Posts Tagged ‘OWC’

JAMES RICKMAN, Seeking Alpha, June 8, 2009

wave-ocean-blue-sea-water-white-foam-photoOceans cover more than 70% of the Earth’s surface. As the world’s largest solar collectors, oceans generate thermal energy from the sun. They also produce mechanical energy from the tides and waves. Even though the sun affects all ocean activity, the gravitational pull of the moon primarily drives the tides, and the wind powers the ocean waves.

Wave energy is the capture of the power from waves on the surface of the ocean. It is one of the newer forms of renewable or ‘green’ energy under development, not as advanced as solar energy, fuel cells, wind energy, ethanol, geothermal companies, and flywheels. However, interest in wave energy is increasing and may be the wave of the future in coastal areas according to many sources including the International Energy Agency Implementing Agreement on Ocean Energy Systems (Report 2009).

Although fewer than 12 MW of ocean power capacity has been installed to date worldwide, we find a significant increase of investments reaching over $2 billion for R&D worldwide within the ocean power market including the development of commercial ocean wave power combination wind farms within the next three years.

Tidal turbines are a new technology that can be used in many tidal areas. They are basically wind turbines that can be located anywhere there is strong tidal flow. Because water is about 800 times denser than air, tidal turbines will have to be much sturdier than wind turbines. They will be heavier and more expensive to build but will be able to capture more energy. For example, in the U.S. Pacific Northwest region alone, it’s feasible that wave energy could produce 40–70 kilowatts (kW) per meter (3.3 feet) of western coastline. Renewable energy analysts believe there is enough energy in the ocean waves to provide up to 2 terawatts of electricity.

Companies to Watch in the Developing Wave Power Industry:

Siemens AG (SI) is a joint venture partner of Voith Siemens Hydro Power Generation, a leader in advanced hydro power technology and services, which owns Wavegen, Scotland’s first wave power company. Wavegen’s device is known as an oscillating water column, which is normally sited at the shoreline rather than in open water. A small facility is already connected to the Scottish power grid, and the company is working on another project in Northern Spain.

Ocean Power Technologies, Inc (OPTT) develops proprietary systems that generate electricity through ocean waves. Its PowerBuoy system is used to supply electricity to local and regional electric power grids. Iberdrola hired the company to build and operate a small wave power station off Santona, Spain, and is talking with French oil major Total (TOT) about another wave energy project off the French coast. It is also working on projects in England, Scotland, Hawaii, and Oregon.

Pelamis Wave Power, formerly known as Ocean Power Delivery, is a privately held company which has several owners including various venture capital funds, General Electric Energy (GE) and Norsk Hydro ADR (NHYDY.PK). Pelamis Wave Power is an excellent example of Scottish success in developing groundbreaking technology which may put Scotland at the forefront of Europe’s renewable revolution and create over 18,000 green high wage jobs in Scotland over the next decade. The Pelamis project is also being studied by Chevron (CVX).

Endesa SA ADS (ELEYY.PK) is a Spanish electric utility which is developing, in partnership with Pelamis, the world’s first full scale commercial wave power farm off Aguçadoura, Portugal which powers over 15,000 homes. A second phase of the project is now planned to increase the installed capacity from 2.25MW to 21MW using a further 25 Pelamis machines.

RWE AG ADR (RWEOY.PK) is a German management holding company with six divisions involved in power and energy. It is developing wave power stations in Siadar Bay on the Isle of Lewis off the coast of Scotland.

Australia’s Oceanlinx offers an oscillating wave column design and counts Germany’s largest power generator RWE as an investor. It has multiple projects in Australia and the U.S., as well as South Africa, Mexico, and Britain.

Alstom (AOMFF.PK) has also announced development in the promising but challenging field of capturing energy from waves and tides adding to the further interest from major renewable power developers in this emerging industry.

The U.S. Department of Energy has announced several wave energy developments including a cost-shared value of over $18 million, under the DOE’s competitive solicitation for Advanced Water Power Projects. The projects will advance commercial viability, cost-competitiveness, and market acceptance of new technologies that can harness renewable energy from oceans and rivers. The DOE has selected the following organizations and projects for grant awards:

First Topic Area: Technology Development (Up to $600,000 for up to two years)

Electric Power Research Institute, Inc (EPRI) (Palo Alto, Calif.) Fish-friendly hydropower turbine development & deployment. EPRI will address the additional developmental engineering required to prepare a more efficient and environmentally friendly hydropower turbine for the commercial market and allow it to compete with traditional designs.

Verdant Power Inc. (New York, N.Y.) Improved structure and fabrication of large, high-power kinetic hydropower systems rotors. Verdant will design, analyze, develop for manufacture, fabricate and thoroughly test an improved turbine blade design structure to allow for larger, higher-power and more cost-effective tidal power turbines.

Public Utility District #1 of Snohomish County (SnoPUD) (Everett, Wash.) Puget Sound Tidal Energy In-Water Testing and Development Project. SnoPUD will conduct in-water testing and demonstration of tidal flow technology as a first step toward potential construction of a commercial-scale power plant. The specific goal of this proposal is to complete engineering design and obtain construction approvals for a Puget Sound tidal pilot demonstration plant in the Admiralty Inlet region of the Sound.

Pacific Gas and Electric Company – San Francisco, Calif. WaveConnect Wave Energy In-Water Testing and Development Project. PG&E will complete engineering design, conduct baseline environmental studies, and submit all license construction and operation applications required for a wave energy demonstration plant for the Humboldt WaveConnect site in Northern California.

Concepts ETI, Inc (White River Junction, Vt.) Development and Demonstration of an Ocean Wave Converter (OWC) Power System. Concepts ETI will prepare detailed design, manufacturing and installation drawings of an OWC. They will then manufacture and install the system in Maui, Hawaii.

Lockheed Martin Corporation (LMT) – Manassas, Va., Advanced Composite Ocean Thermal Energy Conversion – “OTEC”, cold water pipe project. Lockheed Martin will validate manufacturing techniques for coldwater pipes critical to OTEC in order to help create a more cost-effective OTEC system.

Second Topic Area, Market Acceleration (Award size: up to $500,000)

Electric Power Research Institute (Palo Alto, Calif.) Wave Energy Resource Assessment and GIS Database for the U.S. EPRI will determine the naturally available resource base and the maximum practicable extractable wave energy resource in the U.S., as well as the annual electrical energy which could be produced by typical wave energy conversion devices from that resource.

Georgia Tech Research Corporation (Atlanta, Ga.) Assessment of Energy Production Potential from Tidal Streams in the U.S. Georgia Tech will utilize an advanced ocean circulation numerical model to predict tidal currents and compute both available and effective power densities for distribution to potential project developers and the general public.

Re Vision Consulting, LLC (Sacramento, Calif.) Best Siting Practices for Marine and Hydrokinetic Technologies With Respect to Environmental and Navigational Impacts. Re Vision will establish baseline, technology-based scenarios to identify potential concerns in the siting of marine and hydrokinetic energy devices, and to provide information and data to industry and regulators.

Pacific Energy Ventures, LLC (Portland, Ore.) Siting Protocol for Marine and Hydrokinetic Energy Projects. Pacific Energy Ventures will bring together a multi-disciplinary team in an iterative and collaborative process to develop, review, and recommend how emerging hydrokinetic technologies can be sited to minimize environmental impacts.

PCCI, Inc. (Alexandria, Va.) Marine and Hydrokinetic Renewable Energy Technologies: Identification of Potential Navigational Impacts and Mitigation Measures. PCCI will provide improved guidance to help developers understand how marine and hydrokinetic devices can be sited to minimize navigational impact and to expedite the U.S. Coast Guard review process.

Science Applications International Corporation (SAI) – San Diego, Calif., International Standards Development for Marine and Hydrokinetic Renewable Energy. SAIC will assist in the development of relevant marine and hydrokinetic energy industry standards, provide consistency and predictability to their development, and increase U.S. industry’s collaboration and representation in the development process.

Third Topic Area, National Marine Energy Centers (Award size: up to $1.25 million for up to five years)

Oregon State University, and University of Washington – Northwest National Marine Renewable Energy Center. OSU and UW will partner to develop the Northwest National Marine Renewable Energy Center with a full range of capabilities to support wave and tidal energy development for the U.S. Center activities are structured to: facilitate device commercialization, inform regulatory and policy decisions, and close key gaps in understanding.

University of Hawaii (Honolulu, Hawaii) National Renewable Marine Energy Center in Hawaii will facilitate the development and implementation of commercial wave energy systems and to assist the private sector in moving ocean thermal energy conversion systems beyond proof-of-concept to pre-commercialization, long-term testing.

Types of Hydro Turbines

There are two main types of hydro turbines: impulse and reaction. The type of hydropower turbine selected for a project is based on the height of standing water— the flow, or volume of water, at the site. Other deciding factors include how deep the turbine must be set, efficiency, and cost.

Impulse Turbines

The impulse turbine generally uses the velocity of the water to move the runner and discharges to atmospheric pressure. The water stream hits each bucket on the runner. There is no suction on the down side of the turbine, and the water flows out the bottom of the turbine housing after hitting the runner. An impulse turbine, for example Pelton or Cross-Flow is generally suitable for high head, low flow applications.

Reaction Turbines

A reaction turbine develops power from the combined action of pressure and moving water. The runner is placed directly in the water stream flowing over the blades rather than striking each individually. Reaction turbines include the Propeller, Bulb, Straflo, Tube, Kaplan, Francis or Kenetic are generally used for sites with lower head and higher flows than compared with the impulse turbines.

Types of Hydropower Plants

There are three types of hydropower facilities: impoundment, diversion, and pumped storage. Some hydropower plants use dams and some do not.

Many dams were built for other purposes and hydropower was added later. In the United States, there are about 80,000 dams of which only 2,400 produce power. The other dams are for recreation, stock/farm ponds, flood control, water supply, and irrigation. Hydropower plants range in size from small systems for a home or village to large projects producing electricity for utilities.


The most common type of hydroelectric power plant (above image) is an impoundment facility. An impoundment facility, typically a large hydropower system, uses a dam to store river water in a reservoir. Water released from the reservoir flows through a turbine, spinning it, which in turn activates a generator to produce electricity. The water may be released either to meet changing electricity needs or to maintain a constant reservoir level.

The Future of Ocean and Wave Energy

Wave energy devices extract energy directly from surface waves or from pressure fluctuations below the surface. Renewable energy analysts believe there is enough energy in the ocean waves to provide up to 2 terawatts of electricity. (A terawatt is equal to a trillion watts.)

Wave energy rich areas of the world include the western coasts of Scotland, northern Canada, southern Africa, Japan, Australia, and the northeastern and northwestern coasts of the United States. In the Pacific Northwest alone, it’s feasible that wave energy could produce 40–70 kilowatts (kW) per meter (3.3 feet) of western coastline. The West Coast of the United States is more than a 1,000 miles long.
In general, careful site selection is the key to keeping the environmental impacts of wave energy systems to a minimum. Wave energy system planners can choose sites that preserve scenic shorefronts. They also can avoid areas where wave energy systems can significantly alter flow patterns of sediment on the ocean floor.

Economically, wave energy systems are just beginning to compete with traditional power sources. However, the costs to produce wave energy are quickly coming down. Some European experts predict that wave power devices will soon find lucrative niche markets. Once built, they have low operation and maintenance costs because the fuel they use — seawater — is FREE.

The current cost of wave energy vs. traditional electric power sources?

It has been estimated that improving technology and economies of scale will allow wave generators to produce electricity at a cost comparable to wind-driven turbines, which produce energy at about 4.5 cents kWh.

For now, the best wave generator technology in place in the United Kingdom is producing energy at an average projected/assessed cost of 6.7 cents kWh.

In comparison, electricity generated by large scale coal burning power plants costs about 2.6 cents per kilowatt-hour. Combined-cycle natural gas turbine technology, the primary source of new electric power capacity is about 3 cents per kilowatt hour or higher. It is not unusual to average costs of 5 cents per kilowatt-hour and up for municipal utilities districts.

Currently, the United States, Brazil, Europe, Scotland, Germany, Portugal, Canada and France all lead the developing wave energy industry that will return 30% growth or more for the next five years.


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PaceToday.com, March 16, 2009

abbAUSTRALIA:  ABB has helped Oceanlinx to construct a 250kW Wave Energy Conversion unit – a full-scale prototype designed to extract energy from ocean waves and convert it to electricity or to convert ocean water to clean water. 

The Wave Energy Conversion unit was completed at the ABB Performance Service Centre located in Port Kembla, NSW, Australia. The unit can save thousands of tonnes of CO2 and SO2 emissions annually, says ABB. 

It is a full-scale prototype with a unique commercially-efficient system for extracting energy from ocean waves and converting it to electricity, or utilising that energy to produce clean, fresh water from brine. 

ABB was involved in fabrication modifications and installation of the Wave Energy Conversion unit hood and steel work – including stiffening sections of the structure and fabricating two watertight doors. 

Oceanlinx Limited is an international company working in wave energy conversion. It developed the proprietary technology for extracting energy from ocean waves and converting it into electricity, or utilising that energy to provide desalinated industrial or potable grade water from sea water. 

Oceanlinx has a power purchase agreement with Australian utility Integral Energy for the supply of electricity from the 250kW prototype unit. 

All work was finished on schedule in early February, enabling the unit to be floated out to its operational location off the breakwater north of Port Kembla harbour, NSW, Australia.

“ABB were professional, safety conscious and flexible in meeting all our requirements and we have been delighted with the fabrication, modifications and installation work performed,” said Oceanlinx chief operating officer, Stuart Weylandsmith. 

Oceanlinx’s core patented technology is an oscillating water column (OWC) device, based on the established science of wave energy, but one which, when compared to other OWC technologies offers major improvements in the design of the system, the turbine, and in construction technique, according to ABB. 

The technology has been successfully constructed and tested with the first full scale Oceanlinx wave plant, installed at Port Kembla producing zero CO2 and SO2 pollution.

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Science Daily, December 20, 2008

0812161141021MIT researchers are working with Portuguese colleagues to design a pilot-scale device that will capture significantly more of the energy in ocean waves than existing systems, and use it to power an electricity-generating turbine.

Wave energy is a large, widespread renewable resource that is environmentally benign and readily scalable. In some locations — the northwestern coasts of the United States, the western coast of Scotland, and the southern tips of South America, Africa and Australia, for example — a wave absorbing device could theoretically generate 100 to 200 megawatts of electricity per kilometer of coastline. But designing a wave capture system that can deal with the harsh, corrosive seawater environment, handle hourly, daily and seasonal variations in wave intensity, and continue to operate safely in stormy weather is difficult. 

Chiang Mei, the Ford Professor of Engineering in the Department of Civil and Environmental Engineering, has been a believer in wave energy since the late 1970s. After the recent oil price spike, there has been renewed interest in harnessing the energy in ocean waves.

To help engineers design such devices, Professor Mei and his colleagues developed numerical simulations that can predict wave forces on a given device and the motion of the device that will result. The simulations guide design decisions that will maximize energy capture and provide data to experts looking for efficient ways to convert the captured mechanical energy to electrical energy.

One country with a good deal of expertise in wave energy research and development is Portugal. For the past three years, Mei has been working with Professors Antonio Falcao, Antonio Sarmento, and Luis Gato of Insitituto Superior Tecnico, Technical University of Lisbon, as they plan a pilot-scale version of a facility called an oscillating water column, or OWC. Situated on or near the shore, an OWC consists of a chamber with a subsurface opening. As waves come in and out, the water level inside the chamber goes up and down. The moving surface of the water forces air trapped above it to flow into and out of an opening that leads to an electricity-generating turbine. The turbine is a design by A.A.Wells in which the blades always rotate in the same direction, despite the changing direction of the air stream as the waves come in and out.

The Portuguese plan is to integrate the OWC plant into the head of a new breakwater at the mouth of the Douro River in Porto, a large city in northern Portugal. Ultimately, the installation will include three OWCs that together will generate 750 kilowatts — roughly enough to power 750 homes. As a bonus, the plant’s absorption of wave energy at the breakwater head will calm the waters in the area and reduce local erosion.

The challenge is to design a device that resonates and thus operates efficiently at a broad spectrum of wave frequencies — and an unexpected finding from the MIT analysis provides a means of achieving that effect. The key is the compressibility of the air inside the OWC chamber. That compressibility cannot be changed, but its impact on the elevation of the water can be — simply by changing the size of the OWC chamber. The simulations showed that using a large chamber causes resonance to occur at a wider range of wavelengths, so more of the energy in a given wave can be captured. “We found that we could optimize the efficiency of the OWC by making use of the compressibility of air — something that is not intuitively obvious,” Mei says. “It’s very exciting.”

He is currently working with other graduate students on wave power absorbers on coastlines of different geometries and on how to extract wave power from an array of many absorbers.

Mei continues to be enthusiastic about wave energy, but he is not unrealistic in his expectations. Although costs have been falling in recent years, wave energy is unlikely to be commercially viable for a long time — perhaps several decades. Nevertheless, Mei is adamant that more attention should be given to this renewable source of energy, and he would like to see a team of MIT experts in different fields — from energy capture and conversion to transmission and distribution — working collaboratively toward making large-scale wave energy a reality.

“Given the future of conventional energy sources, we need lots of research on all kinds of alternative energy,” he says. “Right now, wind energy and solar energy are in the spotlight because they’ve been developed for a longer time. With wave energy, the potential is large, but the engineering science is relatively young. We need to do more research.”

This article is adapted from a longer version that appeared in the autumn 2008 issue of Energy Futures, the newsletter of the MIT Energy Initiative.

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La Société, April 24, 2008

RWE Innogy has submitted a planning application to the relevant authorities for one of the world’s first wave power stations off the Scottish coast. The pilot plant with an output of four megawatts will be installed in Siadar Bay on the Isle of Lewis. If everything goes to plan, construction work could begin in 2009.

“We have taken an important step forward in our plans to build one of the world’s first commercial-scale wave power stations. We are convinced that this technology has a great potential to generate power around Europe’s coast”, explains Kevin McCullough, COO of RWE Innogy. The project is being coordinated by the British RWE Innogy subsidiary npower renewables, who are promoting the development of the wave power station together with the Scottish technology company Wavegen.

Unlike a tidal power station, this does not exploit the difference in height between ebb tide and flood tide but rather the constant kinetic energy of waves. The plan is to build a breakwater system according to the OWC (oscillating water column) principle on the open sea. The breaking waves force water into an opening below water level, which is then sucked out again when the waves retreat. This constant rise and fall sets a column of water trapped in several chambers in motion. The air mass above water is thus alternately compressed and sucked in, powering a turbine that generates electricity. The pilot plant’s output will be enough to supply around 1,500 homes with electricity.

RWE Innogy had already announced a cooperation with the British firm of Marine Current Turbines to plan and build one of the world’s first tidal stream power stations off the coast of Anglesey in North Wales in February. This project will use the natural ocean and tidal currents to generate power through underwater rotors. The system will have an output of around 10.5 megawatts and is scheduled to go into operation in 2012.

RWE Innogy, the company for renewable energies in the RWE Group, is planning to invest an average of one billion euros each year to extend its regenerative power generation business. The main focus will be on wind, water and biomass projects throughout Europe. RWE Innogy will expand its installed power station output based on renewable energies to 4,500 megawatts by the year 2012.

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IMC Brokers, October 23, 2007

Generating Renewable Energy from Ocean Waves

Wave power refers to the energy of ocean surface waves and the capture of that energy to do useful work – including electricity generation, desalination, and the pumping of water (into reservoirs). Wave power is a form of renewable energy. Though often co-mingled, wave power is distinct from the diurnal flux of tidal power and the steady gyre of ocean currents. Wave power generation is not a widely employed technology, and no commercial wave farm has yet been established (although development for the first commercial wind farm in the Orkneys are well under way).

Below you will find a selection of technologies used to convert wave energy into electricity.

Pelamis Wave Energy Converter: The Pelamis is a semi-submerged, articulated structure composed of cylindrical sections linked by hinged joints. The wave-induced motion of these joints is resisted by hydraulic rams, which pump high-pressure oil through hydraulic motors via smoothing accumulators. The hydraulic motors drive electrical generators to produce electricity. Power from all the joints is fed down a single umbilical cable to a junction on the sea bed. Several devices can be connected together and linked to shore through a single seabed cable.

Finavera’s AquabuOY: The AquaBuOY is a floating buoy structure that converts the kinetic energy of the vertical motion of oncoming waves into clean electricity. It utilizes a cylindrical buoy as the displacer and the reactor is a large water mass enclosed by a long vertical tube underneath the buoy.

Aegir Dynamo: The Aegir Dynamo™ functions in a unique fashion by generating electrical current from the motion of the prime mover in one phase via a direct mechanical conversion and the use of a bespoke buoyancy vessel.

[YouTube=http://www.youtube.com/watch?v=r7-EPR8Ss6M”]Wave Dragon: Wave Dragon is a floating, slack-moored energy converter of the overtopping type that can be deployed in a single unit or in arrays of Wave Dragon units in groups resulting in a power plant with a capacity comparable to traditional fossil based power plants.

[YouTube=http://www.youtube.com/watch?v=cGD20eObcF8″]OWC Pico Power Plant: Wave enters in the “hydro-pneumatic chamber” (resembling a cave with entry below the waterline). Up-and down- movement of water column inside chamber makes air flow to and from the atmosphere, driving an air turbine. The turbine is symmetric and is driven indifferently in which direction the air flows.

AWS Wave Energy Converter
AWS Wave Energy Converter: The AWS (Archimedes Wave Swing) wave energy converter is a cylinder shaped buoy, moored to the seabed. Passing waves move an air-filled upper casing against a lower fixed cylinder, with up and down movement converted into electricity.
As a wave crest approaches, the water pressure on the top of the cylinder increases and the upper part or ‘floater’ compresses the gas within the cylinder to balance the pressures. The reverse happens as the wave trough passes and the cylinder expands. The relative movement between the floater and the lower part or silo is converted to electricity by means of a hydraulic system and motor-generator set.

Open-Centre Tidal Turbine
OpenHydro: The company’s vision is to deploy farms of open-centre tidal turbines under the world’s oceans – silently and invisibly generating electricity at no cost to the environment. OpenHydro’s technology enables the ocean’s immense energy to be harnessed for the benefit of all. The Open-Centre Turbine, with just one moving part and no seals, is a self-contained rotor with a solid state permanent magnet generator encapsulated within the outer rim, minimising maintenance requirements.

SPERBOY: Developed and patented by Embley Energy, is a floating wave energy converter based on the ‘oscillating water column’ principle. Air displaced by the oscillating water column is passed through turbine-generators. Designed to be deployed in large arrays 8 to 12 miles off shore SPERBOYTM provides large-scale energy generation at a competitive cost.

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CHRIS MORRISON, VentureBeat.com, March 4, 2008

Vast amounts of power are locked away in the movements of the ocean, but because of technical challenges, the number of startups that have attempted to harness wave power thus far is relatively small when compared to wind or solar.

OreCon is the latest, with plans for a sort of giant, self-contained buoy that floats atop the water, each unit generating a megawatt and a half of energy. The company has raised $24 million, which it plans to use in building a full-scale example.

One of the problems with putting mechanical equipment in the ocean is that the salt and other chemicals in sea water tend to destroy moving parts. OreCon uses a design called the Oscillating Water Column to keep most of the parts well above water level.


In an OWC, which is a well-known setup, the pressure from waves outside the device causes water to rise and fall within it, which in turn pushes air in and out through a turbine, creating energy. They tend to be fairly inefficient, though.

OreCon’s innovation is using what it calls “multi-resonant chambers”. In its proprietary design, the company deploys multiple OWCs around a 40 meter platform that’s tethered to the sea floor a few miles off shore.

The first unit should be deployed somewhere off the coast of England in Cornwall, near Plymouth, where OreCon was founded six years ago. Closer to home, rival designs by Finavera Renewables and Pelamis Wave Power are planned for deployment off the coast near San Francisco.

The funding OreCon raised was for £12 million (about $24 million US dollars). The round was led by Advent Venture Partners, and Venrock, Wellington Partners and Northzone Ventures also participated.

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