to get the costs below $10 billion, before about $3 billion in financing costs are added.  Each of the two power plants would have a capacity of 1,350 megawatts.  With the capital costs totaling $13 billion, those costs would be $4,815 per kW of capacity.  Recent estimates for other capital cost for other nuclear plants have implied capital costs at between $5,000 and $7,000 per kW.  The plants take between 8 and 12 years to complete.   

If the two nuclear plants that cost $13 billion were to operate at the same 85% capacity factor as the Gulf Stream Turbines, they would generate 20,117,970,000 kWh of electricity per year.  If those same funds were used to purchase Gulf Stream Turbines that cost $2,000 per kW of installed capacity, those billions would purchase enough Gulf Stream Turbines to produce 48,432,041,667 kWh per year.  It the Gulf Stream Turbines were to cost $2,500 per kW of installed capacity, the number of machines purchased with that $13 billion would produce 38,754,633,333 kWh per year. 

In addition to the Gulf Stream Turbines producing as much as 2.7 times the electricity per dollar invested, the Gulf Stream Turbines would also no fuel costs and much lower non-fuel O&M costs.  According the Nuclear Energy Institute (NEI), the total annual costs associated with the “burnup” of nuclear fuel resulting from the operation of a nuclear power plant is based on the amortization costs associated with the purchasing of the uranium, conversion, enrichment, and fabrication services, along with the storage and shipment costs, and inventory (including interest) charges, less any expected salvage value.  For a typical 1,000 MW reactor, the approximate cost of the fuel for one reload (replacing one third of the core) is about $40 million, based on an 18-month refueling cycle.  The average fuel cost at a nuclear power plant in 2008 was 0.49 cents per kWh. 

There are also the annual costs associated with the operation, maintenance, administration, and support of a nuclear power plant.  Included are the costs of labor, material and supplies, contractor services, licensing fees, and miscellaneous costs such as employee expenses and regulatory fees.  The average non-fuel O&M cost for a nuclear power plant in 2008 was 1.37 cents per kWh.  Based on the figures for the amortization costs, fuel costs, and non-fuel O&M cost, the total costs for the electricity produced by the nuclear plant would be between 26.85 cents and 31.85 cents per kWh. 

Though the costs of nuclear power will be higher than those for that electricity that can be generated with the Gulf Stream Turbines, we must build many more of them because – other than the Gulf Stream Turbines, conventional hydroelectric, and geothermal – none of the other sources of renewable energy can supply reliable electricity. 

Natural Gas

Even though the recent development of the horizontal drilling and hydraulic fracturing technologies have made available much of the shale gas that formerly had not been economically producible, any energy policy that encourages an increasing long-term dependence on that fuel can only result in the total collapse of our economy, sometime after about 2040.  Though the development of the new drilling technologies may have increased the proved gas reserves to 100 years (based on the present rate of consumption), the production of that gas will not remain at the present level for one-hundred years and then suddenly drop to zero in 2110.    


The preceding graph shows a forecast of possible future gas production that is based on the assumption that rate of gas production will increase rapidly during the next few decades, spurred by the need to satisfy the growing demand that will be caused by much higher oil prices and by the reductions in coal use.  The problem will appear suddenly when the gas producers are no longer able to increase production fast enough to satisfy the increasing demand – while replacing that production that will be being lost due to depletion.  Unless there are enough new non-polluting nuclear and other nonpolluting power sources installed and operating before the production of gas starts rounding over (the graph shows this occurring in the late 2030s) there will be a serious problem that will be caused by an increasingly unsatisfied inelastic demand.   

On January 2, 2001, the Wall Street Journal ran a front-page story that said, "In California, where natural gas powers many electricity plants and state rules until recently banned electricity producers from buying on the futures market, the cash price has risen, though fleetingly, to as high as $60 per million BTU.”  This astronomical price proves that, whenever there is an unsatisfied inelastic demand, the prices of the gas will be determined only by what people will be willing to pay to get the gas that they need.  Because the demand for gas is inelastic, a slight shortage can cause the prices of gas to increase several fold.  Because the resulting high gas prices would reduce discretionary spending, they would cause a far more serious economic problem than the present recession that has been caused by unsound financial policies.  

Though the new horizontal drilling and hydraulic fracturing technologies have allowed us to rapidly increase the gas production for perhaps the next 30 or 40 years, it is important that we realize that these technologies have only postponed supply of gas to avoid a serious gas shortage that had been eminent, it is important that we realize the these technologies will not the these technologies did not remove the danger of the gas shortages causing an economic disaster – they have only postponed the inevitable – postpone that natural gas shortage that had been eminent – the development of the shortages of conventional gas depression than the present one.  There will be no way to end a recession that will be caused by the energy shortages other than to other sources of energy. 




Revenues from Electricity, Subsidies, and Carbon Offsets 

Electricity Prices Follow Natural Gas Prices

The wholesale prices of electricity tend to follow the wholesale prices of natural gas because the price of the electricity includes the cost of that fuel that is consumed to produce it.  It is because the operating costs are the highest for the gas-fired power plants it is that electricity that is sold on the wholesale market.  The close relationship between the electricity and gas prices can be seen by comparing the prices in the following two graphs after January 1, 2008. 



Since the spot prices for electricity hit their peak in July of 2008, the drop in demand for gas from industry and the electric utilities, plus an increase in the production of unconventional gas from shale, created a gas glut that caused the gas prices to slump to $2.00 per MBtu and the electricity prices to fall to about 2.5 cents per kWh ($25/MWh) in September of 2009. 


The preceding graph that is on the left shows the Henry Hub daily spot prices between January 4, 2009 and January 4, 2010.  The graph on the right shows the average monthly prices between 1999 and the present.  Because the Henry Hub prices represent only those sales contracts for next day delivery, the prices can be extremely volatile.  The next graph shows the average wellhead prices since 1930.  The wellhead prices include the value of natural gas liquids and cover the wellhead prices of all gas sold under contracts of all durations.            


Higher Gas Prices Needed for Shale Gas Production

It is only in the last few years that horizontal drilling and hydraulic fracturing technologies have made the production of that natural gas in shale economically feasible.  However, because the costs of developing these unconventional wells are much higher than those for conventional wells, the incentives to produce this gas are understandably sensitive to the gas price.  Because of the differences in the permeability of the shale and the depth of the formations, the costs to produce the gas vary greatly.  A price that is high enough to justify the development of production from the Barnett Formation of Texas may not be high enough to develop production from the Marcellus Formation of Ohio, Kentucky and Tennessee, which is about a mile deep.  The Haynesville Shale of northwestern Louisiana is approximately four miles deep.  Where a conventional well might cost $1 million, an unconventional horizontal well that has been developed in the same formation can easily cost $10 million.  

Though the initial production from the unconventional wells is higher than for older conventional wells that are in the same rock formations, the technology is so new that long term production data is not available.  After the initial production of that gas is in the open fissures, flow rates decline because the most of the gas is contained in tiny pore spaces within the rock and there is poor communication between them.  There is also gas in the shale’s organic matter that also releases slowly.  The combination of the high capital costs and the slow flow rates mean that the wellhead gas prices must be high to justify the investments.

As long as the gas producers know where the shale gas is located and can increase production by simply drilling more wells into the easier to develop formations whenever the gas prices are sufficiently high to make the new wells profitable, the gas prices should fluctuate between roughly $6 and $12 per MBtu, though they could spike much higher due to changes in the supply-demand balance caused by cold weather or other factors. 

Subsidies from Electricity Produced by Gulf Stream Turbines Will be Much Larger

On February 17, 2009, President Obama extended the Production Tax Credits (PTC) and Investment Tax Credits (ITC), which have been critical to the growth of the renewable-energy sector, and added a new incentive: Treasury grants that could be taken in lieu of tax credits, designed to promote the growth of renewable energy despite the economic downturn.  The “Recovery Act of 2009” added greater flexibility to these subsidies to increase the incentives to invest in renewable energy systems.  Though the subsidies received by the owners of the Gulf Stream Turbines will be no higher than those received by the owners of the other renewable energy generating systems per kWh of electricity that is generated, because the Gulf Steam Turbines will have much higher capacity factors they will produce much more electricity.   

Production Tax Credits

Companies that generate electricity from wind, solar, geothermal, hydrokinetic (water currents), and “closed-loop” bioenergy that use dedicated energy crops are eligible for a production tax credits (PTC) that provides a 2.1-cent per kWh benefit for the first ten years of a renewable energy facility's operation.  Because the Gulf Stream Turbines’ capacity factors will be 2 to 6 times higher than those for the wind, wave, and tidal-powered renewable energy systems, the revenues produced from the 2.1 cent PTC will also be 2 to 6 times greater.          

Returns on Investments with Various Electricity Prices

The next graph shows how the returns from investments in a Gulf Stream Turbine vary with the wholesale price of the electricity.  The table on the right gives the percentages of returns on investments from the sale of the electricity at prices from zero to 21 cents per kWh and from the 2.1 cent PTC.  They are based on capital costs of $2,000 and $2,500 per kW of generating capacity.   Amazingly, because the Gulf Stream Turbines’ capacity factors would be so much higher than those of the wind turbines, just the tax credits alone would produce a rate of return of 7.82%.        


The next four graphs are similar to the preceding graph, except they are for wind turbines that cost $2,000 per kW of capacity that have capacity factors of 15%, 25%, 37%, and 45%.  The 15% capacity factor would be about the best that should be expected from wind turbines in Florida; the 25% capacity factor would be about average for all wind turbines; the 37% capacity factor is about the highest for wind turbines on land, and the capacity factor of 45% is the highest achieved by wind turbines that are offshore.   



These preceding four graphs clearly demonstrate that, when evaluating profit-earning potentials of renewable energy systems, the capacity factors can far more important than the capital costs per kilowatt of generating capacity.  For a Gulf Stream Turbine that has an 85% capacity factor to have the same amortization costs per kWh as a wind turbine with a 25% capacity factor that cost $2,000 per kilowatt of capacity, the Gulf Stream Turbine would need to cost $6,800 per kilowatt of capacity.  For the Gulf Stream Turbine to have the same amortization cost per kWh as the wind turbine that has the 15% capacity factor, the Gulf Stream Turbine’s cost per kilowatt would need to be $8,500. 

Large Additional Income Possible from the Sale of Carbon Permits

To help curb global warming, the federal government has set a goal to reduce the emissions of carbon dioxide by 17% by 2020.  Under a cap-and-trade program, those industries that emit CO2 at levels that exceed a certain level or cap would either have to buy carbon permits from those greener industries that do not need all of the permits that they are issued.   The sale of the carbon permits would be handled through an organized exchange, similar to the trading of stocks and commodities. Because the prices per ton of CO2 would be determined by auction, they would be determined by supply and demand.   Over time the carbon limits would be lowered to allow less and less emissions, until the ultimate reduction goal is met.  

Economists Joseph Aldy and William Pizer performed a study on behalf of the Pew Center on Global Climate that assumed a carbon allowance price of $15 per ton under a greenhouse gas emissions cap.  Other economists have estimated that the carbon prices would range between $20 and $40 per ton.  The present European carbon commodity futures price for January 2011 was US $30 a ton.  At that price, the owners of a 1.2 MW Gulf Stream Turbine could receive an additional $390,000 per year, based on the 13,000 tons of carbon dioxide that a coal plant would emit to produce the same amount of electricity that the Gulf Stream Turbine would generate in a year.  Though the additional revenues from the sale of the carbon permits could be substantial, it is not possible to predict what they will be because that will depend on the legislation, the law of supply and demand, and on the aggressiveness of those administering the program to reach the stated goal of a 17% reduction in CO2 emissions by 2020.  On October 22, 2009 the Wall Street Journal printed the following by Senator Kirsten Gillibrand (Dem. NY): 

“According to financial experts, carbon permits could quickly become the world’s largest commodities market, growing to as much as $3 trillion by 2020 from just over $30 billion today.   With thousands of firms and energy producers buying and selling permits to emit carbon, transaction fees for exchanges and clearing alone could top nearly half a billion dollars. 

If Congress establishes proper oversight of a carbon market, New York’s financial talent, expertise and institution and uniquely suited to provide the tools and innovation for a new commodities market of this size….

An infrastructure is already beginning to form, as entities like the New York Stock Exchange, J.P. Morgan Chase, Goldman Sachs, and the new Green Exchange are developing carbon trading platforms or expanding their environmental trading desks.  There are nearly 100 funds already focused on green investment….”

Investors can play the carbon market by either investing in the carbon credits themselves, or by investing in those companies that will be increasing their profits from selling those credits they don’t need.  Because the Gulf Stream Turbines will emit absolutely zero carbon dioxide and operate with high capacity factors, they well earn from 2 to 6 times as many salable carbon permits than those renewable system that rely on the kinetic energy of the winds or tides, or the radiant energy from the sun – in terms of both the number of permits issued per kilowatt of generating capacity and per dollar invested.  

In the earlier section entitled Mind Boggling Environmental Benefits we stated that a Gulf Stream Turbine, equipped with two 600-kW generators and operating at an 85% capacity factor, would generate 8,941,300 kWh of electricity per year.  We also stated that to replace that same amount of electricity that was presently being generated with a coal plant would reduce the carbon dioxide emissions by about 13,000 tons.  If the price of the carbon permits were at the $30 per ton, which happens to be the European carbon commodity futures price for January 2011, the owners of a 1.2-megawatt Gulf Stream Turbine could conceivably receive an additional $390,000 from the sale unneeded carbon permits to those generating electricity with coal.  That additional income would increase the return on a Gulf Stream Turbine that cost $2,000 per kW by an additional 16.25%.

When the various revenues that can be generated by the Gulf Stream Turbine are combined, the results become impressive.  For example, if that $390,000 from the sale of the carbon offsets were to be added to revenues of $894,130 that would be received from the sale of the 8,941,300 kWh at 10 cents per kWh, and the 2.1 cent per kWh hour production tax credit, the total revenues would come to $1,471,887 per year, which be a return of 73.6% on an investment cost of $2,000 per kW, and a return of 58.9% if it were $2,500. 

(Due to the serious economic recession and an increasing skepticism concerning man’s part in causing climate change, there is now little possibility that any cap-and-trade legislation will soon be passed by Congress.)  




Gulf Stream Power Can Help Solve Florida’s Water Woes

Why Florida is Vulnerable to Drought

Beginning in 1998, Florida began to experience a range of regional water problems that were caused by a three-year drought.  This drought, along with the increasing needs of the growing population and the heavy water use for agriculture, resulted in a heavy drawdown of the groundwater.  This adversely affected the natural wetlands and lakes of central and southern Florida, leading to salinity intrusion.  Though the rains returned during the summer of 2001 to replenish the lakes and rivers, the overdrawn aquifers have not recovered. 

Florida's aquifers vary in depth, composition, and location, and they are divided into two general categories: the surficial and the Floridan.  The surficial aquifers are shallow beds of shells and sand that lie less than 100 feet underground.  They are separated from the much deeper Floridan aquifer by a confining bed of soil. Even though some of the surficial aquifers have been contaminated by saltwater intrusions, they provide most of the freshwater to the areas to southwest of Lake Okeechobee and along the Atlantic coast north of Palm Beach. 

The most important of the surficial aquifers is the Biscayne aquifer, which covers 3,000 square miles in southeast Florida.  This is the most intensely used water source in Florida, supplying water to Dade, Broward, Palm Beach, and Monroe counties. Because this aquifer it is near the surface, it is vulnerable to pollutants that leach down through the shallow limestone bedrock. In some areas, the groundwater has been contaminated by fuel spills, industrial discharge, landfills, and saltwater.  Due to excessive pumping, the aquifer’s water-table remains low, making the heavily populated area vulnerable to severe water shortages.           

The Chokoloskee aquifer is yet another on of Florida’s shallow surficial aquifers.  It covers 3,000 square miles in southwest Florida and is recharged by rainfall.  Artificial drainage canals have lowered water levels and increased saltwater intrusion.  

The much deeper Floridian aquifer is a portion of a much larger artesian aquifer that extends into the Florida.  It is the largest, oldest, and deepest aquifer in the southeastern US, ranging over Alabama, southeastern Georgia, and southern South Carolina.  The Floridian portion of the principal aquifer developed millions of years ago, when Florida was underwater.  Due to the heavy dependence on the shallower surficial aquifers that have had falling water-tables and on the surface water of the lakes and streams that went dry, serious water shortages have occurred in recent years throughout much of the state.  Current trends in development within northeast Florida have increased the demand placed on the Floridian aquifer system. To meet the needs of the public, increasing amounts of water are being pumped from it.  The U.S. Geologic Survey has estimated that the water levels within the Floridian Aquifer system in Duval County are declining at the rate of 0.3 to 0.75-feet per year due to the increased demand. The aquifer’s lower water levels increase the risk of contamination from both surface and subsurface pollution. Additionally, the lower water levels also increase the risks of saltwater intrusion.  

Drought Caused Water Management to Consider Alternative Water Sources

It was because of the three-year drought of 1998-2001 that the utilities, local governments, and water management districts began making plans to develop alternative water sources to ensure that the future demands for drinking water can be met.  These plans have included the building reservoirs, drilling deep wells to store water for dry times, expanding the use of treated sewage water for lawns, and the desalination of seawater.  The West Coast Regional Water Supply Authority (later to become Tampa Bay Water) chose desalination because it was the only alternative water source being considered that would not be adversely affected by drought.  This decision resulted in the construction of the largest desalination plant in the United States at Tampa Bay.  

Though this plant was designed to have a maximum capacity of 25 million gallons a day, the plan was to have it produce only 15 million gallons a day – enough to provide about 10% of Pinellas Hillsborough, and Pasco counties’ drinking water, with the rest of the water to come from a surface water treatment plant in Brandon.  However, the Brandon plant was forced to shut down in March 2009 because of lack of water.  Low rivers in the area, coupled with the depletion of the 15-billion-gallon reservoir, rendered the plant useless until the rainy season returned that summer.  In the meantime, the desalination plant and the company’s underground aquifer were strained to meet the area’s water needs. 

Gulf Stream Turbines Can Supply Low-Cost Energy for Desalination

The following diagram is reproduced from the website of the World Business Council for Sustainable Development.  It was contained in a paper entitled Water, Energy and Climate Change.  It shows the kilowatt-hours of electricity required to produce one cubic meter of drinking water from those sources that are listed.  The diagram was amended by WBCSD from an article that appeared in Scientific American in October of 2008. 

The desalination of seawater requires extremely large amounts of energy, making the desalinated water costly compared to costs of fresh water from rivers and groundwater.  It is because of the very high water pressures that are required by the reverse osmosis technology to push the water through the semi-permeable membranes that separate the salts from the seawater that the costs of the per cubic meter of the produced fresh water are high and extremely sensitive to the costs of the energy used. 

When Florida began to study the feasibility of building large-scale desalination plants, there were originally 23 potential plant sites that were considered that stretched along South Florida’s east coast from Fort Pierce to Miami.  These sites were since reduced to Fort Lauderdale, Port Everglades, Miami, and Fort Myers.  With the exception of Fort Myers, which is on Florida’s west coast, the others sites would be superb locations for desalination plants powered by the Gulf Stream’s “free” hydrokinetic energy that is offshore.    


Thermal Power Plants Consume Large Quantities of Water for Cooling

The Gulf Stream Turbines can also help Florida’s fresh water supply saving that fresh water that would otherwise be used in the thermal power plants for evaporation cooling.   

According to the second law of thermodynamics, not all of the thermal energy produced by a boiler can be transformed into mechanical power.  Consequently, all thermal power plants produce waste heat energy as a byproduct of the useful electrical energy that they produce. The amount of the waste heat energy normally exceeds the amount contained in the electrical energy that the plants produce.  Natural draft wet cooling towers at nuclear and large fuel-fired power plants use large hyperbolic chimney-like structures that release the waste heat to the ambient atmosphere by the evaporation of fresh water to condense the spent steam back into liquid form that can then be reheated to produce more high-pressure steam.     

Of the potential desalination sites in South Florida, all are located where the surficial aquifers are already seriously overdrawn.  Producing electricity with the Gulf Stream Turbines would eliminate any need for the water-consuming cooling towers.  

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Condensing water vapor coming from nuclear plant’s cooling towers

In areas with restricted water use a dry cooling tower or radiator that is directly air cooled may be necessary when the costs or environmental consequences of obtaining make-up water for evaporative cooling would be prohibitive. These air cooled systems have much lower efficiencies and higher energy consumption than the evaporating cooled systems, due largely to the power used by the fans to blow huge volumes of air through the dry cooling towers. 

Unlike the thermal power plants that are powered by steam produced by boiling water, the Gulf Stream Turbines are powered by the “free” hydrokinetic energy contained in the constantly flowing Gulf Stream, and unlike the thermal power plants, the Gulf Stream Turbines will require no freshwater for cooling and cause no noticeable heating of the environment.



“Greetings from Taiwan

On April 5, 2009, I received an e-mail from Professor Falin Chen.  He is a university professor at the National Taiwan University and he is in charge of planning the research for Taiwan’s National Energy Program, a multi-billion US dollar, five-year project.  A major part of this program is the harnessing of the kinetic energy contained in the Kuroshio, the Pacific Ocean’s equivalent to the Gulf Stream.  After reading the Gulf Stream Turbine website, he concluded that my design would be one of the best that they could choose for Taiwan’s Kuroshio Power Plant (KPP) project. 

In a subsequent e-mail, Professor Chen stated that he had read my website several times and was impressed that my design was based on such “practical thinking”.   He had taken four separate trips around the world to see the different turbine designs that were being developed for ocean currents and that the Gulf Stream Turbine was the best that he had seen.  

            (Though the Kuroshio is comparable to the Gulf Stream where it flows past the southern tip of the Izu Peninsula, southwest of Tokyo, where it passes along the east coast of Taiwan, the water is deeper and the current is both wider and slower, traveling at an average speed of about 1.2 meters per second (2.6844 mph) during the summer and only about 0.9 meters per second (2.0133 mph) during the winter.  Because of the slowness of the Kuroshio near Taiwan would increase the cost per kilowatt of capacity, I decided not to divert my attention away from the getting the machines licensed and in the faster Gulf Stream.) 



Gas Saved by Gulf Stream Turbines Can Reduce Oil Imports

Not only can the Gulf Stream Turbines produce large reductions in the emissions of CO2, they can also reduce our nation’s dependence on foreign oil.  Though only 1.1% of the electricity in the U.S. is generated with oil, by reducing the amount of natural gas that is consumed to produce electricity could make more gas available for other purposes.  The plan proposed by T. Boone Pickens would use wind turbines to replace that gas, which could then be used as fuel for vehicles.  Since the capacity factors of the Gulf Stream Turbines would be much higher than those of the wind turbines, they would be able to produce much more electricity and free-up much more natural gas. 

Paradoxically, the widespread use of wind turbines could actually increase the consumption of natural gas to produce electricity.  This is because the wind turbines would be mostly distributed through the central plains states that are colored red and orange in the following map, where most of the electricity is being produced by coal plants.  The reason the increases in the wind turbines could cause an increase the consumption of natural gas for power generation is that the winds are intermittent, and it is only the gas-fired turbine plants that can be quickly brought on line to cover the load when the winds stop blowing.  As a result, an increase in the number of wind turbines will also require in the number of gas turbines to provide needed standby capacity.  The consumption of natural gas for power generation will increase if the wind and gas turbines start to replace the base-load electricity being produced by the coal-fired plants.   Though the amount of gas consumed for to generate electricity may not decrease, there should be a reduction in the emission of greenhouse gases.


A better plan, and one proposed by a growing number of groups is to electrify our transportation system.  Instead of converting part of our transportation system to natural gas, only to later have to convert it back to renewable fuels, we should start now to convert the transportation system to electricity and hydrogen and produce the electricity and hydrogen from renewable and nuclear energy.  Whether the Gulf Stream Turbines produce electricity to replaces the natural gas that would power vehicles, or would produce electricity that is used to charge the batteries of plug-in hybrids, electric, or to produce hydrogen for fuel-cell-powered cars, that electricity would replace imported oil.  

The U.S. consumes approximately 19.5 million barrels of oil per day.  There are 42 gallons per barrel and each barrel contains approximately 5.8 million Btu.  If a Gulf Stream Turbine, with a generating capacity of 1.2 MW, were to operate with a capacity factor of 85%, it would generate 8,941,300 kWh of electricity per year.  To generate that electricity with the most efficient gas-fired turbines would consume approximately 52,650 million Btu of gas.  If you divide those Btu by the 5.8 million Btu in a barrel of oil, we find that each Gulf Stream Turbine would reduce the consumption of fossil fuel by the equivalent of 9,077.6 barrels (381,259 gallons) of oil per year.  Then thousand of those turbines would reduce it by the equivalent of 90,776,000 barrels per year, which would be 248,701 barrels per day.



Gulf Stream Turbines Should Be Produced in Huge Numbers

The Gulf Stream Turbines, operating in the central axis of the Gulf Stream off the coast of South Florida, can generate incredible amounts of steady, low-cost electric power while consuming no fuel or producing any pollutants.  This website has explained why there is a need for thousands of these machines and why those who will own and operate them can expect returns of between 24% and 86%, depending on costs of that electricity produced by the gas turbines – and that’s not counting any additional income that might come from the sale of carbon permits under a cap-and-trade program.  It is because of these high returns from the investments in these unique machines that the company that acquires the exclusive rights to manufacture them would be able to sell them as fast as they can be produced with exceptional profit margins.     

During World War II, the Ford Motor Company built a giant plant at Willow Run, Michigan that mass-produced the B-24 Liberator bomber.  Each of these aircraft had 488,193 parts, 230,000 components, and 24 major subassemblies.  Yet, because the need was urgent, through ingenuity, perseverance and productivity, they managed to reach a peak production level of 25 units per day.  The need for these submersible power plants is equally as great.  However, unlike the B-24 bombers, these machines – though large – are mechanically very simple.




The Inventor and Chairman: John Robson          

John Robson was raised in Winnetka, Illinois.  Since he was about ten years old, he has been interested in airplanes and could accurately draw many of them from memory.  John flew for the first time when he was 16.  It was a Piper Cub and, within a half-hour, he was doing stalls and spins over farmland that is now Buffalo Grove, Illinois. 

When he was in eighth grade he had a teacher who motivated a previously lazy student to enjoy math.  It was because of this teacher that John discovered that he had an ability to quickly write the algebraic equations for solving complicated problems.  It was also because of her that John got top grades in both Algebra and Physics at New Trier High School.  During his first year at Iowa State, he received perfect scores on every test in Physics – except for one question that he missed on the final exam. 

After receiving his Bachelor of Science Degree in Agriculture, John served two years as a personnel officer at Luke AFB, Glendale, Arizona.  After leaving the Service, he returned to Illinois to operate the family farm, which, under his management, became the largest dairy farm in Illinois in terms of volume of milk produced, producing over 9,000 pounds of milk a day. 

While John was operating the farm, he invented a variable-speed conveyor that allowed trucks to quickly dump their loads of chopped forage onto a movable apron that could move at widely varying speeds. The machine allowed dump trucks to unload as quickly as their hoists could raise their dump bodies. Not only did the invention permit the trucks to immediately unloaded so that they could return to the field, its variable-speed apron also permitted the material to be transferred to the silo filling machine at a rate that matched the silo filling machine's maximum capacity. John had not planned on patenting his variable-speed conveyor until a representative from a farm equipment company saw it operate and urged him to do so. It is US Patent No. 3,370,695.  

After the farm was sold, John went into the retail fuel business with his two older brothers.  During the 1970s and early 1980s, John served eight terms as the president of the Oil Heat Marketers Association, a trade association that represented retail fuel oil marketers in northeastern Illinois.  In September of 1973, soon after he became the association’s president, he went to Washington to meet with former governor of Colorado, John A. Love, who was beginning to serve as the first Director of the Office of Energy Policy in President Nixon’s administration.  During their meeting John presented Love with information about the interlocking relationships that existed between the different fuels and how the policies that affected one fuel would affect others.  He also described how the government’s disjointed pricing and curtailment policies for natural gas and for petroleum fuels were causing serious problems because they were just the reverse.  At the conclusion of the meeting, Love told John that it was very important that he testify before the hearings of the Senate Commerce Committee that were being scheduled for October 24-25, 1973. 

The paper that John presented at that hearing described how the government’s policy of controlling the interstate natural gas prices had not only discouraged investments to increase the production of natural gas and encouraged its wasteful use, but that had also discouraged the investments to increase the production of all the other sources of energy.  After Representative John Rousselot (R. CA) read John’s paper, he made a short speech about it before Congress and had it printed in the Congressional Record (Dec 4, 1973).  He then had John’s paper reproduced from the Congressional Record and mailed to all of his constituents.  A few weeks after that Senate hearing, the CEO of Mobil Oil, “Wally” Warner, had two of his men call on John at his office to ask permission to reprint the essence of John’s paper in the informational “ads” that Mobil was running to educate the public about the need for the government to end its short-sighted and disjointed energy policies.

Later John developed a relationship of mutual respect with Dr. William A Johnson, an economist whom William E. Simon had brought to the then new Federal Energy Administration from the Treasury Department. It was through Dr. Johnson that John managed to get the FEA to stop allocating naphtha (raw gasoline) and other light petroleum feedstock to the gas utilities which they were converting into synthetic natural gas (and losing 10% of the fuel’s heat content in the process).  The gas companies were then mixing their very expensive synthetic gas with their much larger volumes of the artificially cheap price-controlled natural gas and then used the mixed gas to convert more residential oil customers to gas.  John did not realized that he had been the one to cause the end of the allocations of the naphtha to the synthetic gas plants until “Bud” Lawrence, the Executive Director of the American Gas Association, told him that he had attended a meeting in which Dr. Johnson had repeated my arguments almost verbatim and that he had been adamant about ending the allocations.           

As the result of the earlier statement that John had presented at the Senate Commerce Committee’s hearing, he was asked to serve as the Chairman of the Natural Gas Task for of the National Oil Jobbers Council (later to be renamed as the Independent Petroleum Marketers Association).  He did all of his own research for the papers that he wrote for the testimonies that he presented to congressional committees and federal and state commissions.  He was also asked to serve as a member of the Natural Gas Transmission and Distribution Advisory Committee of the FEA and the DOE, was appointed to the Natural Gas Supply Committee of the Federal Power Commission (which never met), and served as a member of the Energy Efficiency of Buildings in Cities Advisory Panel for the Office of Technology Assessment (1982) of the 97th Congress.  In addition to representing the members of the National Oil Jobbers Council, the Illinois Petroleum Association, the Oil Heat Marketers Association, on two occasions John was asked by the National Federation of Independent Business (he was a member) to represent that organization at meetings with the Department of Commerce. 

It was Dr. M. King Hubbert, probably the best known geophysicist in the world for his 1949 prediction that the fossil fuel era would be of very short duration, who convinced John that the United States was heading toward worsening shortages of both oil and natural gas due to depletion.  It was in the late 1990s, after John had seen a slide program about wind turbines that he started thinking about designing a turbine system that would be powered by the constantly flowing kinetic energy of the Gulf Stream rather than the intermittent winds.  From the very inception of his invention, John’s goal has been to design a machine that would be very efficient, extremely reliable, and elegantly simple. 

John Robson  

December 13, 2009




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