Abstract:
An offshore power generator includes an offshore platform. Current, wind, wave and other renewable energy generators are mounted to the offshore platform. Each current generator has a shroud enclosing a set of blades. A hub member is located within the shroud and extends in an upstream direction from the blades. The flow area between the interior of the shroud and the hub member converges from the shroud inlet to the blades.

Description:
CROSS REFERENCED TO RELATED APPLICATIONS 
   This application is a continuation in part of U.S. application Ser. No. 11/132,489 “Current Power Generator” filed on May 19, 2005 which is incorporated herein in its entirety. This application is also a continuation in part of U.S. application Ser. No. 11/142,145 “Ocean Wave Generator” filed Jun. 1, 2005 which is incorporated herein in its entirety. 

   FIELD OF THE INVENTION 
   The present invention relates to offshore platforms, and in particular to an offshore power generator using a new, existing, abandoned, removed, dumped or relocated fixed or floating offshore platform. 
   BACKGROUND OF THE INVENTION 
   Ordinarily, after an offshore platform has fulfilled its use by extracting all the oil or gas it can from a given location, it is merely discarded. Typically, the platforms are removed to 15 feet below the mudline. Oil companies routinely pay millions of dollars to have the platforms removed and the platforms often become the property of the remover. Many of these platforms are lowered to the seabed in approved dumping sites and are in excellent condition. As a result, the platforms could be re-used for other purposes such as power generation. 
   U.S. Pat. No. 3,946,568 is directed to an offshore oil production platform comprising one section disposed on the sea bed and another section connected to the one section and projecting up above the sea surface. The one section consists of a plurality of prefabricated units comprising at least one tank divided into a plurality of compartments and having a peripheral wall the thickness of which is not adapted to withstand full water pressure with the tank empty in the submerged state, and at least one compartment in the tank has a peripherial wall the thickness of which is adapted to withstand full water pressure when empty in the submerged state. 
   U.S. Pat. No. 5,188,484 is directed to a mobile, self-elevating, offshore production platform, for exploitation of smaller reservoirs, with a liquid tight hull having a deck; a plurality of support legs, each having a gear rack and bottom footpads, which are slidably extendable through the hull; a removable jacking tower for each support leg, and, a locking means for each support leg which is engageable to the leg gear rack at any vertical position of the leg. Mineral processing equipment is pre-installed on the deck at a suitable shoreside facility. Then the platform, with legs elevated, is towed to the offshore location where minerals are to be produced. On location the legs are lowered, grounded, and then pre-loaded to desired criteria by introducing ballast water into the hull. After pre-loading the platform is deballasted and elevated to establish a desired air gap. Upon elevation a locking device is engaged to secure each leg in place and the jacking towers, tower powering equipment, and ballast pumps may then be completely removed for storage, or reuse on other platforms. Installation is completed by connecting the hydrocarbon processing equipment to influent and effluent means provided. Upon depletion of the mineral reservoir, or for other reasons such as the threat of a violent storm, the platform can be removed from one location, and reused at another, by reversing and repeating the above procedure. 
   U.S. Pat. No. 6,139,224 is directed to a semi-submersible platform for offshore oil operation comprising a buoyant sub-structure comprising a base and a plurality of columns upstanding from said base, a buoyant deck-hull mounted on the columns and means for ballasting and deballasting at least the base of said sub-structure. It further comprises means for tangentially guiding said deck-hull on said columns during deployment of the platform into a predetermined configuration by ballasting of the sub-structure while the deck-hull is floating and means for locking said deck-hull to the columns in said predetermined configuration. 
   U.S. Pat. No. 5,573,355 is directed to an offshore oil drilling or producing platform comprising a hull carried by legs provided with feet adapted to rest on the sea bed, characterized in that the walls of each of the legs define a space opening onto the respective foot in which are retracted anchoring piles for the leg carried by the foot, each leg being also provided in its upper part with support means in vertical alignment with the piles within the space defined by the walls of the leg for supporting a device for driving the piles into the sea bed. 
   U.S. Pat. No. 4,025,220 is directed to a fluid-current energy-conversion plant, especially useful for electricity generation, utilizing an axial flow turbine as the energy conversion element, has self-inflated flexible collector elements for capturing a portion of the fluid current, increasing its velocity, guiding at least some of each portion into the turbine&#39;s mouth, then returning the captured flow into the stream. 
   None of the above inventions provide a re-usable offshore oil platform to provide an alternative energy source. It would therefore be beneficial if an alternative energy source utilizing the re-use of decommissioned oil platforms existed to harness energy. 
   SUMMARY OF THE INVENTION 
   It is an aspect of the present invention to provide an offshore power generator utilizing a new, existing, abandoned, removed, dumped, or relocated offshore platforms. 
   It is a further aspect of the present invention to provide an offshore power generator that includes an offshore platform; a support frame mounted to the offshore platform comprising vertical support members and horizontal support members; current generators mounted to the horizontal support members of the support frame; and power cables, in electrical communication with the current generators. 
   It is yet a further aspect of the present invention to provide an offshore power generator that includes an offshore platform; a support frame mounted to the offshore platform comprising vertical support members and horizontal support members; current generators mounted to the horizontal support members of the support frame; cross support beams mounted to the top of the offshore platform; wave generators mounted to the top of the cross support beams; and power cables, in electrical communication with the current generators and the wave generators. 
   In accordance with a first aspect of the present invention, a novel offshore power generator is provided. The novel offshore power generator includes an offshore platform; current generators mounted to the offshore platform; and power cables, in electrical communication with the current generators. 
   In accordance with a further aspect of the present invention, an alternative embodiment of a novel offshore power generator is provided. The novel offshore power generator includes an offshore platform; a support frame mounted to the offshore platform comprising vertical support members and horizontal support members; current generators mounted to the horizontal support members of the support frame; and power cables, in electrical communication with the current generators. 
   In accordance with yet a further aspect of the present invention, a novel offshore power generator is provided including wave generators. The novel offshore power generator includes an offshore platform; a support frame mounted to the offshore platform comprising vertical support members and horizontal support members; current generators mounted to the horizontal support members of the support frame; cross support beams mounted to the top of the offshore platform; wave generators mounted to the top of the cross support beams; and power cables, in electrical communication with the current generators and the wave generators. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing summary, as well as the following detailed description of a preferred embodiment of the present invention will be better understood when read with reference to the appended drawings, wherein: 
       FIG. 1  is a perspective view of an offshore power generator in accordance with the present invention. 
       FIG. 2  is a side elevation view of an offshore power generator in accordance with the present invention including wave generators. 
       FIG. 3  is a schematic view of a plurality of the offshore power generators of  FIG. 1  shown interconnected and to a landside power grid. 
       FIG. 4  is a side elevation view of an alternative embodiment of an offshore power generator having a surface mounted generator. 
       FIG. 5  is a side elevation view of a floating offshore power generator. 
       FIG. 6  is a side elevation view of an alternative embodiment of an offshore power generator. 
       FIG. 7  is a side elevation view of an alternative embodiment of an offshore power generator in accordance with the present invention. 
       FIG. 8  is a side elevation of an alternative embodiment of an offshore power generator having an alternative energy generator on a surface platform and wave generators. 
       FIG. 9  is a perspective view of an alternative embodiment of an offshore power generator having current generators and wave generators in accordance with the present invention. 
       FIG. 10   a  is a side elevation view of an offshore power generator of the present invention having a series of wave generators on the top of the generator. 
       FIG. 10   b  is a perspective view of the offshore power generator of  FIG. 10   a.    
       FIG. 11  is a schematic representation of an ocean generation station. 
       FIG. 12  is a perspective view of an alternative embodiment of a current generator. 
       FIG. 13  is a side elevation view of the current generator of  FIG. 12 . 
       FIG. 14  is a perspective view of an alternative embodiment of a current generator including an alternative embodiment of a wave generator. 
       FIG. 15  is a perspective view of an alternative embodiment of a current generator having a perimeter cone. 
       FIG. 16  is a side elevation view of an alternative embodiment of a current generator having a perimeter cone as depicted in  FIG. 15 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring now to the drawings, wherein like reference numerals refer to the same components across the several views and in particular to  FIGS. 1 ,  2 , and  3 , there is shown an offshore power generator  10 . The offshore power generator  10  includes an offshore platform  20  and current generators  30 . 
   The offshore platform  20  rests on the seabed S and has mounted on it a plurality of generators  30 . Each current generator  30  in this embodiment of the present invention includes a generator  31 , a shaft  33  rotatably mounted within and protruding out of the generator  31 , and a plurality of blades  32  mounted to the shaft  33  to turn the shaft  33  in response to water current flow. Electrically connected to the current generators  30  are power cables  60 . The power cables  60  transmit the energy generated by the current generators  30  for consumption. For example, the power cables  60  may be connected to a power grid G, located onshore. 
   Referring now to  FIG. 2 , the offshore power generator  10  includes an additional wave generator  40  mounted at the top of the offshore platform  20 . The wave generators  40  include a buoy  41 , an anchor leg  42 , and a generator  43  which is operatively connected to the anchor leg  42 . When the buoy  41  rises during a wave crest, the anchor leg  42  turns the generator  43  to generate electricity. 
     FIG. 3  depicts a typical arrangement of a power generation station utilizing a plurality of the offshore power generators  10 . The offshore power generators  10  are connected via underwater power cables  60  to one another and can be connected over underwater power cable bridges to an onshore power grid G. The onshore power grid G can transmit the energy generated by the offshore power generators  10  for a variety of uses. 
   Referring now to  FIG. 4 , an alternative embodiment of an offshore power generator  100  is depicted. The offshore power generator  100  includes current generators  130  under the surface W of the ocean. The current generators  130  are mounted to an offshore platform  120 . Each current generator  130  in this embodiment of the present invention is substantially similar structurally and in operation to the current generators  30 . Each current generator  130  is electrically connected to an external control center  162 , and in turn to power cables  60 . The power cables  60  transmit the energy generated by the current generators  130  and  162  for consumption. For example, the power cables  60  may be connected to the power grid G, located onshore. 
   The offshore power generator  100  in this embodiment also includes an above the water platform  150 . Mounted to the top of the platform  150  is a wind generator  160 . The wind generator  160  includes a shaft  161 , a generator portion  162 , and a windmill  163 . 
   Referring now to  FIG. 5 , an alternative embodiment of an offshore power generator  200  is depicted. The offshore power generator  200  includes a floating platform  210  having a surface portion  211  and a submerged portion  212 . Mounted to the surface portion  211  of the floating platform  210  is the wind generator  160 , which includes a shaft  161 , and a generator portion  163 . In this embodiment, the current generators  130  are mounted to the submerged portion  212  of the offshore power generator  200 . As described in  FIG. 1 , the current generators  130  are substantially similar structurally and in operation to the current generators  30 . Each current generator  130  and wind generator  160  are electrically connected to the electrical control center  162 , and in turn to power cables  60 . The power cables  60  transmit the energy generated by the current generators  130  and  160  for consumption. For example, the power cables  60  may be connected to the power grid G, located onshore. 
   The floating platform  210  is moored to the seabed S by mooring cables  230 . In a preferred embodiment of the present invention, the mooring cables  230  are connected to the submerged portion  212  of the floating platform  210 . However, it is possible that the mooring cables  230  could be connected to the surface portion  211 . 
   Referring now to  FIG. 6 , another embodiment of an offshore power generator  500  is shown. The offshore power generator  500  includes an offshore platform  510 , which has a surface portion  511  and a submerged portion  512 . A current generator frame  520  is mounted to the submerged portion  512  of the offshore power generator  500 . The current generator frame  520  includes vertical support members  513  and horizontal support members  514 . Current generators  530  are mounted to the horizontal support members to generate electricity in response to water current flow. The current generators  530  are substantially similar in structure and operation to the current generators  30  described in  FIG. 1 . Mounted to the surface portion  511  of the offshore platform  510  is a wind generator  560 , which includes a shaft  561 , and a windmill  563 . In a preferred embodiment of the present invention, the windmill  563  turns a generator (not shown) in response to air current. Power cables (not shown) can be electrically connected to any combination of the current generators  530 , or wind generators  560 . The current generators  530  and the wind generator  560  generate power independently of each another and transfer power via the power cables for consumption. The wave generators  40  are substantially similar in structure and operation to the wave generators  40  described in  FIG. 2 . 
   Referring now to  FIG. 7 , another embodiment of an offshore power generator  500  is shown. The offshore power generator  500  includes an offshore platform  510 , and a current generator frame  520  which is mounted to the offshore platform  510 . The current generator frame  520  includes vertical support members  513  and horizontal support members  514 . Current generators  530  are mounted to the horizontal support members to generate electricity in response to water current flow. The current generators  530  are substantially similar in structure and operation to the current generators  30  described in  FIG. 1 . Power cables (not shown) can be electrically connected to the current generators  530  and transfer the power via the power cables for consumption. Since this embodiment has nothing above the water&#39;s surface, it has no visual pollution from shore. All components of this embodiment can also be recessed far enough below the water&#39;s surface to allow boat traffic above. The wave generators  40  are substantially similar in structure and operation to the wave generators  40  described in  FIG. 2 . 
   Referring now to  FIG. 8 , an alternative embodiment of an offshore power generator  600  is depicted. The offshore power generator  600  includes an offshore platform  610 , which has a surface portion  611  and a submerged portion  612 . The offshore platform  610  is mounted to the seabed S. A current generator frame  620  is mounted to the submerged portion  612  of the offshore power generator  600 . The current generator frame  620  includes vertical support members  613  and horizontal support members  612 . Current generators  630  are mounted to the horizontal support members to generate electricity in response to water current flow. The current generators  630  are substantially similar in structure and operation to the current generators  30  described in  FIG. 1 . Mounted to the surface portion  611  of the floating platform  610  is a wind generator  660 , which includes a shaft  661 , and a windmill  663 . In a preferred embodiment of the present invention, the windmill  663  turns a generator (not shown) in response to air current. Wave generators  640  are mounted to the topmost horizontal support member  612  of the support frame  620  to generate electricity from the rising and falling of waves. The wave generators  640  are substantially similar in structure and operation to the wave generators  40  described in  FIG. 2 . Power cables (not shown) can be electrically connected to any combination of the current generators  630 , the wave generators  640 , or the wind generator  660 . For example, the current generators  630 , wave generators  640 , and the wind generator  660  can generate power independently of one another or in any combination with one another to be transferred via the power cables for consumption. 
     FIG. 9  depicts an alternative embodiment of the offshore power generator with only the top of the wave generator above the water&#39;s surface W, minimizing visual pollution. 
     FIGS. 10   a  and  10   b  depict an alternative embodiment of an offshore power generator  700 . The offshore power generator  700  is substantially similar to the submerged portion of the offshore power generator  600  of  FIG. 9 . The offshore power generator  700  includes an offshore oil platform  710  mounted to the seabed S and submerged beneath the surface of the water. A support frame  720  is mounted to the offshore platform  710  and includes vertical support members  713  mounted to the seabed S and horizontal support members  712 . In a preferred embodiment of the present invention, the horizontal support members  712  are mounted generally perpendicularly to the vertical support members  713 , however, the horizontal support members  712  may be attached in any way known to one of ordinary skill in the art. Current generators  720  are mounted to the horizontal support members  712  to generate electricity from water current. The current generators  730  are substantially structurally similar to, and operate substantially similarly to the current generators  30 . Mounted to the top of the topmost portion of the offshore platform are horizontal support members  732  with a series of cross support beams  735  upon which wave generators  740  are mounted. The wave generators  740  are substantially structurally similar to, and operate substantially similarly to the wave generators  40 . Power cables (not shown) can be electrically connected to the current generators  730 , and to the wave generators  740  to transfer the electrical energy from the current generators  730  and the wave generators  740  for consumption, for example, via a power grid (not shown). In a preferred embodiment of the present invention, the wave generators  740  generate electricity independent of the current generators  730 . 
     FIG. 11  represents a typical arrangement of offshore power generators such as  10 ,  100 , and  500  all interconnected to the power cables  60  and to the power grid G onshore. In addition to the offshore power generators, alternative energy generators  1600  may be added to the arrangement to provide additional energy production along side the offshore power generators. In a preferred embodiment of the present invention, the alternative energy generators  1600  are wind power generators, however, any alternative energy generators known to one of ordinary skill in the art may be used. Furthermore, although only offshore power generator embodiments  10 ,  100 , and  500  are depicted in  FIG. 11 , any combination of any of the embodiments of the offshore power generators may be used. 
     FIGS. 12 and 13  depict an alternative embodiment of a current generator  2000 . The current generator  2000  includes blades  2021  mounted to a shaft  2027 . The current generator, in a preferred embodiment, is mounted to a horizontal support frame  2012 . 
   When the blades  2021  are rotated by the current flow F, the blades  2021  turn the shaft  2027  which generates power. An extension shaft  2026  is mounted to the generator  2000  and proceeds generally perpendicularly outward therethrough. The extension shaft  2026  is attached to the horizontal support frame  2012 . Disposed on the extension shaft  2026  proximate the horizontal support frame  2012  are electrical contactors  2025 . The electrical contactors  2025  are electrically connected to power cables  60  to transfer the electricity generated by the generators  2000  to a power grid (not shown). The generator  2000  is pivotally mounted to the extension shaft  2026  so as to allow the generator  2000  to pivot about its axis in the direction of the arc A, or in the opposite direction to arc A. 
   A cone  2023  is disposed around the shaft  2027  of the generator  2000  to direct current flow F onto the blades  2021 . The cone  2023  includes a nose section  2024  to direct current flow F outward toward the blades  2021 . In a preferred embodiment of the present invention, the cone  2023  responds to current flow F in order to align with the current flow F, similar to a weathervane. As the cone  2023  weathervanes to align with the current flow F, the shaft  2026  causes the generator  2000  to pivot about its axis. Furthermore, the current flow F causes the plurality of blades  2021  to rotate the shaft  2027 , which in turn operates the generator  2000  to generate electricity. 
     FIG. 14  depicts an alternative arrangement of the current generator  2000  that includes the addition of a wave generator  4000 . The current generator  2000  and the wave generator are mounted to a frame  2050 , which includes vertical support members  2013  and the horizontal support members  2012  disposed substantially perpendicularly to the vertical support members  2013 . 
   The wave generator  4000  includes a buoy  4010 , a pair of anchor cables  4020 , a generator  4030 , and a pair of pulleys  4015  disposed at either end of the buoy  4010 . 
   The buoy  4010  floats on the surface of the ocean and rises and falls as the waves rise and fall. The anchor cables  4020  are connected to the pulley  4015  at one end and to the uppermost horizontal support member  2012  of the support frame  2050 . The generator  4030  is operatively attached to the pulleys  4015  and turns when the pulleys  4015  turn to generate electricity. 
     FIGS. 15 and 16  depict an alternative embodiment of a current generator  3000 . The current generator  3000  includes blades  3021  mounted to a shaft  3027 . The current generator  3000 , in a preferred embodiment, is mounted to a horizontal support frame  3012 . 
   When the blades  3021  are rotated by the current flow F, the blades  3021  turn the shaft  3027  which generates power. An extension shaft  2026  is mounted to the generator  3000  and proceeds generally perpendicularly outward therethrough. The extension shaft  3026  is attached to the horizontal support frame  3012 . Disposed on the extension shaft  3026  proximate the horizontal support frame  3012  are electrical contactors  3025 . The electrical contactors  3025  are electrically connected to power cables to transfer the electricity generated by the generators  3000  to a power grid (not shown). The generator  3000  is pivotally mounted to the extension shaft  3026  so as to allow the generator  3000  to pivot about its axis in the direction of the arc A, or in the opposite direction to arc A. 
   A cone  3023  is disposed around the shaft  3027  of the generator  3000  to direct current flow F onto the blades  3021 . Cone  3023  comprises a hub with a downstream end at blades  3021 . The cone  3023  includes an upstream nose section  3024  to direct current flow F outward toward the blades  3021 . In a preferred embodiment of the present invention, the cone  3023  responds to current flow F in order to align with the current flow F, similar to a weathervane. As the cone  3023  weathervanes to align with the current flow F, the shaft  3026  causes the generator  3000  to pivot about its axis. Furthermore, the current flow F causes the plurality of blades  3021  to rotate the shaft  3027 , which in turn operates the generator  3000  to generate electricity. 
   A shroud  3011  is disposed upon the extension shaft  3026  and proceeds substantially circumferentially around the blades  3021 . The shroud  3011  diverts current flow F on the outer edges of the blades  3021  toward the blades  3021 . A plurality of wave generators  4000  may be mounted to the uppermost horizontal support member  3012 . 
   In a preferred embodiment of the present invention, the wave generators and their components described herein are substantially similar to the wave generators described in U.S. patent application “Ocean Wave Generator” having a Ser. No. 11/142,145 filed Jun. 1, 2005 by Donald H. Gehring, which is incorporated herein in its entirety. Similarly, the current generators, and their components described herein are substantially similar to the current generators described in U.S. patent application “Current Power Generator” having a Ser. No. 11/132,489 filed on May 19, 2005 by Donald H. Gehring and incorporated herein in its entirety. 
   In view of the foregoing disclosure, some advantages of the present invention can be seen. For example, a novel offshore power generator is provided. The novel offshore power generator utilizes new, existing, abandoned, removed, dumped or relocated fixed or floating offshore platforms as energy generators. 
   While the preferred embodiment of the present invention has been described and illustrated, modifications may be made by one of ordinary skill in the art without departing from the scope and spirit of the invention as defined in the appended claims.