Attenuators wave energy

Click to learn more about the history behind our wave attenuation devices. Our breakwater devices are constructed of linear low density molded polyethylene with a high density polyethylene tubular core. The interior is hollow which is filled with water at installation until the units are two-thirds submerged.

The exterior has a series of baffles that agitate back and forth as the waves strike the system. When engineering a wave attenuation system we take into account the wave length, distance crest to crestwave height, water depth and fetch distance. Based on those aquatic specifications, we can design a breakwater system encompassing your specific needs.

Installations in the US and various other countries have been designed for protecting marinas, boat launch facilities, utility spillways, shore erosion prevention and even floating breakwater for fish farms. Explore our many wave attenuation case studies. Since Wave Eater is comprised of plastic and filled with water it's "footprint" on the environment is minimal, thereby allowing for an expedited processing when design and installation permits are required.

How Floating Breakwaters Work 1 Wave Eater is an innovative, convenient, floating breakwater system designed for various waterfront applications that is both easy to install and environmentally safe. Our Wave Attenuator System 2 Wave Eater's innovative design allows for a number of different configurations based on the amount of wave dissipation the removal of wave height and energy required, as it passes through the attenuator.

Click to See Wave Eater in action. Wave Eater Protection 3 Our product provides a means of protection that is both economical and functional. Explore our many wave attenuation case studies Since Wave Eater is comprised of plastic and filled with water it's "footprint" on the environment is minimal, thereby allowing for an expedited processing when design and installation permits are required.

Contact Wave Eater Phone: Email: info waveeater. All rights reserved.

attenuators wave energy

Wave Eater is made in the U. A and uses recycled materials. Wave Eater Floating Breakwater Systems Providing industry-leading floating breakwater and wave attenuation devices since 4.Wave energy or wave power is the transport and capture of energy by ocean surface waves.

The energy captured is then used for all different kinds of useful work, including electricity generation, water desalination, and pumping of water. Wave energy is also a type of renewable energy and is the largest estimated global resource form of ocean energy. The first patent in wave energy happened in Paris in Monsieur Girard and his son proposed using direct mechanical action to drive heavy machinery, including mills, saws, and pumps. There were from to in the UK alone.

Another early application was in Bochaux Praceique developed a device to light and power his house.

attenuators wave energy

This application was also in France. The pioneer for modern wave energy was Yoshio Masuda, a Japanese naval commander. Masuda tested multiple different wave-energy devices at sea, and several hundred of these units were used to power navigation lights. Masuda is also credited for different wave-energy inventions, such as the KAIMEI, a large barge used as a testing platform, and the Oscillating Water Column, which was initially used for small-scale navigation.

Wave energy got a new interest in the s during the oil crisis on Inmember of the Organization of Arab Petroleum Exporting Countries OAPEC decided to put a prohibition on oil exports, which in turn caused people to look for alternative energies.

There are multiple different technologies used for Wave energy. There are five main types of technology used including; Absorbers, Attenuators, Oscillation water columns, overtopping and Inverted- Pendulum device. Abosorbers extract energy from the rise and fall of the waves with a buoy. Once the energy is extracted it is then converted to electrical energy with a linear or rotary generator.

Jamaica Bay Wave Attenuators

Attenuators capture energy by being placed perpendicular to the length of the wave, this causes the attenuator to contentiously flex where segments are connected. This connection is then connected to hydraulic pumps which convert the energy.Wave power is the capture of energy of wind waves to do useful work — for example, electricity generationwater desalinationor pumping water.

A machine that exploits wave power is a wave energy converter WEC. Wave power is distinct from tidal powerwhich captures the energy of the current caused by the gravitational pull of the Sun and Moon. Waves and tides are also distinct from ocean currents which are caused by other forces including breaking waveswindthe Coriolis effectcabbelingand differences in temperature and salinity. Wave-power generation is not a widely employed commercial technology compared to other established renewable energy sources such as wind powerhydropower and solar power.

However, there have been attempts to use this source of energy since at least [1] mainly due to its high power density. Whereas, the average annual power density of the waves at e. Waves are generated by wind passing over the surface of the sea. As long as the waves propagate slower than the wind speed just above the waves, there is an energy transfer from the wind to the waves.

Both air pressure differences between the upwind and the lee side of a wave crestas well as friction on the water surface by the wind, making the water to go into the shear stress causes the growth of the waves.

Wave height is determined by wind speed, the duration of time the wind has been blowing, fetch the distance over which the wind excites the waves and by the depth and topography of the seafloor which can focus or disperse the energy of the waves. A given wind speed has a matching practical limit over which time or distance will not produce larger waves.

When this limit has been reached the sea is said to be "fully developed". In general, larger waves are more powerful but wave power is also determined by wave speed, wavelengthand water density. Oscillatory motion is highest at the surface and diminishes exponentially with depth. However, for standing waves clapotis near a reflecting coast, wave energy is also present as pressure oscillations at great depth, producing microseisms.

The waves propagate on the ocean surface, and the wave energy is also transported horizontally with the group velocity. The mean transport rate of the wave energy through a vertical plane of unit width, parallel to a wave crest, is called the wave energy flux or wave power, which must not be confused with the actual power generated by a wave power device.

In deep water where the water depth is larger than half the wavelengththe wave energy flux is [a].

How Is Wave Energy Used to Generate Electricity?

The above formula states that wave power is proportional to the wave energy period and to the square of the wave height. When the significant wave height is given in metres, and the wave period in seconds, the result is the wave power in kilowatts kW per metre of wavefront length.

Example: Consider moderate ocean swells, in deep water, a few km off a coastline, with a wave height of 3 m and a wave energy period of 8 s. Using the formula to solve for power, we get.

In major storms, the largest waves offshore are about 15 meters high and have a period of about 15 seconds. According to the above formula, such waves carry about 1. An effective wave power device captures as much as possible of the wave energy flux.

As a result, the waves will be of lower height in the region behind the wave power device. In a sea statethe average mean energy density per unit area of gravity waves on the water surface is proportional to the wave height squared, according to linear wave theory: [6] [11].

The potential energy density is equal to the kinetic energy, [6] both contributing half to the wave energy density Eas can be expected from the equipartition theorem.

In ocean waves, surface tension effects are negligible for wavelengths above a few decimetres. As the waves propagate, their energy is transported. The energy transport velocity is the group velocity.In physicsattenuation or, in some contexts, extinction is the gradual loss of flux intensity through a medium.

For instance, dark glasses attenuate sunlightlead attenuates X-raysand water and air attenuate both light and sound at variable attenuation rates. Hearing protectors help reduce acoustic flux from flowing into the ears.

This phenomenon is called acoustic attenuation and is measured in decibels dBs. In electrical engineering and telecommunicationsattenuation affects the propagation of waves and signals in electrical circuitsin optical fibersand in air. Electrical attenuators and optical attenuators are commonly manufactured components in this field.

In many cases, attenuation is an exponential function of the path length through the medium. In chemical spectroscopythis is known as the Beer—Lambert law.

One area of research in which attenuation plays a prominent role, is in ultrasound physics. Attenuation in ultrasound is the reduction in amplitude of the ultrasound beam as a function of distance through the imaging medium. Accounting for attenuation effects in ultrasound is important because a reduced signal amplitude can affect the quality of the image produced. By knowing the attenuation that an ultrasound beam experiences traveling through a medium, one can adjust the input signal amplitude to compensate for any loss of energy at the desired imaging depth.

Wave equations which take acoustic attenuation into account can be written on a fractional derivative form, see the article on acoustic attenuation or e. Attenuation coefficients are used to quantify different media according to how strongly the transmitted ultrasound amplitude decreases as a function of frequency.

Attenuation is linearly dependent on the medium length and attenuation coefficient, as well as — approximately — the frequency of the incident ultrasound beam for biological tissue while for simpler media, such as air, the relationship is quadratic. Attenuation coefficients vary widely for different media. In biomedical ultrasound imaging however, biological materials and water are the most commonly used media. There are two general ways of acoustic energy losses: absorption and scatteringfor instance light scattering.

Propagation through heterogeneous media requires taking into account scattering. When the Sun's radiation reaches the sea surface, the shortwave radiation is attenuated by the water, and the intensity of light decreases exponentially with water depth. The intensity of light at depth can be calculated using the Beer-Lambert Law. In clear mid-ocean waters, visible light is absorbed most strongly at the longest wavelengths. Thus, red, orange, and yellow wavelengths are totally absorbed at shallower depths, while blue and violet wavelengths reach deeper in the water column.

Because the blue and violet wavelengths are absorbed least compared to the other wavelengths, open-ocean waters appear deep blue to the eye. Near the shore, coastal water contains more phytoplankton than the very clear mid-ocean waters. Chlorophyll -a pigments in the phytoplankton absorb light, and the plants themselves scatter light, making coastal waters less clear than mid-ocean waters.

Chlorophyll-a absorbs light most strongly in the shortest wavelengths blue and violet of the visible spectrum. In coastal waters where high concentrations of phytoplankton occur, the green wavelength reaches the deepest in the water column and the color of water appears blue-green or green. The energy with which an earthquake affects a location depends on the running distance.

The attenuation in the signal of ground motion intensity plays an important role in the assessment of possible strong groundshaking. A seismic wave loses energy as it propagates through the earth attenuation. This phenomenon is tied into the dispersion of the seismic energy with the distance. There are two types of dissipated energy:.Commercial waterfront property and equipment is often susceptible to excessive wave action.

We custom fabricate our wave attenuators as either a separate system or integrated into your commercial marina dock system. Using the wave attenuator as part of the dock system provides the advantage of additional slip space along with increasing revenue. Our galvanized steel wave attenuator is fabricated using a steel truss substructure.

The system will be designed based on your site depending on the wind and wave exposure. Using our superior connection, anchoring and hinge systems, our wave attenuator is designed to withstand severe wave action. We have had years of experience designing, fabricating and installing commercial systems in often challenging locations. Our commitment to quality and our experienced professional staff are the keys to our success.

For a free quote on your project, simply complete our online site survey or download a printable one and one of our waterfront specialists will contact you. Skip Navigation. Residential Docks Stock Docks readily available.

Municipalities, Resorts, Summer Camps. Boat Lifts Vertical Boat Lifts. Small Craft Lifts for non-motorized crafts. Residential Floating Launch Systems. Marine Construction Marine and Waterfront Construction. Home Contact Us. Residential Docks. Dock Accessories. Boat Lifts. Marine Construction. Shop Online. Wave Attenuators Steel truss wave attenuators designed to withstand severe wave action. Sealed polyethylene floatation units are bolted inside structure, protected from waves and ice Unsinkable design — no hollow floatation devices Superior anchoring, connection and hinge systems Cost-effective epoxy painted systems are available versus standard galvanized We will design your wave attenuator to provide maximum comfort and security for your facility and boat owners Quote Request Free Catalogs.

Email Us Tel: Fax: The bulk of electricity that powers the industrial world comes from induction generators. The first one came online in and was powered by the falling cascade of water that is Niagara Falls. Most modern induction generators are steam-driven, though, and the fuels of choice to heat the water have long been been coil, petroleum and natural gas — so-called fossil fuels.

As offossil fuels supplied 82 percent of the world's electricity, but evidence continues to mount of the devastating effects the byproducts of combustion have on the environment. As of Octoberscientists were warning that global warming, to which fossil fuel combustion is a prime contributor, was quickly approaching an irreversible tipping point.

The result of such warnings is a shift away from fossil fuels and toward renewable energy sources, such as photovoltaic panels, geothermal energy and wind turbines. Wave power is one of the options on the table. The oceans represent a vast reservoir of untapped energy. That's enough energy to power to 2. Another way to look at it is that a single wave has enough energy to power an electric car for hundreds of miles.

Four main technologies exist to harness wave energy. Some work near the shore, some offshore and some in the deep sea. Wave energy converters WECs are designed to remain on the surface of the water, but they differ in the orientations of the collectors to the movement of the waves and in the methods used to generate electricity. The four types of wave electricity generators are point absorbers, terminators, overtopping devices and attenuators.

Believe it or not, wave power is another form of solar energy. The sun heats different parts of the globe to different extents, and the resulting temperature differences create the winds that interact with the ocean water to create waves. Solar radiation also creates temperature differences in the water itself, and these drive underwater currents.

It may be possible to harness the energy of these currents in the future, but for now, most of the attention of the energy industry has been focused on surface waves. In a hydroelectric dam, the energy of falling water directly spins the turbines that generate AC electricity. This principle is used almost unaltered in some forms of wave generation, but in others, the energy of the rising and falling water has to pass through another medium before it can do the work of spinning the turbine.

This medium is often air. The air is sealed in a chamber, and the motion of the waves compresses it. The compressed air is then forced through a small aperture, creating a jet of air that can do the necessary work.

In some technologies, the energy of the waves is transferred to mechanical energy by hydraulic pistons.Power Curves. Cost Estimations.

attenuators wave energy

The Team Acknowledgements. Ocean Power Delivery is developing a freely floating hinged contour device. The device looks like a snake, floating on the ocean surface. The device consists of 4 tubular sections, connected by 3 hinges.

Wave Energy

The 4 sections move relative to each other and the hinges convert this motion by means of a digitally controlled hydraulic power conversion system.

The total device length is m, with a tube diameter of 4. A full-scale pre-production prototype has been built and is currently undergoing sea-trials off the coast of Scotland. Structural Elements The structure is a steel structure that can be built locally using standard construction techniques available at most shipyards.

The device structure has been designed using standard offshore construction principles, and a leading offshore technology consulting firm independently verified the design. Power Take Off Each hinge of the device contains its own hydraulic power take off.

Each power take off has a total of 3 hydraulic rams, which convert the motions into hydraulic pressure. Using accumulators and two kW generator sets, the hydraulic power is generating electricity.

The hinges and power conversion mechanism have undergone full scale testing on a test-rig and have been integrated into the full-scale device. The mooring allows the device to turn into wave direction within its mooring constraints.

The mooring and survivability of the system has been simulated theoretically and tested in wave tanks. While the mooring is probably the least mature element in the overall system and will need to be looked at closely and adapted to the specific site requirements, it does not raise any concerns.

The mooring and survivability has been independently analysed and verified by one of the leading offshore technology consultancy firms and is designed to withstand the year storm wave.

Source: Pelamis Wave Power. As such, it is able to completely synchronize with the wave farm transmission voltage.

Wave Energy Converters

A flexible riser cable connects the surface device to a junction box sitting on the ocean floor. Installation The device is designed with quick deployment and recovery in mind. The power and three mooring connections can be quickly disconnected from a tug, the devices nose attached to a special harness and towing can begin.

This approach requires a minimal amount of time spent offshore and will reduce the weather windows required to deploy or recover the device. The slender and long steel structure, will allow for a simple towing-operation using a single handler tug. Performance The device is able to rapidly tune to the incident wave climate using a digitally controlled hydraulic system and detune to over-sized waves.

A large amount of effort has gone into optimizing the devices tuning and associated efficiency. Being a relatively narrow device, which will point into the wave and is able to completely de-adjust to large waves, it will always minimize loads on its mooring system.

The power take off and control subsystems have been designed with many redundancies in place to minimize reactive maintenance such as the required intervention after a storm. The estimated life duration of this device is 15 years. Many subsystems, such as power modules, are designed in such a way that they can be lifted out with a crane and replaced with a tested subsystem. The company has demonstrated technical capability by taking this device from concept to full-scale using a rigorous approach of eliminating and testing at the appropriate scale.

Depending on the volume, most of the electrical and hydraulic machine elements can also be sourced from US sources.


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