The Energy Blog

Largest Tidal Stream System Installed

Marine Current Turbines, has successfully completed the first installation phase of the 1.2MW SeaGen Tidal System, previous post, the world’s largest grid-connected tidal stream system, into the fast-flowing waters of Strangford Narrows off the coast of Northern Ireland.

A crane barge safely positioned the 1000 ton structure onto the seabed in the early hours of Wednesday morning, 2 April, and released its four moorings on 3 April. SeaGen’s location is roughly 1km south of the ferry route between Strangford and Portaferry, approximately 400m from the shoreline.

When fully operational later in the summer, its 16m diameter, twin rotors, one shown above, will operate for up to 18-20 hours per day to produce enough clean, green electricity, equivalent to that used by a 1000 homes, four times greater than any other tidal stream project so far built.

“SeaGen is a hugely exciting project, as well as an historic achievement for both Marine Current Turbines and for renewables in the UK and Ireland. Tidal energy has the great advantage of being predictable and no other system can harness the power of the tidal currents in the way this one can. We take great pride and see enormous potential in the technology and hope it will eventually make a significant contribution to the future energy needs of the British Isles, Ireland and beyond.”

-- Martin Wright, Managing Director of Marine Current Turbines

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Plans Announced for a Wave Power Plant in Hawaii

Oceanlinx, an Australian wave energy company, announced plans for a $20 million project to install three floating wave energy converters (WECs), i.e. wave-powered turbine platforms, to supply up to 2.7MW of electricity to the island of Maui, Hawaii. The company has signed a Memorandum of Understanding with Renewable Hawaii, Inc. (RHI), for potential passive investment in a project . RHI is owned by the Hawaiian Electric Company, Inc.

The project could be operational by the end of 2009.

Oceanlinx’s unit combines the established science of the Oscillating Water Column (OWC) with its own patented turbine technology, and has successfully completed a full scale trial at its pilot unit at Port Kembla, Australia.

Each WEC is about 65 by 100 feet and 15-25 feet high and will not likely affect views from land.

Seadog Wave Pump Exceeds Epectations

Independent Natural Resources Inc's. ( INRI^TM) SEADOG^TM wave pump is a form of wave power that has been around for a while that I hadn't heard of. It seems to me to have several advantages over other forms of wave power, being simpler than most, consuming no external power and having no electrical cables connecting it to the shore.

The SEADOG^TM pump captures ocean-wave energy to pump large volumes of seawater, consuming no fuel or electricity. The pump uses buoyancy to convert wave energy to mechanical energy. The main components of the  pump include a buoyancy chamber (the lower cage in the picture, buoyancy block (yellow object), piston assembly (center of upper chamber), piston shaft, piston cylinder, and intake and exhaust valves.  When positioned in the water the buoyancy block (filled with air) floats within the buoyancy chamber, moving up and down in relation to the ocean waves and swells. The buoyancy block is connected to the piston shaft which in-turn moves the piston assembly through the piston cylinder.

As the buoyancy block moves down in the trough of a wave it draws the piston downward through the piston cylinder.  The downward movement draws water into the piston cylinder through the intake valve filling the piston cylinder chamber. As the next wave lifts the buoyancy block the water within the piston cylinder is under pressure and is expelled through the exhaust valve (into the air in the picture). Each cycle of the buoyancy block rising and falling, drawing in and expelling water, is called a stroke. Each stroke of the piston causes the water to be pumped from the piston cylinder in a regular manner.

FYI: Washington Wave Power Project Gets FERC Approval

The first approved wave-power program in the United States has been given a green light for a pilot project in Makah Bay, a remote section of the Pacific Ocean just off of the northwestern tip of the Olympic Peninsula.

Finavera's (TSX: FVR.V ) (previous post) Makah Bay pilot plant will begin with four 250-kilowatt buoys anchored in an array 1.9 miles offshore. Electricity will be transmitted onshore using nearly four miles of underwater cable that eventually connects to a station on land that feeds into the Clallam County Public Utility District's power transmission grid.  . . . more

According to the Seattle Post Intelligence, the Electric Power Research Institute estimates that waves off the Washington, Oregon and California coasts could produce from 250 to 500 terawatt-hours per year. A terawatt-hour is a million megawatt-hours, or a billion kilowatt-hours. The nation uses about 4,000 terawatt-hours of electricity every year.  . . . more

In separate news item PG&E and Finavera Renewables announced the nation’s first commercial wave energy power purchase agreement for two megawatt (MW) of commercial wave energy. Located off the Northern California coast, the Humboldt County Offshore Wave Energy Power Plant will be developed by Finavera Renewables. The project is expected to begin delivering renewable, clean electricity in 2012.

AquaBuOY 2.0 Deployed Off Oregon Coast

Finavera Renewables Inc. (TSX-V: FVR.V) announced that it has successfully completed a major milestone in its wave energy development program with the deployment and commissioning of the AquaBuOY 2.0 wave energy converter off the coast of Newport, Oregon. This marks the first installation of a wave energy converter of this scale off the west coast of North America and moves the Company closer to achieving its goal of commercial electricity generation from ocean waves by 2010.

The AquaBuOY is a floating buoy structure that converts the kinetic energy of the vertical motion of oncoming waves into clean electricity.

The AquaBuOY 2.0 is situated approximately two and a half miles off the coast of Newport, Oregon. Over the next several weeks, Finavera Renewables will test and analyze the performance of the half-size prototype's components and monitor its hydraulic power output. During this phase, all onboard diagnostic equipment will be powered by an onboard Pelton turbine as well as solar panels and small wind turbines installed on the device. Data is being streamed live via wireless and satellite technology for analysis. This test data will be used for the design of a larger version, for commercial deployment, with a capacity of 250 kW, scheduled for construction in 2008. The current project does not generate power, rather the company wants to study the pressure output of the device.

Artifical Muscle Produces Ocean Power

SRI International has announced the deployment of a prototype buoy-mounted, ocean wave-powered generator off the coast of Florida in the Tampa Bay. The electroactive polymer artificial muscle (EPAM™) technology is used to produce electricity as they bob up and down attached to buoys. The deployment is part of a program sponsored by HYPER DRIVE Corporation, Ltd., a Japanese company focused on development and deployment of wave-powered generators around the world.

The wave-powered generators can be deployed on existing ocean buoys that use batteries as their energy source. The new generator utilizes patented electroactive polymer artificial muscle (EPAM™) technology, and offers a renewable method to continually power ocean buoys. The bouys will be equipped with instrumentation that allows remote monitoring of the generator’s output energy as well as wave height and buoy motion.  SRI is working with Artificial Muscle, Inc., an SRI spin-off company and the exclusive licensee of EPAM, in the development of the EPAM components for the wave-powered generators.

The generator, initially deployed on a navigation buoy for ports and harbors, is capable of generating 20 joules of energy per stroke, which corresponds to an average output power of more than 5 watts under typical ocean wave conditions. The current development program aims at developing generators that can produce 25 watts of average output power. This is sufficient to supply all the power required by navigational buoys. Future efforts will address the design, development, and deployment of wave-powered generators capable of generating power in the kilowatts range for large-scale clean energy production.

1.2 MW Tidal Energy Turbine Ready for Installation

According to a June 6, 2007 press release by Marine Current Turbines Ltd (MCT), the installation of its 1.2 MW SeaGen commercial tidal energy system will commence during the week of August 20th in Northern Ireland’s Strangford Lough. SeaGen will be the world’s largest tidal current device and will generate clean and sustainable electricity for approximately 1000 homes. Being a full size prototype, no scale up will be required for future commercial installations.

SeaGen consists of twin axial flow rotors, each of 16m diameter driving a generator via a gearbox much like a hydro-electric turbine or a wind turbine. The twin power units of each system are mounted on wing-like extensions either side of a tubular steel monopile 3m in diameter which is set into a hole drilled into the seabed. SeaGen will generate electricity from the flow in both directions.

On June 21 MCT annnounced that it had secured £7.5 million ($15 million) in funding from investment and savings bank Triodos Bank, along with new money from hedge fund AM2 (Bermuda) Ltd and some existing shareholders, will support the SeaGen tidal energy project and facilitate the company’s corporate ambitions and future project developments in UK and international waters.

Ocean Power Plugged in USA Today

USA Today had an article in yesterdays edition giving a big plug for ocean power, with descriptions of the major technologies.

Developers are using an array of contraptions — from spinning turbines to bobbing buoys and undulating, snakelike cylinders — to convert ocean or river movements into electricity.

The world's first commercial wave farm is scheduled to launch this summer off Portugal's coast. The first pilot tidal generator in the USA revved up in New York City's East River last December. And the USA's first utility-scale wave project, off Oregon beaches, won preliminary federal approval this year. All told, the Federal Energy Regulatory Commission has cleared 21 preliminary permits, and about 35 are pending for wave and tidal projects ...

Marine energy has some distinct advantages over its chief rival, wind power. ... more in USA Today

PG&E to Test Wave Power Technologies

PG&E To Study Wave Power In Humboldt & Mendocino
PG&E Press release, February 28, 2007

Pacific Gas and Electric Company took the first step towards developing generation projects that could convert the abundant wave energy off the coast of Mendocino and Humboldt Counties of California into electricity. Named "WaveConnect," the proposed developments would extend PG&E's environmental leadership by providing its customers with a new source of clean, renewable power. ...

The WaveConnect projects will begin with resource, environmental, and ocean use studies and if developed would use wave energy conversion (WEC) devices to transform the energy of ocean waves into clean, renewable electricity. This would be the first application in North America for a project that would allow multiple WEC device manufacturers to demonstrate their devices on a common site, which could help accelerate the development of wave energy technology. ...

PG&E, as the lead developer, will be responsible for the permitting of the sites and will encourage the participation of multiple WEC device manufacturers in the projects. ... Phased development of the sites would proceed if technical results support feasibility, environmental studies show that any significant impacts can be fully mitigated, and stakeholder considerations can be satisfactorily addressed.

PG&E intends to utilize the most effective technologies for the wave energy projects. If fully developed, the projects could each provide up to 40 megawatts of clean renewable electric supply.

Scottish Wave Farm Receives Funding

A Scottish company, AWS Ocean Energy Ltd., that had slipped under my radar, has secured £2.128 million (US$4.16 million) in funding from the Scottish Executive. The funds will be used to develop and commercialize AWS’ Archimedes Wave Swing, claimed to be one of the few proven technologies worldwide for generating clean, renewable electricity from the ocean’s waves.

The Archimedes Wave Swing, shown left (artist apparently took some liberty by showing it above the water surface), is submerged at least six meters below the sea surface which, as well as removing visual impact and hazards to shipping, avoids high storm impacts. Compared to most other wave energy devices, the Wave Swing also takes up a proportionately smaller area of the sea, in relation to power generated. Following a successful pilot project in Portugal, the £2.128 million will be used to develop a pre-commercial model of the device at the European Marine Energy Centre (EMEC) in Eday, Orkney.