Abstract:
A carpet of wave energy conversion (CWEC) device mechanically couples an absorber carpet to one or more energy converters, thereby allowing for wave energy extraction from passing waves. The absorber carpet may be flexible material of a composite material that has a low elastic modulus in a longitudinal direction (to allow for stretching), and a relatively higher elastic modulus in a transverse direction (to better couple energy from wave to converters). Such designs have minimal wave reflections and high efficiencies within a relatively short extent of deployment. The resultant converted useful energy is available as either: 1) mechanical power including direct desalinization or electrical production; or 2) hydraulic power for a number of applications (including hydraulically powered motors supplying power to powered devices including generators), or pumping of the wave medium under pressure to an alternate location for irrigation or energy storage.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a 35 U.S.C. §111(a) continuation of PCT international application number PCT/US2014/035056 filed on Apr. 22, 2014, incorporated herein by reference in its entirety, which claims priority to, and the benefit of, U.S. provisional patent application Ser. No. 61/814,379 filed on Apr. 22, 2013, and which claims priority to, and the benefit of, U.S. provisional patent application Ser. No. 61/974,432 filed on Apr. 2, 2014. Priority is claimed to each of the foregoing applications. 
         [0002]    The above-referenced PCT international application was published as PCT International Publication No. WO 2014/176293 on Oct. 30, 2014, which publication is incorporated herein by reference in its entirety. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0003]    Not Applicable 
       INCORPORATION-BY-REFERENCE OF COMPUTER PROGRAM APPENDIX 
       [0004]    Not Applicable 
       NOTICE OF MATERIAL SUBJECT TO COPYRIGHT PROTECTION 
       [0005]    A portion of the material in this patent document is subject to copyright protection under the copyright laws of the United States and of other countries. The owner of the copyright rights has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the United States Patent and Trademark Office publicly available file or records, but otherwise reserves all copyright rights whatsoever. The copyright owner does not hereby waive any of its rights to have this patent document maintained in secrecy, including without limitation its rights pursuant to 37 C.F.R. §1.14. 
       BACKGROUND OF THE INVENTION 
       [0006]    1. Field of the Invention 
         [0007]    This invention pertains generally to wave energy extraction, and more particularly to wave energy extraction using an absorber carpet actuating one or more energy converters. 
         [0008]    2. Description of Related Art 
         [0009]    Some traditional wave energy extraction systems use windmill-styled blades that are injurious to marine life, and pose significant hazards to shipping. Photovoltaic systems only work when the sun is shining. 
       BRIEF SUMMARY OF THE INVENTION 
       [0010]    A Carpet of Wave Energy Conversion (CWEC) apparatus harvests ocean wave energy and converts it into usable power. This design can be classified as a combination of power conversion technologies using the differential pressure and the relative motion between an incoming wave and absorber carpet, and may be designed for near shore, shallow water, and bottom standing locations either directly on the bottom or suspended over the bottom by pillars. Alternatively, the design may be designed for open water extraction by floating slightly submerged by using gravity mooring. The device may be operated in heave or pitch motion, where the converter&#39;s orientation is a combination of attenuator and terminator. 
         [0011]    The CWEC comprises a synthetic seabed carpet, a power take off (PTO) system, and a mooring system when placed in non-open-water locations. The energy stored in overtopping waves is damped out by an artificial seabed absorber carpet and converted into working energy using energy converters of various kinds that are mechanically connected to the carpet and a frame. In the case of a hydraulic PTO, the generated hydraulic energy can be used to run a hydro turbine (typically a Francis turbine), supply a reverse osmosis chamber with high pressure, or can be efficiently stored as hydraulic head prior to subsequently being converted into electricity. 
         [0012]    Near shore, the CWEC operates completely submerged, and hence imposes minimal danger to vessels and to the sea life (i.e. no mammal entanglement) compared to existing wave energy converters. The absorber carpet is capable of surviving high momentum storm surges and in fact performs even better under very energetic (e.g. stormy) sea conditions. Most existing wave energy converters require shutdown in such storm conditions by going into an idle or other (typically inactive) protective mode. 
         [0013]    The CWEC and its variations may also be used to create localized safe havens for fishermen in open seas by floating the entire device, or if implemented on a relatively large scale, to protect shores and harbors against strong storm waves. 
         [0014]    The CWEC generates hydraulic power by absorbing and converting wave energy. The extracted hydraulic energy can be used for several applications. The transmitted hydraulic power may be used to run a Francis reaction turbine. The torque generated in this turbine may be used to generate electricity via three-phase alternating circuit synchronous motors or other generators. 
         [0015]    The high-pressure seawater may additionally be used to supply a reverse osmosis desalination plant through direct pressurization of sea water, or indirectly through electrical generation and subsequent desalination use. Direct mechanical power may also be used in an energy converter to directly convert the incoming mechanical power to electrical power. Additionally, the harvested energy can be stored without significant losses over time, and later converted to electricity at times with higher electrical power demand and thus higher utility prices. This may be a major advantage over electrical power take off systems of wave energy conversion, photovoltaic, and wind energy. 
         [0016]    The CWEC device mechanically may also couple an absorber carpet to one or more energy converters, thereby allowing for energy extraction from waves passing over. The absorber carpet is a water impermeable flexible material, that constructive implementation can comprise a composite material. The designs presented here yield minimal wave reflections and have theoretical efficiencies asymptotically approaching unity within a finite and (relatively) short extent of deployment. Wave energy may be extracted hydraulically or mechanically. 
         [0017]    Direct energy extraction may be used to power linear generators, or rotary generators or alternators through use of rack and pinion gearing. Direct energy extraction may be used to mechanically pressurize sea water to the ≧5.5 MPa typically required for most reverse osmosis membranes to function in desalinization plants. 
         [0018]    The useful energy output from the energy convert is available as hydraulic power for a number of applications, including direct desalinization, hydraulically powered motors supplying power to powered devices including generators, direct pumping of the wave medium to an alternate location for irrigation or energy storage. 
         [0019]    Further aspects of the invention will be brought out in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing preferred embodiments of the invention without placing limitations thereon. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         [0020]    The invention will be more fully understood by reference to the following drawings which are for illustrative purposes only: 
           [0021]      FIG. 1A  is a simplified side view embodiment of a 1-D absorber carpet with PTO units in the center of a Carpet of Wave Energy Conversion (CWEC) system. 
           [0022]      FIG. 1B  is a detailed side view of the construction of the 1-D absorber carpet. 
           [0023]      FIG. 2A  is a top view of an alternative embodiment of a Carpet of Wave Energy Conversion (CWEC) system. 
           [0024]      FIG. 2B  is a bottom view of the alternative embodiment of the absorber carpet of  FIG. 2A . 
           [0025]      FIG. 2C  is a side view of the alternative embodiment of the absorber carpet of  FIG. 2A . 
           [0026]      FIG. 2D  is an end view of the alternative embodiment of the absorber carpet of  FIG. 2A . 
           [0027]      FIG. 3  is a system schematic for the Carpet of Wave Energy Conversion previously described in  FIG. 1A  through  FIG. 1B . 
           [0028]      FIG. 4  is a side view of a mechanical model of the composite absorber carpet. 
           [0029]      FIG. 5  is an assembly drawing of how the CWEC of  FIG. 2A  through  FIG. 2D  is built. 
           [0030]      FIG. 6A  is a perspective view of an experimental CWEC setup. 
           [0031]      FIG. 6B  is a perspective view of the experimental CWEC setup of  FIG. 6A  with outlets attached. 
           [0032]      FIG. 7  is a perspective view of a two dimensional CWEC. 
           [0033]      FIG. 8A  is a side view of an elevated CWEC moored by mooring lines to footings disposed in the floor of the body of water. 
           [0034]      FIG. 8B  is a top view of the CWEC of  FIG. 8A . 
           [0035]      FIG. 8C  is a variation on the design of  FIG. 8A  and  FIG. 8B , with footings directly connecting to the frame. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0036]    Refer now to  FIG. 1A , which is a simplified side view  100  embodiment of a Carpet of Wave Energy Conversion (CWEC)  102 . The CWEC  102  begins with an absorber carpet  104  that interacts with an incoming wave  106  to extract energy from the wave  106 . The result is an incoming wave  106  of amplitude A in    108  exiting the CWEC  102  with a diminished output amplitude of A out    110 . The difference between the A in    108  and A out    110  relates to the energy extracted from the wave  106  by the CWEC  102 . 
         [0037]    A wave absorption efficiency may be defined as a ratio 
         [0000]    
       
         
           
             
               
                 E 
                 in 
               
               - 
               
                 E 
                 out 
               
             
             
               E 
               in 
             
           
         
       
     
         [0000]    where the outgoing energy E out  of the wave  106  is related to A out    110 , and the incoming energy E in  of the wave is related to A in    108 . The CWEC  102  may have very high wave absorption efficiencies, approaching unity. 
         [0038]    For the CWEC  102  to generate power, the absorber carpet  104  couples incoming wave  106  energy to one or more (preferably double action) pumps  112  spaced apart by D pump    114 . Each pump  112  has one or more check valves  116  used for operation. In the case of a double action pump  112 , there would be four check valves  116 . 
         [0039]    The CWEC  102  may be mounted to ground  118 , which in many cases would be a sea floor near a beach. 
         [0040]    To actuate the pump  112 , a connection  120  is mechanically linked between the absorber carpet  104  and the double action pump  112 . 
         [0041]    Refer now to  FIG. 1B , which is a detailed side view of the construction of the absorber carpet  104 . Transverse stiffeners  122  act as battens to contain an elastic sheet  124 . Such transverse stiffeners  122  are generally fastened through the elastic sheet  124  with one or more fasteners  126 . 
         [0042]    One or more of the transverse stiffeners  122  are slidably connected (not shown here) to one or more longitudinal members  128 . The longitudinal members  128  may be connected with strapping (described below) that uses the same fasteners  126 , and may use washers  130 . 
         [0043]    The longitudinal members  128  are generally flexible, transmitting a stress from one transverse stiffener  122  to the next, but transmitting little in the way of moment. In alternate embodiments, the longitudinal members  128  may consist of a flexible member, a fiberglass bar, and a combination of the foregoing, etc. The longitudinal members  128  are generally resistant to corrosion, rot, or other degradation due to sustained immersion in the medium of the incoming wave  106  (of  FIG. 1A ). Due to their interactions with the incoming wave  106 , the longitudinal members  128  are subject to continuous long term flexure, and are designed for such repetitive stress loadings to last for many years of operation. 
         [0044]    The connection  120  between the pump  112  and the absorber carpet  104  may take place at the longitudinal members  128 , the transverse stiffeners  122 , directly on the elastic sheet  124 , or one or more of the foregoing. In one embodiment, the connection  120  takes place proximal to where the longitudinal member  128  crosses the transverse stiffener  122  via a connector  132 . 
         [0045]    Refer now to both  FIG. 1A  and  FIG. 1B . Since the absorber carpet  104  tends to move back and forth horizontally  134 , as well as up and down vertically  136 , the connection  120  and the pump  112  allow for such motions. The low pressure inlet line  138  and the high pressure outlet line  140  attaching to the pump  112  may be mounted so as to pivot along the same axis of rotation as a pivoting mount  142 . Alternatively, the inlet line  138  and the outlet line  140  may simply flex with the rotational movement of the pump  112 . 
         [0046]    The pivoting mount  142  is generally attached to a frame  144 , which mounts most of the components of the CWEC  102 . The frame  144  has pivoting carpet end mounts  146  for connecting the absorber carpet  104  to the frame  144 . 
         [0047]    In still another embodiment, the connection  120  may be sufficiently flexible so as to accommodate the horizontal  134  movement of the absorber carpet  104 , yet not buckling with axial loads operating the pump  112 . 
         [0048]    A power take off system (PTO)  148  may be interconnected with the inlet line  138  and outlet line  140 , allowing for the use of power external to the CWEC  102 . In this sense, the PTO  148  may be any hydraulically actuated device  150 , or may be a hydraulically actuated rotating device, such as a motor (not shown here). Such a motor may also drive electric power generating equipment (also not shown here). 
         [0049]    In still another embodiment, the hydraulically actuated device  150  may be a pressurized or non-pressurized storage container (for instance, reservoir  156 ) capable of storing hydraulic head for future use through a hydraulic motor (not shown). 
         [0050]    The absorber carpet  104  may comprise a composite material that consists partly of the elastic sheet  124  with a low modulus of elasticity and partly of longitudinal members  128  that have a high shear modulus. Both components are connected via a sliding bearing (described later for clarity). The width of the elastic sheet  124  is stiffened by transverse stiffeners  122  located at the top and underneath the elastic sheet  124 . 
         [0051]    The transverse stiffeners  122  clamp the elastic sheet  124  via fasteners  126 , or different fasteners  130 , and provide for a mechanical power transfer connection  120  to the pump  112 . 
         [0052]    The connection  120  directly connects the top of the pump  112  with a longitudinal member  128  at one or more bearing positions of the CWEC  102  along the absorber carpet  104 . Ideally, such bearing and pump  112  positions relate to typical incoming wave  106  lengths enjoyed at a particular mounting position of the CWEC  102 . 
         [0053]    The pump  112  comprises a double acting reciprocating positive displacement pump, otherwise referred to as a double acting pump  112 . The connection  120  connects to the pump  112  to the absorber carpet  104 . The pivoting mount  142  generally attaches the frame  144  to the bottom of the pump  112  at the CWEC  102 . 
         [0054]    The CWEC  102  is generally located submerged on the bottom of the ocean or a wave tank. Waves passing over the device generate a pressure field and thus a sinusoidal upwards and downwards oriented load on the absorber carpet  104 . The forces are calculated over the pressure on a specific area. The absorber carpet  104  is accelerated and displaced vertically in an oscillating motion. The forces created by the waves on the absorber carpet  104  top surface are transmitted via the transverse stiffeners  122  and the longitudinal members  128  to the pumps  112 . 
         [0055]    The elastic sheet  124  is clamped at specific sections by transverse stiffeners  122 . These transverse stiffeners  122  provide a sliding bearing connection between the elastic sheet  124  and the longitudinal members  128 . At the power take off point, the bars creating the connection are connected with a double reacting reciprocating positive displacement pump  112  located underneath the absorber carpet  104 . 
         [0056]    Along the CWEC  102  wave  106  propagation direction, several pumps  112  are located. The bundled forces of the wave  106  are transmitted to the connection  120  of the pump  112 . The pump  112  may generally be a positive displacement pump that comprises a cylindrical piston, a cup seal, a connection  120  (also known as a piston shaft) and four check vales  116 . 
         [0057]    The lower end of the pump shaft is connected to a cup seal which divides the cylindrical piston of the pump into an upper and lower section. Every section has one inlet and one outlet check valve  116 . If the connection  120  pump shaft moves vertically upwards, the lower section of the pump  112  is filled with low pressure water from the supply to inlet line  138 . The water filled pump  112  upper section is compressed by the cup seal, thereby pressurizing the water in outlet line  140  and flowing the contents of the upper section into the outlet line  140 , thereby performing mechanical work (a force multiplied by a distance). In this manner, wave  106  energy is extracted. 
         [0058]    If the pressure in outlet line  140  exceeds a pressure relief valve  152  actuation pressure, then fluid in the high pressure outlet line  140  is released. Such fluid release may be piped to external head storage (for instance reservoir  156 ) for additional over all CWEC  102  system efficiency. 
         [0059]    If the connection  120  shaft of the pump  112  moves vertically downwards, the process described above is performed with the lower and upper section of the pump  112  operationally reversed. 
         [0060]    It should be noted that the high pressure outlet line  140  can be arranged as a series of power sources by providing a previous CWEC (not shown here) that routes its pressurized output to a high pressure inlet  154 , thereby providing additional flow to the high pressure outlet  140  line. 
         [0061]    Furthermore, the high pressure outlet line  140  can be routed externally from the CWEC  102 , and simply used to fill a higher elevation (above the wave  106  level) reservoir  156  through discharge  158  of the high pressure outlet line  140 . In this manner the hydraulic head of the high pressure outlet line  140  may be stored for peak power demand times or times when wave  106  power input is lower than the required CWEC  102  produced power output. 
         [0062]    Finally, it should be noted that  FIG. 1A  and  FIG. 1B  both show a low pressure inlet line  138 . However, the pump  112  may be alternatively supplied by the ambient medium of the wave  106 , e.g. typically fresh or sea water. 
         [0063]    Refer now to  FIG. 2A , which is a top view  200  of an alternate embodiment of an absorber carpet  202 . Here, transverse stiffeners  204  are distributed along the longitudinal direction of the absorber carpet  202  along the top side  206  of the absorber carpet  202 . 
         [0064]    Refer now to  FIG. 2B , which is a bottom view  208  of the alternative embodiment of the absorber carpet  202  of  FIG. 2A . Here, one sees still more transverse stiffeners  204  distributed along the longitudinal direction of the absorber carpet  202  along the bottom side  210  of the absorber carpet  202 . 
         [0065]    On the bottom side  210 , there are two longitudinal members  212 , which are slidably connected to the bottom  210  transverse stiffeners  204  by sheet metal sleeves  214 . Longer sheet metal sleeves  216  provide mounting locations  218  for pump (not shown here) connections. 
         [0066]    Refer now to  FIG. 2C , which is a side view  220  of the alternative embodiment of the absorber carpet  202  of  FIG. 2A . Here, it is apparent that the transverse stiffeners  204  are connected to the absorber carpet  202  via through fasteners  222 , constraining an elastic sheet  224  between each set of transverse stiffeners  204 . 
         [0067]    Refer now to  FIG. 2D , which is an end view  226  of the alternative embodiment of the absorber carpet  202  of  FIG. 2A . Nearly all items have been previously described above in  FIG. 2A  through  FIG. 2C , however, this view better shows washers  228  spaced between the transverse stiffeners  204  and sheet metal sleeves  214  that allow for sliding movement of the longitudinal members  212 . 
         [0068]    Refer now to  FIG. 3 , which is a system schematic  300  for the Carpet of Wave Energy Conversion (CWEC) previously described in  FIG. 1A  through  FIG. 1D . From an energy flow standpoint, an impinging wave  302  brings energy into the CWEC system boundary  304 . From the impinging wave  302 , energy is extracted  306 , resulting in a lower energy transmitted wave  308 . 
         [0069]    Now refer to  FIG. 3 , as well as previously described  FIG. 1A  through  FIG. 1B . The CWEC  102  system operates using the low pressure inlet line  138  and high pressure outlet line  140  attaching to the pump  112 . The inlet line  138  contains low pressure fluid  310  of the ambient medium, typically salt water, although fresh water or other liquids would tend to work equally well. The low pressure fluid  310  is used to fill the pump(s)  312  ( 112  of  FIG. 1A ) through the action of the incoming wave  302 , resulting in a pump full of low pressure fluid  314 . At  316 , another incoming wave  302  is converted to wave energy  306  that pressurizes the fluid, thereby creating a relatively higher pressure fluid  318  in the pump, which is output to the high pressure outlet line  140  shown in  FIG. 1B . This high pressure fluid  320  is maintained at a pressure below that of a pressure relief valve  322 , thereby protecting the apparatus from overpressure situations. The high pressure fluid  320  may be used for power take off purposes as needed external to the system boundary  304  for use as a power source  324 . 
         [0070]    A check valve (not shown here) may be used to ensure one way flow of the high pressure fluid  320  out of the system boundary  304  for use as a power source  324 . 
         [0071]    Refer now to  FIG. 4 , which is a side view  400  of a mechanical model of an anisotropic composite absorber carpet  402 . Along an x-axis  404 , the absorber carpet  402  is characterized by a low elastic modulus for easy flexure. Along the y-axis  406 , a higher shear modulus is desired to avoid nodal building. As these material properties are not fulfilled by a single material, a functional separation of the composite absorber carpet  402  is achieved by creating a composite material. 
         [0072]    The two conflicting anisotropic material requirements are met separately by individual materials connected with each other, thereby creating the composite absorber carpet  402 . The low elastic modulus requirement is provided by a continuous material  408  with the desired properties with a length of L c . 
         [0073]    A different second material  410  that has a high shear modulus is connected via floating bearings  412  with the continuous material  408 , located with the distance d bar    414  to each other. Shear forces on the composite absorber carpet  402  bend the second material  410  such that the operational forces will be distributed  416 . 
         [0074]    Along the x-axis  404  an elastic material behavior, thus a low Young&#39;s modulus is desired to allow the continuous material  408  to change its initial length. As a pump connection would exert a y-axis  406  force on the carpet, a sole elastic material would lead to a formation of nodes of the carpet with nodal points at the pump units  418 . As the converted energy is directly related to the displacement of the carpet at the position of the pump units  418 , no energy would be converted in this case. Therefore, along the y-axis  406  a high bending stiffness in the second material  410  is desired to avoid such nodal building. 
         [0075]    Refer now to  FIG. 5 , which is an assembly drawing  500  of how the CWEC  102  of  FIG. 2A  through  FIG. 2D  is built. Here, a transverse stiffener  204  first attaches to one side of the elastic sheet  224 , and then another transverse stiffener  204  attaches to the other side of the elastic sheet  224 . One mounting location  218  is spaced above the  204  via spacers  502  to permit longitudinal sliding of  212 . The mounting locations  218  also permit attachment of the connector  132  as well as the connection  120  of  FIG. 1A  through  FIG. 1B . The connector  132  is restrained by a mounting plate  504 . 
         [0076]    In one embodiment, an end of the elastic sheet  224  wraps around a frame  506  portion, and is restrained by another transverse stiffener  204  that is attached via through fasteners  222 . 
         [0077]    Refer now to  FIG. 6A , which is a perspective view  600  of an experimental CWEC setup. The absorber carpet  602  is hooked into the frame  604  on both ends with some pretension added through turnbuckles  606 . The five double action pumps  608  are positioned at equal distances in the symmetrical center of the absorber carpet  602  and connected to the carpet as previously shown in  FIG. 5 . The double action pumps  608  are not connected yet to the consumer pipe at this stage of assembly. In actuality, the double action pumps  608  are formed by a combination of two single action pumps  610  arranged in alternating pump actuation directions. 
         [0078]    Refer now to  FIG. 6B , which is a perspective view  612  of the experimental CWEC setup of  FIG. 6A  with outlets attached. Here, the outlet  614  piping has been attached to the various double action pumps  608 . Note here that the inlet  616  is open to the ambient medium, significantly simplifying construction. 
         [0079]    Refer now to  FIG. 7 , which is a perspective view of a two dimensional CWEC  700 . Here, a larger absorber carpet  702  (transparent here for clarity) is disposed above a mesh of stiffeners  704  that are coupled to double action pumps  706  that are modeled here as typical mechanical engineering spring/dashpot systems. The artificial seabed carpet or absorber carpet  702  is indicated through lines connecting the double action pumps  706 , spanning the impermeable absorber carpet  702  above the double action pumps  706 . 
         [0080]    These double action pumps  706  symbols represent any mechanical system capable of extracting wave energy through the deflection of the absorber carpet  702 . One non-limiting example of such a mechanical system is a double action pump. 
         [0081]    The CWEC  102  previously described in  FIG. 1A  and  FIG. 1B  was specifically developed for a wave tank with the width of 0.45 m of wave crest perpendicular to propagation direction. However, the two dimensional CWEC  700  may be designed to be modular in length as well as in width. This means that the current ratio of double action pump  706  units per absorber carpet  702  length can be arbitrarily changed according to the desired boundary conditions of the environment for which the device is designed for. 
         [0082]    For example in an application in the ocean, where wave lengths in the order of 100 m may occur, the length of the absorber carpet  702  can be adjusted to a full, half, or quarter wave length. For such an absorber carpet  702  length, the number of PTO units will significantly increase, as shown here with 9 double action pumps  706  in a longitudinal direction, and 5 double action pumps  706  in a transverse direction, yielding a total of 45 double action pumps  706 . 
         [0083]    As the energy transmitted in ocean waves is quantified in kW per meter wave crest, the area of the two dimensional CWEC  700  device defines the amount of energy to which it is exposed. Therefore the spatial disposition of double action pumps  706  units/m 2  wave crest perpendicular to the wave propagation direction can be arbitrarily adjusted as desired. 
         [0084]    The CWEC  700  of  FIG. 7  shows a version of the CWEC  700  located at the ocean floor  708  with multiple double action pump  706  units perpendicular to the wave propagation direction, along one ocean wave crest. 
         [0085]    The CWEC  700  combines the advantages of a point absorber, an attenuator, and a terminator: It is wave direction independent, has a high absorption efficiency, and can be exposed to high wave energy flux with its flexible absorber carpet spread perpendicular to the wave-propagation direction. The ability to cancel waves can be used to create safe zones in the ocean, prevent erosion and protect harbors. Secondly, the CWEC  700  functions primarily as an energy conversion device that creates seawater at high pressure. 
         [0086]    The high pressure water can be used to generate electricity, directly used for desalination, and used for the distribution of fresh water through direct pumping of the double action pumps  706 . High pressure water can additionally supply pumped-storage hydroelectric power plants, which are a very efficient way to balance the electrical grid. 
         [0087]    Refer now to  FIG. 8A , which is a side view  800  of an elevated CWEC  802  moored by mooring lines  804  to footings  806  disposed in the floor  808  of the body of water. Here, a frame  810  connects to the mooring lines  804  retaining the CWEC  802 . An absorber carpet  812  has energy extracted through one or more pumps  814  attached on one end to the absorber carpet  812  and on the other end to the frame  810 . In this manner, energy from the incoming wave  816  may be extracted by the CWEC  802 . 
         [0088]    Refer now to  FIG. 8B , which is a top view  818  of the CWEC  802  of  FIG. 8A . Here, it is easier to observe that mooring lines  804  attach from the footings  806 . Also, observe that the inlet lines  820  and outlet lines  822  provide incoming and outgoing flux from the pumps  814  of  FIG. 8A . 
         [0089]    Refer now to  FIG. 8C , which is a variation  824  on the design of  FIG. 8A  and  FIG. 8B , here with footings  826  directly connecting to the frame  810 . 
         [0090]    Referring back to  FIG. 8A , it is seen that floats  828  may be attached to the frame  810  to provide flotation to the CWEC  802 , and that by lengthening the mooring lines  804 , the CWEC  802  may be floated to the surface, allowing for initial installation, as well as subsequent repair of the CWEC  802 . 
         [0091]    In the preceding  FIG. 1A  through  FIG. 8C , it is seen that there are many examples of means for extracting energy from waves. These may be 1-D systems, as shown in  FIG. 1A through 2D , or 2-D systems, as shown in  FIG. 7  through  FIG. 8C , without limitation. In all cases, an absorber carpet operates to interact with incoming waves to extract mechanical energy from the wave through the operation of energy converters. Typically, such energy converters are pumps, but they may also be directly driven hydraulic actuators, desalinization components, reverse osmosis (and typically higher pressure) pumps, direct drive generators or alternators, and the like. Herein, a pump acts as an energy converter. 
         [0092]    Without limitation, any method by which mechanically input energy through the work done on a connector ( 120  of  FIG. 1A ) serves as a means for extracting of the wave energy. 
         [0093]    From the discussion above it will be appreciated that the invention can be embodied in various ways, including the following: 
         [0094]    1. A wave energy conversion apparatus, comprising: (a) an absorber carpet comprising a first end and a second end; and (b) a plurality of energy converters, each energy converter coupled to the absorber carpet; (c) wherein an incoming wave that interacts with the absorber carpet causes a movement of the absorber carpet, thereby operating one or more of the plurality of energy converters. 
         [0095]    2. The apparatus of any preceding embodiment, wherein at least one of the ends of the absorber carpet comprises: (a) one or more transverse stiffeners attached to an elastic sheet along a transverse extent; (b) one or more fasteners that fastens the elastic sheet to the one or more transverse stiffeners; (c) one or more through holes that pass through the one or more transverse stiffeners, as well as through the elastic sheet; and (d) one or more turnbuckles attached to the through hole at one end, and substantially fixed to a frame at another end; (e) where the turnbuckles tension the elastic sheet. 
         [0096]    3. The apparatus of any preceding embodiment, wherein the absorber carpet comprises: (a) one or more transverse stiffeners attached to an elastic sheet along a transverse extent; (b) wherein the attachment between the transverse stiffeners and the elastic sheet is selected from one or more of a group of attachments consisting of: a mechanical attachment, a threaded attachment, a glued attachment, a cross linked attachment of the elastic sheet, a woven attachment, and an integral attachment of the transverse stiffener in the elastic sheet. 
         [0097]    4. The apparatus of any preceding embodiment, wherein at least one of the ends of the absorber carpet comprises: (a) an elastic sheet mounted to a frame; (b) wherein the elastic sheet is tensioned by a preloaded stretch of the elastic sheet as it is attached to the frame. 
         [0098]    5. The apparatus of any preceding embodiment, wherein the absorber carpet comprises a material selected from a group of materials consisting of: a flexible material; a water impermeable flexible material; a rubber; a urethane; a polyvinyl chloride; an acrylonitrile butadiene styrene (ABS); a nylon; and a polyoxymethylene. 
         [0099]    6. The apparatus of any preceding embodiment, wherein one or more of the energy converters are selected from a group of energy converters consisting of: a single action hydraulic pump; a double action hydraulic pump; a linear electrical generator; a rack and pinion that drives a generator; and a rack and pinion that drives an alternator. 
         [0100]    7. The apparatus of any preceding embodiment, wherein one or more of the energy converters directly pressurize a source water for reverse osmosis purification of the source water into a purified water output. 
         [0101]    8. The apparatus of any preceding embodiment, wherein the absorber carpet comprises: (a) an elastic sheet comprising a longitudinal and a transverse extent; (b) one or more transverse stiffeners connected to the elastic sheet along the transverse extent; (c) one or more longitudinal members attached to at least two of the transverse stiffeners. 
         [0102]    9. The apparatus of any preceding embodiment, wherein the longitudinal members are slidably attached to at least two of the transverse stiffeners. 
         [0103]    10. The apparatus of any preceding embodiment, wherein the transverse stiffeners are selected from one or more of a group of stiffeners consisting of: a bar; a metal slat; a stainless steel slat; an epoxy slat; a fiberglass slat; a carbon fiber reinforced epoxy slat; a plastic slat; a composite slat; and a wooden slat. 
         [0104]    11. The apparatus of any preceding embodiment, wherein the elastic sheet is selected from one or more of a group of elastic materials consisting of: a rubber; a polymer; an elastomer; and a material with a Young&#39;s modulus selected from a group of Young&#39;s moduli consisting of: ≦0.01 GPa, ≦0.1 GPa, ≦0.3 GPa, and ≦1.0 GPa. 
         [0105]    12. The apparatus of any preceding embodiment, wherein the longitudinal member is selected from a group of materials having a Young&#39;s modulus consisting of: ≧1.0 GPa, ≧3.0 GPa, ≧10.0 GPa, and ≧30.0 GPa. 
         [0106]    13. The apparatus of any preceding embodiment, wherein the wave energy conversion apparatus has a wave absorption efficiency selected from a group of absorption efficiencies consisting of: ≧40%; ≧60%; ≧80%; ≧90%; and ≧98%. 
         [0107]    14. A method of extracting wave energy, comprising: (a) providing one or more waves; (b) providing a wave energy conversion apparatus, comprising: (i) an absorber carpet comprising a first end and a second end; and (ii) a plurality of energy converters, each energy converter operatively coupled to the absorber carpet; (iii) wherein the wave that passes over the absorber carpet causes a movement of the absorber carpet, thereby operating one or more of the plurality of energy converters; and (c) extracting wave energy from the one or more waves with the wave energy conversion apparatus through operation of one or more of the plurality of energy converters. 
         [0108]    15. The method of any preceding embodiment, wherein the wave energy conversion apparatus has a wave energy efficiency selected from a group of efficiencies consisting of: ≧70%, ≧80%, ≧90%, ≧95%, and ≧98%. 
         [0109]    16. The method of any preceding embodiment, wherein extracting the wave energy comprises driving one or more of energy converters. 
         [0110]    17. The method of any preceding embodiment, wherein the wave substantially comprises fresh water or salt water. 
         [0111]    18. The method of any preceding embodiment, wherein at least one of the ends of the absorber carpet comprises: (a) one or more transverse stiffeners attached to an elastic sheet along a transverse extent; (b) one or more fasteners that fastens the elastic sheet to the one or more transverse stiffeners; (c) one or more through holes that pass through the one or more transverse stiffeners, as well as through the elastic sheet; and (d) one or more turnbuckles attached to the through hole at one end, and substantially fixed to a frame at another end; (e) wherein the turnbuckle tensions the elastic sheet. 
         [0112]    19. The method of any preceding embodiment, wherein one or more of the energy converters are selected from a group of pumps consisting of: a single acting pump; and a double acting pump. 
         [0113]    20. The method of any preceding embodiment, wherein the absorber carpet comprises: (a) an elastic sheet comprising a longitudinal and a transverse extent; (b) one or more transverse stiffeners connected to the elastic sheet along the transverse extent; and (c) one or more longitudinal members attached to at least two of the transverse stiffeners. 
         [0114]    21. The method of any preceding embodiment, wherein the longitudinal members are slidably attached to at least two of the transverse stiffeners. 
         [0115]    22. The method of any preceding embodiment, wherein the longitudinal members are selected from one or more of a group of members consisting of: a flexible member and a fiberglass bar. 
         [0116]    23. The method of any preceding embodiment, wherein the transverse stiffeners are selected from one or more of a group of stiffeners consisting of: a bar; a metal slat; a stainless steel slat; an epoxy slat; a fiberglass slat; a carbon fiber reinforced epoxy slat; a plastic slat; a composite slat; and a wooden slat. 
         [0117]    24. The method of any preceding embodiment, wherein the elastic sheet is selected from a group of elastic materials consisting of: a rubber, a polymer, and a material with a Young&#39;s modulus selected from a group of Young&#39;s moduli consisting of: ≦0.01 GPa, ≦0.1 GPa, ≦0.3 GPa, and ≦1.0 GPa. 
         [0118]    25. The method of any preceding embodiment, wherein the longitudinal member is selected from a group of materials having a Young&#39;s modulus consisting of: ≧1.0 GPa, ≧3.0 GPa, ≧10.0 GPa, and ≧30.0 GPa. 
         [0119]    26. A wave energy conversion apparatus, comprising: (a) an absorber carpet comprising a first end and a second end; (b) a plurality of energy converters, each energy converter coupled to the absorber carpet; and (c) means for extracting energy from a wave that interacts with the absorber carpet through operation of one or more of the plurality of energy converters. 
         [0120]    27. The apparatus of any preceding embodiment, wherein at least one of the ends of the absorber carpet comprises: (a) one or more transverse stiffeners attached to an elastic sheet along a transverse extent; (b) one or more fasteners that fastens the elastic sheet to the one or more transverse stiffeners; (c) one or more through holes that pass through the one or more transverse stiffeners, as well as through the elastic sheet; and (d) one or more turnbuckles attached to the through hole at one end, and substantially fixed to a frame at another end; (e) where the turnbuckle tensions the elastic sheet. 
         [0121]    28. The apparatus of any preceding embodiment, wherein one or more of the energy converters are selected from a group of energy converters consisting of: a single action hydraulic pump; a double action hydraulic pump; a linear electrical generator; a rack and pinion that drives a generator; and a rack and pinion that drives an alternator. 
         [0122]    29. The apparatus of any preceding embodiment, wherein one or more of the energy converters directly pressurize a source of water for reverse osmosis purification of the source of water into a purified water output. 
         [0123]    30. The apparatus of any preceding embodiment, wherein the absorber carpet comprises: (a) an elastic sheet comprising a longitudinal and a transverse extent; (b) one or more transverse stiffeners connected to the elastic sheet along the transverse extent; and (c) one or more longitudinal members attached to at least two of the transverse stiffeners. 
         [0124]    31. The apparatus of any preceding embodiment, wherein the longitudinal members are slidably attached to at least two of the transverse stiffeners. 
         [0125]    32. The apparatus of any preceding embodiment, wherein the longitudinal members are selected from one or more of a group of members consisting of: a flexible member and a fiberglass bar. 
         [0126]    33. The apparatus of any preceding embodiment, wherein the longitudinal members are selected from a group of materials having a Young&#39;s modulus consisting of: ≧1.0 GPa, ≧3.0 GPa, ≧10.0 GPa, and ≧30.0 GPa. 
         [0127]    34. The apparatus of any preceding embodiment, wherein the transverse stiffeners are selected from one or more of a group of stiffeners consisting of: a bar, an aluminum slat, a stainless steel slat, a fiberglass bar, a plastic slat, and a wooden slat. 
         [0128]    35. The apparatus of any preceding embodiment, wherein the elastic sheet is selected from a group of elastic materials comprising: a rubber, a polymer, and a material with a Young&#39;s modulus selected from a group of Young&#39;s moduli consisting of: ≦0.01 GPa, ≦0.1 GPa, ≦0.3 GPa, and ≦1.0 GPa. 
         [0129]    36. The apparatus of any preceding embodiment, wherein the longitudinal member is selected from a group of materials having a Young&#39;s modulus consisting of: ≧1.0 GPa, ≧3.0 GPa, ≧10.0 GPa, and ≧30.0 GPa. 
         [0130]    37. The apparatus of any preceding embodiment, wherein the means for extracting energy from the wave has a wave energy efficiency selected from a group of efficiencies consisting of: ≧70%, ≧80%, ≧90%, ≧95%, and ≧98%. 
         [0131]    38. The apparatus of any preceding embodiment, wherein the means for extracting energy from the wave comprises: (a) a frame movably attached to the first and second ends of the absorber carpet; (b) one or more attachments to a moor point on a moored end, and to the frame on another end; and (c) the moor point selected from a group of moor points consisting of: a floor of a body of water; a platform connected to one or more footings in a floor of a body of water; and a floating platform. 
         [0132]    39. The apparatus of any preceding embodiment, wherein: (a) the attachments allow for movement of the frame from below a surface of the body of water to the surface of the body of water; and (b) wherein the wave propagates within the body of water. 
         [0133]    40. The apparatus of any preceding embodiment, wherein the means for extracting energy comprises: (a) a frame; and (b) one or more energy converters movably attached to the frame at a frame end, and to the absorber carpet at a carpet end. 
         [0134]    41. A wave energy conversion apparatus, comprising: (a) an absorber carpet comprising a first end and a second end; and (b) a plurality of pumps, each pump operatively coupled to the absorber carpet; (c) wherein a wave that passes over the absorber carpet causes a movement of the absorber carpet, thereby operating one or more of the plurality of pumps. 
         [0135]    42. The apparatus of any preceding embodiment, wherein at least one of the ends of the absorber carpet comprises: (a) one or more transverse stiffeners attached to an elastic sheet along a transverse extent; (b) one or more fasteners that fastens the elastic sheet to the one or more transverse stiffeners; (c) one or more through holes that pass through the one or more transverse stiffeners, as well as through the elastic sheet; and (d) one or more turnbuckles attached to the through hole at one end, and substantially fixed to a frame at another end; (e) wherein the turnbuckle tensions the elastic sheet. 
         [0136]    43. The apparatus of any preceding embodiment, wherein one or more of the pumps are double acting. 
         [0137]    44. The apparatus of any preceding embodiment, wherein the absorber carpet comprises: (a) an elastic sheet comprising a longitudinal and a transverse extent; (b) one or more transverse stiffeners connected to the elastic sheet along the transverse extent; (c) one or more longitudinal members attached to at least two of the transverse stiffeners. 
         [0138]    45. The apparatus of any preceding embodiment, wherein the longitudinal members are slidably attached to at least two of the transverse stiffeners. 
         [0139]    46. The apparatus of any preceding embodiment, wherein the longitudinal members are selected from one or more of a group of members consisting of: a flexible member and a fiberglass bar. 
         [0140]    47. The apparatus of any preceding embodiment, wherein the transverse stiffeners are selected from one or more of a group of stiffeners consisting of: a bar, an aluminum slat, a stainless steel slat, a fiberglass bar, a plastic slat, and a wooden slat. 
         [0141]    48. The apparatus of any preceding embodiment, wherein the elastic sheet is selected from a group of elastic materials comprising: a rubber, a polymer, and a material with a Young&#39;s modulus selected from a group of Young&#39;s moduli consisting of: ≦0.01 GPa, ≦0.1 GPa, and ≦0.3 GPa. 
         [0142]    49. The apparatus of any preceding embodiment, wherein the longitudinal member is selected from a group of materials having a Young&#39;s modulus consisting of: ≧1.0 GPa, ≧3.0 GPa, ≧10.0 GPa, and ≧30.0 GPa. 
         [0143]    50. The apparatus of any preceding embodiment, wherein the wave energy conversion apparatus has a wave energy efficiency selected from a group of efficiencies consisting of: ≧70%, ≧80%, ≧90%, ≧95%, and ≧98%. 
         [0144]    51. A method of extracting wave energy, comprising: (a) providing one or more waves; (b) providing a wave energy conversion apparatus, comprising: (i) an absorber carpet comprising a first end and a second end; and (ii) a plurality of pumps, each pump operatively coupled to the absorber carpet; (iii) wherein the wave that passes over the absorber carpet causes a movement of the absorber carpet, thereby operating one or more of the plurality of pumps; (c) extracting wave energy from the one or more waves with the wave energy conversion apparatus through operation of one or more of the plurality of pumps. 
         [0145]    52. The method of any preceding embodiment, wherein the wave energy conversion apparatus has a wave energy efficiency selected from a group of efficiencies consisting of: ≧70%, ≧80%, ≧90%, ≧95%, and ≧98. 
         [0146]    53. The method of any preceding embodiment, wherein the extracting the wave energy step comprises pumping a fluid via the one or more of the plurality of pumps. 
         [0147]    54. The method of any preceding embodiment, wherein the fluid is a medium of the one or more waves. 
         [0148]    55. The method of any preceding embodiment, wherein at least one of the ends of the absorber carpet comprises: (a) one or more transverse stiffeners attached to an elastic sheet along a transverse extent; (b) one or more fasteners that fastens the elastic sheet to the one or more transverse stiffeners; (c) one or more through holes that pass through the one or more transverse stiffeners, as well as through the elastic sheet; and (d) one or more turnbuckles attached to the through hole at one end, and substantially fixed to a frame at another end; (e) wherein the turnbuckle tensions the elastic sheet. 
         [0149]    56. The method of any preceding embodiment, wherein one or more of the pumps are double acting. 
         [0150]    57. The method of any preceding embodiment, wherein the absorber carpet comprises: (a) an elastic sheet comprising a longitudinal and a transverse extent; (b) one or more transverse stiffeners connected to the elastic sheet along the transverse extent; (c) one or more longitudinal members attached to at least two of the transverse stiffeners. 
         [0151]    58. The method of any preceding embodiment, wherein the longitudinal members are slidably attached to at least two of the transverse stiffeners. 
         [0152]    59. The method of any preceding embodiment, wherein the longitudinal members are selected from one or more of a group of members consisting of: a flexible member and a fiberglass bar. 
         [0153]    60. The method of any preceding embodiment, wherein the transverse stiffeners are selected from one or more of a group of stiffeners consisting of: a bar, an aluminum slat, a stainless steel slat, a fiberglass bar, a plastic slat, and a wooden slat. 
         [0154]    61. The apparatus of any preceding embodiment, wherein the elastic sheet is selected from a group of elastic materials comprising: a rubber, a polymer, and a material with a Young&#39;s modulus selected from a group of Young&#39;s moduli consisting of: ≦0.01 GPa, ≦0.1 GPa, and ≦0.3 GPa. 
         [0155]    62. The apparatus of any preceding embodiment, wherein the longitudinal member is selected from a group of materials having a Young&#39;s modulus consisting of: ≧1.0 GPa, ≧3.0 GPa, ≧10.0 GPa, and ≧30.0 GPa. 
         [0156]    63. A wave energy conversion apparatus, comprising: (a) an absorber carpet comprising a first end and a second end; and (b) a plurality of pumps, each pump operatively coupled to the absorber carpet; (c) means for extracting energy from a wave that passes over the absorber carpet through operation of one or more of the plurality of pumps. 
         [0157]    64. The apparatus of any preceding embodiment wherein at least one of the ends of the absorber carpet comprises: (a) one or more transverse stiffeners attached to an elastic sheet along a transverse extent; (b) one or more fasteners that fastens the elastic sheet to the one or more transverse stiffeners; (c) one or more through holes that pass through the one or more transverse stiffeners, as well as through the elastic sheet; and (d) one or more turnbuckles attached to the through hole at one end, and substantially fixed to a frame at another end; (e) wherein the turnbuckle tensions the elastic sheet. 
         [0158]    65. The apparatus of any preceding embodiment, wherein one or more of the plurality of pumps are double acting. 
         [0159]    66. The apparatus of any preceding embodiment, wherein the absorber carpet comprises: (a) an elastic sheet comprising a longitudinal and a transverse extent; (b) one or more transverse stiffeners connected to the elastic sheet along the transverse extent; (c) one or more longitudinal members attached to at least two of the transverse stiffeners. 
         [0160]    67. The apparatus of any preceding embodiment, wherein the longitudinal members are slidably attached to at least two of the transverse stiffeners. 
         [0161]    68. The apparatus of any preceding embodiment, wherein the longitudinal members are selected from one or more of a group of members consisting of: a flexible member and a fiberglass bar. 
         [0162]    69. The apparatus of any preceding embodiment, wherein the transverse stiffeners are selected from one or more of a group of stiffeners consisting of: a bar, an aluminum slat, a stainless steel slat, a fiberglass bar, a plastic slat, and a wooden slat. 
         [0163]    70. The apparatus of any preceding embodiment, wherein the elastic sheet is selected from a group of elastic materials comprising: a rubber, a polymer, and a material with a Young&#39;s modulus selected from a group of Young&#39;s moduli consisting of: ≦0.01 GPa, ≦0.1 GPa, and ≦0.3 GPa. 
         [0164]    71. The apparatus of any preceding embodiment, wherein the longitudinal member is selected from a group of materials having a Young&#39;s modulus consisting of: ≧1.0 GPa, ≧3.0 GPa, ≧10.0 GPa, and ≧30.0 GPa. 
         [0165]    72. The apparatus of any preceding embodiment, wherein the means for extracting energy from the wave has a wave energy efficiency selected from a group of efficiencies consisting of: ≧70%, ≧80%, ≧90%, ≧95%, and ≧98%. 
         [0166]    73. The apparatus of any preceding embodiment, wherein the means for extracting energy from the wave comprises: (a) a frame movably attached to the first and second ends of the absorber carpet; (b) one or more attachments to a floor of a body of water on a moored end, and to the frame on the other end. 
         [0167]    74. The apparatus of any preceding embodiment, wherein the attachments allow for movement of the frame from the floor of the body of water to a surface of the body of water. 
         [0168]    75. The apparatus of any preceding embodiment, wherein the means for extracting energy comprises: (a) a frame; (b) each pump movably attached to the frame at a frame end, and to the absorber carpet at a carpet end. 
         [0169]    Although the description above contains many details, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Therefore, it will be appreciated that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” All structural, chemical, and functional equivalents to the elements of the above-described preferred embodiment that are known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed as a “means plus function” element unless the element is expressly recited using the phrase “means for”. No claim element herein is to be construed as a “step plus function” element unless the element is expressly recited using the phrase “step for”.