Abstract:
A subsurface power generating system in one embodiment includes a frame, an electric generator supported by the frame and operably connected to a first vertical rotor, another electric generator supported by the frame and operably connected to a second vertical rotor, a first louver operably connected to the first vertical rotor and including a front side, and a back side, and pivotable between a first position whereat the backside is in contact with a first pivot limiting structure, and a second position whereat the backside is not in contact with the first pivot limiting structure, and a second louver operably connected to the second vertical rotor and including a front side, and a back side, and pivotable between a third position whereat the backside is in contact with a second pivot limiting structure, and a fourth position whereat the backside is not in contact with the second pivot limiting structure.

Description:
This application is a divisional application of U.S. patent application Ser. No. 11/519,607, filed Sep. 12, 2006, which claims the benefit of provisional U.S. patent Application Ser. No. 60/716,063, filed on Sep. 12, 2005. 
    
    
     FIELD 
     The present invention relates generally to the field of hydroelectric power generation, and, more particularly, to an apparatus and method for generating electric power from a subsurface water current. 
     BACKGROUND 
     The wealth of the United States has been created largely through the exploitation of cheap energy provided by the past abundance of fossil fuels. Because of the increasing shortages of natural gas in North America, the continued reliance on oil suppliers located volatile regions, the approaching worldwide shortages of oil, and because of the growing danger of global warming that may be caused by the combustion of fossil fuels, clean reliable sources of renewable energy are needed. 
     Many of the efforts to develop power generation systems fueled by renewable energy sources have been focused on wind energy. Although wind powered generating systems provide many benefits, they have a significant drawback. Specifically, wind direction and speed are in a constant state of flux. Wind speeds can fluctuate hourly and have marked seasonal and diurnal patterns. They also frequently produce the most power when the demand for that power is at its lowest. This is known in the electricity trade as a low capacity factor. Low capacity factors, and still lower dependable on-peak capacity factors, are notable shortcomings of wind power generation. 
     In contrast to the winds, some deep ocean currents are driven largely by relatively steady Coriolis forces. The fact that such ocean currents are not subject to significant changes in direction or velocity makes sub-sea power generation somewhat more desirable than the intermittent power produced by wind-driven turbines. The book, Ocean Passages of the World (published by the Hydrographic Department of the British Admiralty, 1950), lists 14 currents that exceed 3 knots (3.45 mph), a few of which are in the open ocean. The Gulf Stream and the Kuro Shio are the only two currents the book lists having velocities above 3 knots that flow throughout the year. Both of these currents are driven by the Coriolis force that is caused by the Earth&#39;s eastward rotation acting upon ocean currents produced by surface trade winds. Because these currents are caused largely by the Earth&#39;s rotation, they should remain constant for a substantial period barring significant changes in local geography. 
     The Gulf Stream starts roughly in the area where the Gulf of Mexico narrows to form a channel between Cuba and the Florida Keys. From there the current flows to the northeast through the Straits of Florida, between the mainland of the United States and the Bahamas, flowing at a substantial speed for some 400 miles. The peak velocity of the Gulf Stream is achieved off of the coast of Miami, Fla., where the Gulf Stream is about 45 miles wide and 1,500 feet deep. There, the current reaches speeds of as much as 6.9 miles per hour at a location between Key Largo, Fla. and North Palm Beach, Fla., and less than 18 miles from shore. Farther along it is joined by the Antilles Current, coming up from the southeast, and the merging flow, broader and moving more slowly, continues northward and then northeastwardly, as it roughly parallels the 100-fathom curve as far as Cape Hatteras, N.C. 
     The Kuro Shio is the Pacific Ocean&#39;s equivalent to the Gulf Stream. A large part of the water of the North Equatorial current turns northeastward east of Luzon and passes the east coast of Taiwan to form this current. South of Japan, the Kuro Shio flows in a northeasterly direction, parallel to the Japanese islands, of Kyushu, Shikoku, and Honshu. According to Ocean Passages of the World, the top speed of the Kuro Shio is about the same as that of the Gulf Stream. The Gulf Stream&#39;s top flow rate is 156.5 statute miles per day (6.52 mph) and the Kuro Shio&#39;s is 153 statute miles per day (6.375 mph). 
     Other possible sites for the underwater generators are the East Australian Coast current, which flows at a top rate of 110.47 statute miles per day (4.6 mph), and the Agulhas current off the southern tip of South Africa, which flows at a top rate of 139.2 statute miles per day (5.8 mph). Another possible site for these generators is the Strait of Messina, the narrow opening that separates the island of Sicily from Italy, where the current&#39;s steady counter-clockwise rotation is produced primarily by changing water densities resulting from evaporation in the Mediterranean. Oceanographic current data may suggest other potential sites. 
     Submersible turbine generating systems can be designed to efficiently produce power from currents flowing as slowly as 3 mph—if that flow rate is consistent—by increasing the size of the turbines in relation to the size of the generators, and by adding more gearing to increase the shaft speeds to the generators. Because the Coriolis currents can be very steady, capacity factors of between 70 percent and 95 percent may be achievable. This compares to historical capacity factors for well-located wind machines of between 23 percent and 30 percent. Because a well-placed submersible water turbine will operate in a current having even flow rates, it may possible for it to produce usable current practically one hundred percent of the time. 
     Moreover, increasing human ingress into the oceans makes undersea power generation desirable. Historically, submarines have had to periodically surface and dock at shore based ports for maintenance that has included recharging or replacing electric batteries and/or receiving temporary electric power during the maintenance of their on-board generators. Such needs to periodically travel to shore based facilities have undesirably limited the mission capabilities of many submarines. A suitable deep sea power generation facility could provide opportunities for submarines to obtain electric power for maintenance while remaining submerged and without diversion from the open ocean to a shore location. Additionally, as the number of underwater scientific observatories increases, so does the need to generate power for the observatories at the observatory sites. Further, whether engaged in military, scientific, commercial, or recreational activities humans need potable water. Potable water can be produced from sea water, but such production facilities typically require electricity. 
     Although the needs are numerous, viable sub-sea power generation has presented notable challenges. For example, rotating electric generators produce heat. The electric current flowing through the conductors, both in the stator and rotor, produces heat because of the electrical resistance. In addition, heat is generated in the steel of the rotor armature core by the changing magnetic fluxes and bearing, shaft, and gear friction produces heat as well. Although the heat loss in large generators is typically only on the order of about 1 percent of output, this is still considerable. For example, a pair of generators producing 1,200 kW might have a loss of 12 kW, which is equivalent to 40,973 BTU per hour. Therefore, a liquid cooling system is desirable for dissipation of heat produced by a sub-sea power generation system. Additionally, maintaining proper horizontal, vertical, and azimuthal turbine positioning relative to ocean current depths and directions for optimizing capacity factors in operation of sub-sea power generation systems has been challenging. Another challenge has been that deeply submerging power generation units has made them less readily accessible for servicing and repair. 
     SUMMARY 
     A subsurface power generating system in one embodiment includes a frame, a first electric generator supported by the frame and operably connected to a first vertical rotor, a second electric generator supported by the frame and operably connected to a second vertical rotor, a first louver operably connected to the first vertical rotor and including a front side, and a back side, and pivotable between a first position whereat the backside is in contact with a first pivot limiting structure, and a second position whereat the backside is not in contact with the first pivot limiting structure, and a second louver operably connected to the second vertical rotor and including a front side, and a back side, and pivotable between a third position whereat the backside is in contact with a second pivot limiting structure, and a fourth position whereat the backside is not in contact with the second pivot limiting structure. 
     In another embodiment, a method of generating electrical power from a water current includes positioning a first louver within a water current, impinging a front side of the first louver with the water current, pivoting the first louver into contact with a first pivot limiting structure using a first force generated by the impinging water current, transferring a second force from the water current to the first pivot limiting structure, and rotating a first vertical rotor operably connected to a first electrical generator with the transferred second force. 
     In a further embodiment, a subsurface power generating system includes a frame, a first electric generator supported by the frame, the first electric generator operably connected to a first vertical rotor, a first louver operably connected to the first vertical rotor and including a front portion, and a back portion, and pivotable between a first position whereat the back portion is in contact with a first pivot limiting structure, and a second position whereat the back portion is not in contact with the first pivot limiting structure, and a first bar extending through the first louver and defining an axis of rotation for the first louver such that the first louver is cantilevered toward the second position from the first position in response to a current contacting the back portion of the first louver and cantilevered toward the first position from the second position in response to the current contacting the front portion of the louver. 
     The above-noted features and advantages of the present invention, as well as additional features and advantages, will be readily apparent to those skilled in the art upon reference to the following detailed description and the accompanying drawings, which include a disclosure of the best mode of making and using the invention presently contemplated. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective view of an exemplary manned subsurface electric power generation station in accordance with principles of the present invention; 
         FIG. 2  shows a partial cutaway view of a generating node of the station of  FIG. 1  showing a number of modular generators coupled to a plurality of universal gears through individually controllable clutch mechanisms; 
         FIG. 3  shows schematic view of an anchoring and positioning system used with an alternative manned subsurface electric power generation station in accordance with principles of the present invention; 
         FIG. 4  shows a schematic view of a control network for the various subsystems of the manned station of  FIG. 1  in accordance with principles of the present invention; 
         FIG. 5  shows a top plan view of the station of  FIG. 1 ; 
         FIG. 6  is a partial cutaway view of the station of  FIG. 1  showing additional detail of the power generating node of  FIG. 2 ; 
         FIG. 7  shows a schematic of the placement of crossbars with the louvers used in the louver panels of the station of  FIG. 1  which reduce the need for maintenance on the louvers; and 
         FIG. 8  shows a partial cutaway view of the dry transfer node and elevator system of the station of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Like reference numerals refer to like parts throughout the following description, the accompanying drawings, and the claims. 
       FIG. 1  shows a perspective view of an exemplary sub-sea electric power generation station  100  according to the present invention. The station  100  is designed to operate 24 hours per day and 365 days per year while totally submerged to supply power to an onshore power grid through an umbilical (not shown). The station  100  is marine creature, biomass, and navigational friendly, and is suitable for, among other locations, geographic locations where fairly constant, vector specific sub sea currents are present. It should be appreciated that there are numerous worldwide locations (e.g., North American Gulf Stream areas such as the Florida, Georgia, and South Carolina coasts, among others) where constant, vector specific, sub-sea currents can be harnessed to generate electricity. In addition to the ability to generate electrical energy, the station  100  is capable of producing significant quantities of potable water. 
     The station  100  includes a neutrally buoyant, manned, one atmosphere, frame  102 . The frame  102  includes a generally horizontally oriented upper triangularly shaped pressure resistant structure  104 , a generally horizontally oriented lower triangularly shaped pressure resistant structure  106 , and three substantially hollow generally vertically oriented legs or “spars” (a first spar  108 , a second spar  110 , and a third spar  112 ) extending between the structure  104  and the structure  106 . 
     The triangularly shaped structures  104  and  106  and the spars  108 ,  110  and  112  are generally cylindrical in construction and manufactured to appropriate standards such as American Society of Mechanical Engineers (ASME) standards for a pressure vessel for human occupancy (PVHO-2, section VIII, Division I), National Board, American Bureau of Shipping (ABS) and U.S. Coast Guard (USCG) standards. The frame  102  is configured to be neutrally buoyant. Neutral buoyancy may be achieved by a variety of combinations of water displacement by the station  100  and permanent and variable buoyancy including the use of “hard” and “soft” ballast tanks and syntactic foam. 
     The upper triangular structure  104  in this embodiment provides living quarters similar to those found onboard a merchant vessel including berthing quarters, restrooms, showers, common rooms, off duty rooms, food preparation and storage areas, a small infirmary, a communication and media room, an exercise area, etc. Additionally, the upper triangular structure  104  provides a storage area for emergency equipment such as an emergency escape pod and a one atmosphere absolute transfer-under-pressure (One ATATUP) module. 
     The lower triangular structure  106  provides additional space for storage and equipment. By way of example, water generators (either reverse osmosis (“R/O”) or distilling type), a sanitary station, water heaters, control equipment, fire suppression systems (“FSS”), a decompression chamber, a diver lock out compartment (“DLOC”), remote vehicle lock out ports (“ROVLOCs”), air chargers and environmental control units (“ECU”) are provided with the station  100 . The environmental control units include oxygen generators, scrubbers and burners. The lower triangular structure  106  further houses tanks for the storage of potable water, pressurized air and oxygen and one or more heat exchanger systems for thermal cooling of rotating machine parts and for using the heat generated by the machine parts to heat the station. Additionally, a battery provides a back-up power supply in case power generation is disrupted and the power grid is not available. 
     The station  100  includes six nodes. Nodes  114  and  116  are joined by the spar  110 , nodes  118  and  120  are joined by the spar  112  and nodes  122  and  124  are joined by the spar  108 . Six additional spars further join the various nodes. Specifically, along the upper structure  104  spar  126  joins nodes  122  and  114 , spar  128  joins nodes  114  and  118 , and spar  130  joins nodes  118  and  122 . Along the lower structure  106  spar  132  joins nodes  124  and  116 , spar  134  joins nodes  116  and  120 , and spar  136  joins nodes  120  and  124 . Each of the passageways between the nodes and the spars may be sealed by a watertight door (not shown) to isolate the various areas in case of flooding or other emergency. The nodes  116 ,  120  and  124  are secured to pylons  117 ,  121  and  125 , respectively. The pylons  117 ,  121  and  125  are anchored in the seafloor. 
     The spar  110  and the spar  112  serve as housings for vertical drive shafts. With reference to  FIGS. 1 and 2 , a drive shaft  138  extends between the nodes  116  and  114 . The drive shaft  138  is coupled to three louver panels  140 ,  142  and  144 . The louver panels  140 ,  142  and  144  are rotatably supported by the spar  110 . The drive shaft  138  drives a number of modular electrical generators such as modular generators  146 . The spar  112  is similarly configured with louver panels  141 ,  143  and  145 . Thus, in this embodiment each power generator node  114 ,  116 ,  118 , and  120  houses sixteen stacked modular generator units. 
     The spar  108  is outfitted with instrumentation and blade/vane microprocessors that control closing of the various louver panels such as louver panels  140 ,  141 ,  142 ,  143 ,  144  and  145  in the proper sequence to maximize the extraction of kinetic energy from the water current and controls opening of the various louver panels in order to minimize the surface resistance of the louvers that are rotating back into the “driven position.” The lower portion of this instrumentation spar  108  also provides a one-atmosphere scientific observation station. 
       FIG. 3  shows an alternative station  300  with various components removed to more clearly show an anchoring and positioning system  150 . The anchoring and positioning system  150  includes a massive circular “mud pad” type anchor  152  that is buried in the seafloor  154  using high-pressure water jets as is known to those of ordinary skill in the relevant art. 
     The system  150  further includes three stainless steel “tension leg” cables  156 ,  158  and  160  which extend from the mud pad  152  and are held in tension by respective redundant, syntactic foam filled, stainless steel subsurface buoys  162 ,  164  and  166 . The length of the cables  156 ,  158  and  160  is selected such that the subsurface buoys  162 ,  164  and  166  are not maintained at a depth to pose a significant impediments to surface going vessels (under power or tow) in any sea state. Alternatively, the station  300  may be located in an area where fishing and navigation are restricted to avoid entanglement or damage. Each individual stainless steel tension leg cable  162 ,  164  and  166  passes through the corresponding vertical spar  310 ,  308  or  312  of the station  300 . The cables  162 ,  164  and  166  of the system  150  are equipped with emergency buoyancy devices so any portions of damaged/fouled cable will float to the surface rather than sink and potentially entangle in the louver panels. 
     The anchoring and positioning system  150  further includes large spool winches and/or other suitable hydraulic traction devices (not shown) located inside each of the respective spars  308 ,  310  and  312 . The anchoring and positioning system  150  submerges the station  300  to the selected operational depth by employing the winches to draw in cable and pull the station  300  toward the sea floor  154 . Conversely, the winches may also be used to allow the station  300  to “crawl” from the selected operational depth up to the tension leg buoys  162 ,  164  and  166 . The variable ballast tanks may be used to provide the station  300  with negative or positive buoyancy to reduce the load on the winches during these operations. 
     Additionally, the anchoring and positioning system  150  can rapidly semi-surface the station  300  to a shallow depth by releasing the cables  156 ,  158  and  160  and using the variable ballast tanks to provide a positive buoyancy. In either event, the station  300  may be positioned to just below the surface  168  of the ocean where it can be serviced by conventional diving equipment. 
     The station  300  also includes a tethered one-atmosphere “elevator” pod  170  that can be surfaced and submerged from the station  300  by releasing or retracting a cable from a cable winch mounted on the station  300 . The pod  170  can be used for transporting equipment from the surface  168  to the submerged station  300 . The pod cable is equipped with emergency buoyancy devices so any portions of damaged/fouled cable will float to the surface rather than sink and potentially entangle in the panels louver panels. 
     Returning to  FIG. 1 , the station  100  is further configured to produce large quantities of potable water. In addition to employing the louver panels to generate electric power, the system employs either generated electrical power or the mechanical force of the rotating louver panels  140 ,  141 ,  142 ,  143 ,  144  and  145  to power high pressure water pumps that pull in ambient sea water  660  through marine biology friendly (suction break) filters and to force the high pressure sea water through a reverse osmosis membrane to produce fresh potable water. Alternatively, the sea water may be distilled. If needed, the potable water may be micro gas chlorinated. The potable water is then available for consumption on station  100  during manned operations and/or may be pumped to a mainland water facility via buried pipelines. 
     The station  100  further includes a brine diffusion system, a holding tank that collects the brine (“flush”) of the reverse osmosis process, and a pump that injects the brine into the brine diffusion system. The brine diffusion system includes long runs of perforated pipe and a pump that forces a strong flow of ambient seawater through the pipe. The system  400  injects the brine solution into the pipes in metered doses and the brine then diffuses into the surrounding sea water through the perforated piping in a controlled manner so as to not salt poison marine life. This ameliorates undesirable production of salt clouds in the water column that could be poisonous to marine life. Preferably, the brine diffusion piping is located downstream from the station  100 . 
     Operations of the station  100  are controlled through a station computer network  170  shown in  FIG. 4 . The network  170  includes a user interface  172 , a microprocessor  174  and a memory  176 . The microprocessor  174  is programmed to monitor and control various functions related to the operation of the station  100 . By way of example, various sensors  178  associated with the production of power may be monitored. The sensors  178  in this embodiment include sensors that produce outputs corresponding to the rotational position of the louver panels  140 ,  141 ,  142 ,  143 ,  144  and  145 . 
     The microprocessor  174  also monitors environmental conditions through sensors  180  including atmospheric conditions within the station  100 . The sensors  182  provide signals corresponding to conditions upstream of the station  100 . The sensors  182  in this embodiment are AQUADOPP® current meters commercially available from NortekUSA of Annapolis, Md. The sensors  182  provide outputs indicative of water temperature and water velocity. The sensors  182  are located in the current path upstream of the station  100 . 
     The microprocessor  74  is further programmed to provide various control functions. By way of example, the microprocessor  174  provides control signals to various systems  184  used to maintain the environment of the station  100  habitable. The systems  184  include the heating, ventilation and air conditioning systems. The microprocessor further controls the machinery associated with fire suppression systems  186 , communication systems  188 , and auxiliary systems  190 . 
     The microprocessor further controls various systems  192  associated with power generation including control of the louver panels. Control of the louver panels is described with reference to  FIG. 5 . The water current is moving in the direction indicated by the arrow  194 . The speed of the current is sensed by the sensors  182  and a signal is passed to the microprocessor  174 . A signal indicative of the position of the louver panels  140 ,  141 ,  142 ,  143 ,  144 , and  145  is passed to the microprocessor  174  from the sensors  178 . The microprocessor  174  is programmed to compute a projected impact time based upon the received input for each of the louver panels  140 ,  141 ,  142 ,  143 ,  144 , and  145 . 
     In other words, as the louver panels  140 ,  141 ,  142 ,  143 ,  144 , and  145  rotate about the spars  110  and  112  in the direction indicated by arrows  195  and  197 , the microprocessor  174  projects the time at which a line drawn from the respective spar  110  or  112  through the louver panels  140 ,  141 ,  142 ,  143 ,  144 , and  145  is pointed directly toward the direction from which the current is coming (referred to herein as aligned with the current). In  FIG. 5 , the louver panel  140  is nearly aligned with the current. Thus, as the louver panels  140 ,  141 ,  142 ,  143 ,  144 , and  145  continue to rotate past the point at which they are aligned with the current, the microprocessor  174  issues a control signal which causes the louvers  146  on the particular louver panel to move to a closed position, creating a relatively large surface for receiving kinetic energy from the current. 
     The current continues to provide force against the closed louver panels until the louver panel is aligned with the current on the downstream side. In  FIG. 5 , the louver panel  141  is nearly aligned with the current on the downstream side. Beyond this position, any force of the current on the louver panel acts to slow the rotation of the louver panels. Accordingly, the microprocessor  174  issues a control signal causing the louvers  196  (see  FIG. 2 ) on panels that are aligned with the current on the downstream side to open thereby reducing the effective surface area of the louver panel. 
     Those of ordinary skill in the art will further appreciate that the torque on the station  100  from the louver panels  141 ,  143  and  145  are countered by the torque on the station  100  from the louver panels  142 ,  144  and  146 . 
     In one embodiment, the microprocessor  174  is configured to determine predictive “attack angle” and “rate of attack.” This calculation incorporates the rotational speed of the louver panels along with the transition speed of the louvers between the open and closed position to optimize the rotational speed of the louver panels. 
     The microprocessor  174  may further be used to control the louvers  196  to a “full feather” position wherein the controlled louvers  196  move to a full open position to aid in slowing/stopping rotation of the louver panels. Another controlled position is a “full tilt” position where all of the louvers  196  on each of the louver panels are controlled to a fully closed position to provide relatively low vertical resistance when changing the depth of the station  100  such as for semi-surfacing the station  100  for repairs. The louvers  196  may further be controlled to a “selective feather” position where one of the louvers  196  is set to a full open position and locked to allow repair of the motion control system for that louver while the rest of the louvers continue to function as normal in power generation. 
     The microprocessor  174  also provides control functions for the power generation equipment in the power generating nodes  114 ,  116 ,  118  and  120 . Referring to  FIG. 6 , the power generating node  114  includes four levels of modular generators  146 . Each level includes four modular generators  146  arranged about the power axle  138 . The power axle  138  is coupled to four universal gears  198 ,  200 ,  202  and  204 . Each of the generators  146  is coupled to the universal gear  198 ,  200 ,  202  or  204  that is on the same level as the modular generator  146  by a clutch  206 . The microprocessor  174  issues control signals for engaging or disengaging the individual clutches  206 . Accordingly, each of the modular generators  146  may be individually removed from operation to perform maintenance or for replacement without affecting the operation of the remaining thirty-one modular generators  146  in the generating node  114 . 
     Maintenance concerns also factor into the construction of the louvers  196 . By way of example,  FIG. 7  shows a schematic view of a louver  206  and a louver  208 . The position of the louvers  206  and  208  are controlled through crossbars  210  and  212 , The crossbars  210  and  212  are positioned such that the louvers  206  and  208  are somewhat cantilevered toward an open position when current flowing in the direction of the arrow  214  impacts the front surfaces  216  and  218 , respectively. Conversely, when current flowing in the direction of the arrow  220  impacts the back surfaces  222  and  224 , the louvers  206  and  208 , respectively, experience a force moving them toward a closed position. This configuration increases the operational efficiency of the louver panels and reduces the forces on the systems used to control the louvers. The louvers  206  and  208  in this embodiment are also configured to be neutrally buoyant when the station  100  is at the desired depth. Thus, less force is placed upon the various components further reducing maintenance requirements. 
     The auxiliary systems  190  controlled by the microprocessor  174  include an elevator system provided in the spar  108 . As shown in  FIG. 8 , the spar  108  encloses an elevator shaft  220  which extends between the node  122  and the node  124 . The elevator allows for movement of personnel, supplies and equipment between the upper structure  104  and the lower structure  106 . The spars  126 ,  128 ,  130 ,  132 ,  134  and  136  may further be supplied with tracks or guide rails for use in moving equipment or supplies throughout the station. 
     The elevator shaft is located beneath a dry water skirt  222 . The transfer skirt  222  is configured to be used with a vehicle equipped with a high pressure water sweep and a rotary scrub brush. The high pressure water sweep and rotary scrub brush are used to clear biofouling and other debris from the dry transfer skirt  222 . The vehicle then settles onto the dry transfer skirt  222  with the aid of stab pins to provide for proper alignment. A seal on the underside of the vehicle provides a watertight seal between the vehicle and the dry transfer skirt  222 . Once the vehicle is properly positioned, the space within the seal and between the vehicle and the dry transfer skirt  222  is dewatered. The dewatering process lowers the pressure between the vehicle and the dry transfer skirt  222 . Accordingly, a tight seal is maintained by the force of the ambient sea pressure acting upon the vehicle. 
     In accordance with one embodiment, the station  100  is situated at a water depth of 650 to 2,500 feet of seawater (“FSW”). This depth places the station  100  well below the mean water surface in a 100-year storm risk scenario. When incorporating the anchoring and positioning system  150  in 650 FSW, the mud pad  152  is buried at a depth of around 45 feet below the seafloor  154  and the three subsurface buoys  162 ,  164  and  166  that terminate the respective stainless steel tension leg cables  156 ,  158  and  160  are at a minimum of depth of around 165 FSW, still below the mean water surface in a 100-year storm risk scenario. 
     A manned submersible may be used to effect crew changes, delivery of food, hard mail, replacement parts, and to remove sick or injured station workers, and to deliver and replace scientists visiting the scientific observation station. Thusly located well below the “action layer” of the ocean, the station  100  is not significantly impacted by adverse surface/semi-surface conditions such as tsunamis, hurricanes, solar flares, war, etc. The station  100  is thusly also a difficult target for potential terrorism. Further, it should be noted that the louver panels  140 ,  141 ,  142 ,  143 ,  144  and  145  may open, close, and rotate slowly enough to ameliorate adverse impacts on marine life. The station  100  also includes an underwater sound broadcasting system configured to produce sounds at levels and frequencies to induce aversion/diversion maneuvers in most forms of marine life. The impact of invertebrates jellyfish, etc.) on the support columns, and blade surfaces would be comparable to the impact seen on offshore oil production structures or sunken ships. 
     Additionally, in operation the station  100  may provide an auxiliary power dock for submarines to fill their power and fresh water needs during a “submerged power down of their onboard power plants for repair/maintenance, and the station  100  may provide a high voltage power source for long range hydrophonic sub-sea listening/tracking/signal repeating systems. 
     Additionally, as the station  100  is substantially a large metal structure submerged in reasonably cool water (i.e., on the order of 39 degrees F. at a depth of around 650 FSW), the temperature of the ambient water  660  facilitates cooling of the rotating parts with the heat exchangers. 
     While the present invention has been illustrated by the description of exemplary processes and system components, and while the various processes and components have been described in considerable detail, applicant does not intend to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will also readily appear to those ordinarily skilled in the art. The invention in its broadest aspects is therefore not limited to the specific details, implementations, or illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicant&#39;s general inventive concept.