What is Wave Energy?Waves are the most concentrated form of solar energy. The Sun makes the wind blow. Wavesare generated by the wind as it blows across the sea surface. Energy is transferred from thewind to the waves.The energy within a wave is proportional to the square of the wave height, so a two-meter highwave has four times the power of a one-meter high wave.Wave power varies considerably in different parts of the world, and wave energy cant beharnessed effectively everywhere. These regions are generally found in the temperate zones(30-60 degrees latitude north and south of the equator). Wave-power rich areas of the worldinclude the western coasts of Europe, northern Canada, southern Africa, Australasia, and thenorthwestern coasts of the United States.
ObjectivesTo provide a wave energy convertor device which alleviates all deficiencies associated withother ocean wave energy technologies.To provide a device for generating electrical energy using ocean waves which is easy to install &maintain, reliable & economical to operate, converts maximum wave energy and can sustainextreme ocean conditions.To provide a device for generating electrical energy using ocean waves which is of reasonablesize and requires less space for installation.To provide a device for generating electrical energy using ocean waves which generateselectricity at its full rated capacity during extreme conditions without the need for a shutdownto keep up the overall capacity factor.
Device StructureMulti-body mechanical device for generating electrical energy using ocean waves, comprising:A tunnel like structure having two ends being named as first end and second end.A pair of fixed floats being attached on each side of the first end of tunnel like structure.A pair of articulated floats being attached on each side of the first end of tunnel like structure.A turbine inside the tunnel like structure comprising of a rotating shaft and a unidirectionalrotor.A direct drive generator being provided at the first end of tunnel like structure.Anticipated size for a 1 MW system is - Column tunnel diameter: 10 Meters, Total length 50Meters and Total width 30 Meters.
Device WorkingOnce the floating device is installed offshore in the ocean, the passing waves transfer motion tothe articulated and fixed floats.The movement of fixed and articulated floats in turn provide the driving force to move thetunnel like structure up and down.The up and down movement of the tunnel like structure enables the water column inside it tooscillate in reference and the resulting forces drive the unidirectional turbine to rotate the directdrive generator in one direction only.
Advantages – Invention v/s ExistingIts unique Articulated Floats help in capturing more energy from both components of wave.Extra capture width of fixed floats also mean even further more transfer of wave energy.Its articulated floats self-adjust the natural frequency to irregular wave conditions, which notonly helps to converge more power captured to run the turbine inside the tunnel (more energyabsorption) but will also detune itself automatically and ride the huge waves safely understormy conditions (better survivability)No need for shut down under any conditions as the PTO cannot exceed its maximum rated RPMby virtue of its design (more capacity factor). Also No rigid connections to the PTO, hence doesnot suffer from end-stop issue which mostly poses damage to systems in extreme conditions.Simple construction design with minimal moving parts. No gear box, hence no expensivebreakdowns. Transmission of pure torque to the direct drive generator (much better efficiency)Normal, minimal routine maintenance and lesser operating costs. No cavitation problem asturbine located in deep water (counteracted by positive pressure on the turbine blades)Lower infrastructure cost associated for a wave farm (lesser power conditioning systemsrequired for grid compliance)Lower anchorage and mooring costs. Slack mooring allows the device to self orient in thepredominant wave direction.
Unique Selling Proposition The main USP of the device is the Uniturbine (Unidirectional Turbine) PTO which directly uses water column to run the turbine as against all other Oscillation Water Columns (OWCs) using air. This novel design lets the device capture more energy - many times over, utilising the advantage of high density of water and its incompressible nature as compared to air, for the same diameter of turbine. More reliability as compared to There is no need for shut down hydraulic based PTO and under any condition as smoother power compared to Uniturbine can not exceed its other devices. The design of the maximum rated RPM by virtue of turbine is kept simple to make it its design. Thus keeping the cost effective, efficient and overall capacity factor up to its reliable. maximum achievable.
Development StagesPCT application published on WIPO website with all 8 claims passed for Novelty, Inventive step &Industrial applicability by ISAStage-1 Proposal received after appraisal to develop the technology from one of the worlds largestconsultants on Marine EnergyApproximate funding required from Simulation to Commercial = USD/GBP 8.0 Million3+ years to roll out the full scale Prototype Design & Trial CommercialSimulation Testing Development
Wave Energy Industry
Why Wave Energy?Waves originate from storms far out in sea and can travel long distances without significantenergy loss, power produced from them is much steadier and more predictable, both day to dayand season to season. This reduces project risk;Unlike wind and solar power, power from ocean waves continues to be produced around theclock, whereas wind velocity tends to die in the morning and at night, and solar is only availableduring the day in areas with relatively little cloud cover;Wave energy contains roughly 1000 times the kinetic energy of wind, allowing much smallerand less conspicuous devices to produce the same amount of power in a fraction of the space;Wave power production is much smoother and more consistent than wind or solar, resulting inhigher overall capacity factors;Wave energy varies as the square of wave height, whereas wind power varies with the cube ofair speed. Water being 850 times as dense as air, results in much higher power production fromwaves averaged over time.
Global Wave Energy Averages Average wave energy (est.) in kW/m (kW per meter of wave length)
Wave Energy- PotentialWorldwide theoretical potential of 44,000 TWh/year estimated conservatively by IEA(International Energy Agency)200,000 MW installed wave and tidal energy power forecast by 2050, DTI & Carbon Trust (UK)Wave energy resource of 50 Twh/y in UK alone which represents 12.4% of their ElectricityGeneration, DECC (UK)
Wave Energy Power Distribution
Ocean Wave Energy TechnologiesA variety of technologies have been proposed to capture the energy from waves. Some of thepromising designs that are undergoing demonstration testing at near-commercial stages.1. Terminators2. Floating Point Absorbers3. Attenuators4. Overtopping Device
1. TerminatorsTerminator devices extend perpendicular to the direction of wave travel and capture or reflectthe power of the wave. These devices are typically onshore or nearshore; however, floatingversions have been designed for offshore applications.
2. Floating Point AbsorbersA point absorber is a floating structure with components that move relative to each other dueto wave action. The relative motion is used to drive electromechanical or hydraulic energyconverters.
3. AttenuatorsAttenuators are long multi-segment floating structures oriented parallel to the direction of thewaves. The differing heights of waves along the length of the device causes flexing where thesegments connect, and this flexing is connected to hydraulic pumps or other converters.
4. Overtopping DeviceOvertopping devices have reservoirs that are filled by incoming waves to levels above theaverage surrounding ocean. The water is then released, and gravity causes it to fall backtoward the ocean surface. The energy of the falling water is used to turn hydro turbines.
Prominent Companies in Wave Energy
Ocean Technology Maturity Curves
PotentialThe realistically usable worldwide resource has been estimated to be greater than 2 TW.Locations with the most potential for wave power include the western seaboard of Europe, thenorthern coast of the UK, and the Pacific coastlines of North and South America, SouthernAfrica, Australia, and New Zealand.The north and south temperate zones have the best sites for capturing wave power. Theprevailing westerlies in these zones blow strongest in winter.
Wave Energy MarketThe realizable potential for wave and tidal together is estimated to be a maximum of about25% of the total world demand for electricity, though the theoretical potential is much higher.In terms of market value, the potential market for wave energy is worth about $1 trillionworldwide, according to the World Energy Council. In the United States alone, wave technologycould supply 6.5 percent of the nations energy.There have been estimates that investments of over ₤500 billion would be necessary for waveenergy to contribute 2000 TWh per year worldwide. This is broadly equivalent to the existingdeployed markets for nuclear and hydroelectric power.Wave energy technologies are the most heavily researched and funded sector in the oceanpower industry, enabling companies to create lucrative opportunities when compared with othersectors of the energy industry which are more mature.At present there is little design consensus for wave energy devices with no industry standarddevice concept. Due to the diverse nature of the wave resource it appears unlikely that therewill be one single device concept that is used.Wave energy industry today is in its infancy, when wind was also about the same 20 years ago,and now poised to grow just as huge.
Targets for Ocean Energy - Europe
Why to invest in Wave Energy?Analysis of global supply of conventional fossil fuels, such as oil and gas, reveals that depositsare dwindling, and their prices are increasing. It is predicted that renewable energy sources,including wave, will fill the resultant vacuum.Demand side analysis shows positive indicators, both for global energy demand as well asglobal renewable energy demand. Forecast demands for wave energy, which are specified bytargets, are also healthy. Capex has reduced for most renewables with time, due to learning curves.Although costs can be a considerable barrier, much effort has been made by nationalgovernments to provide support mechanisms for the young wave energy industry. Supportmechanisms consist of feed-in tariffs, grants and national targets. The drivers for policy makersin government to provide these support mechanisms are many and encouraging for the waveenergy investor.