More companies planning to site R&D and manufacturing centres for offshore wind in UK

A series of very interesting news after the Crown Estate’s Round 3 Offshore Programme announcement are showing how the major wind power international players are keen to be part of the expected substantial growth in UK offshore wind:

Clipper Windpower to open a wind turbine blade manufacturing facility in Blyth working in collaboration with NaREC

Mitsubishi Power Systems Europe (MPSE) opening a research and development centre for offshore wind turbines

Both Siemens and General Electric announcing plans for offshore wind turbines production bases in UK

These are all serious players in the wind energy sector, so extremely good news for offshore wind and the UK.

Investments are however explicitly linked to the Offshore Wind Site Development Competition, the plan announced in the last budget, to distribute £60m in funding to support the upgrade of one (or more) port facilities and production sites specifically designed to support offshore wind development.

Siemens says that “is currently appraising the suitability of potential sites for the production plant, both on the east coast and in the northeast of the UK, with a special focus on the harbour infrastructure” and GE press release includes “(t)his investment will follow the successful outcome of the UK government’s infrastructure competition, aimed at supporting the development of renewable energy in the United Kingdom”.

Now, the details of the competition have not been published yet and it is reasonable to assume that whole selection process will not be completed before Autumn at best. But what about the elections? Are we sure that all this will go on regardless of who will be in government?

Well, I will try to be optimist and assume that all these companies have already done their homework and verified that the plan is supported by all major political parties. I hope. We should be keeping an eye on this.

References:

Clipper Windpower press release

NaREC

The Independent

Siemens press release

GE press release

DECC

EWEA: “European offshore wind power market grew 54% in 2009″

From the European Wind Energy Association site:

“In 2009, a total of eight new wind farms consisting of 199 offshore wind turbines, with a combined power generating capacity of 577 MW, were connected to the grid in Europe. This represents a growth rate of 54% compared to the 373 MW installed during 2008. For 2010, the European Wind Energy Association (EWEA) expects the completion of 10 additional European offshore wind farms, adding 1,000 MW and equivalent to market growth of 75% compared to 2009.”

Detail of 2009 new offshore wind installations

“[...] Currently, 17 offshore wind farms are under construction in Europe, totaling more than 3,500 MW, with just under half being constructed in UK waters. In addition, a further 52 offshore wind farms have won full consent in European waters, totaling more than 16,000 MW, with just over half of this capacity planned in Germany.

In 2009, the turnover of the offshore wind industry was approximately €1.5 billion, and EWEA expects this to double in 2010 to approximately €3 billion. 

[...] 

More than 100 GW of projects are at various stages of planning and could provide enough power to meet 10% of European electricity demand. 

Europe is the world leader in offshore wind with 828 wind turbines and a cumulative capacity of 2,056 MW spread across 38 offshore wind farms in nine European countries. The UK and Denmark are the current leaders, with a 44% and 30% share respectively. In 2009, five countries built new offshore wind farms: UK (284 MW), Demark (230 MW), Sweden (30 MW), Germany (30 MW), Norway (2.3 MW).[...]

Reference : EWEA

Offshore Wind 2009 status note | in RenewableEnergyWorld.com

Very interesting status on Offshore Wind projects read in RenewableEnergyWorld.com on 09 December 2009 (by E.de Vries)

 

<< Europe is currently the global sector leader and during 2008, 366 MW of new offshore wind capacity was installed, taking the cumulative total to 1471 MW – all built in European waters. Multiple sources quote different expectations for new installation figures for Europe, ranging 430–760 MW in 2009, 1100–1180 MW in 2010, and another 1120–1500 MW in 2011.

Furthermore, EWEA’s scenario report states, cumulative offshore wind capacity in Europe may reach 40 GW by 2020 and 150 GW in 2030. However, despite the importance of a rapid increase in offshore capacity, much more relevant than adding megawatts is a shift in focus towards optimising power generation potential per installed MW for the lowest lifecycle costs. Several examples of leading wind turbine suppliers that have developed dedicated solutions for specific (environmental) circumstances emerged at the European Offshore Wind event.

Among many milestones that have taken place in the wind industry during 2009 was the installation of China’s first 3-MW (rotor diameter 90 metres) Sinovel offshore wind turbine. This first unit of the 100-MW Shanghai Donghai Bridge demonstration project undoubtedly marks the first of many future offshore wind farms to be built along Chinese shores.

Among several future Chinese wind industry players is former Dutch entrant DarWinD, which had just commenced building a 5-MW direct-drive prototype turbine before its June 2009 bankruptcy. Chinese firm Xiangtan Electric Manufacturing Group (XEMC) acquired DarWinD hardware and Intellectual Property (IP). Amongst other things XEMC manufactures generators, control equipment, large castings and forgings. The company already manufactures a 2-MW wind turbine in cooperation with Harokasan of Japan that has owned the direct drive technology from former Dutch group Zephyros since 2005.

DarWinD’s turbine concept also builds on Zephyros wind technology. Company sources say that the renamed XEMC DarWinD plans to erect a land prototype in the Netherlands and an offshore prototype in China.

US Offshore Wind

Recent reports from the USA refer to about 37 offshore wind projects that are ‘in the works’. A further prediction is that within the next five years the first U.S. offshore wind project will come on line.

Through its ScanWind purchase in September (see REW September–October 2009), GE can potentially become a major player in the emerging US offshore market, even though the initial focus is on the European sector, according to comments made by GE’s vice president of renewables, Victor Abate.

With regard to further ScanWind technology development, Abate explicitly referred to his company’s workhorse strategy, which is based upon producing large quantities of a limited range of products: ‘When we acquired Enron Wind in 2002, about 1000 1.5-MW turbines were operational. Today total numbers in operation worldwide exceed the 12,000 mark. The Arklow Bank offshore project served as a learning platform for us and we are excited about ScanWind direct drive technology in terms of proven reliability. At the moment availability of their turbines is already 96%–97%, achieved by operation under harsh Norwegian coastal conditions.’

According to the company, next year GE’s offshore turbine will be offered to the market, with first deliveries planned for 2012–2013. However, Abate did not make any specific mention of major product parameters such as the product power rating and rotor size.

Perhaps unsurprisingly, the long-delayed German offshore wind market kick-off – and many projects being in deep water locations far from shore – coincides with a steadily expanding market entry role for ‘super class’ 5–6 MW installations. The fact that Areva Multibrid and REpower will each erect six of their 5-MW turbine models in German waters this year can be regarded as another genuine milestone in offshore wind development.

This year a third German supplier, BARD Engineering, plans to begin installation of 80 Tripile foundations for its 400-MW BARD Offshore I North Sea project, in many respects a huge challenge. The Areva Multibrid and REpower 5-MW prototypes were erected in 2004, while the BARD prototype installation followed three years later.

Second Generation

REpower took 2–2.5 years to complete its second-generation 6.15-MW 6M, an up-scaling development of the 5M offshore turbine, now a serial product, with its initial capacity of 5 MW. The 126-metre rotor diameter remained unchanged and earlier this year the company erected three 6M onshore prototypes. Novelties associated with the design include a new 6.6 kV water-cooled generator (previously 950 kV) and a newly designed gearbox, with a 20% higher torque rating but a similar component mass when compared with the 5M.

Furthermore, the 6M’s frequency converter system features three modules, which as a redundancy measure enables continued operation at a reduced output of 67% in the event that one module fails. REpower says that the 6M yields 10% more energy compared to the 5M at sites with an average wind speed of 10 m/s (using LM 61.5 metre P blades), and will become available for offshore projects from 2012. In future the 6M will be delivered with in-house developed and manufactured RE 61.5 metre blades.

BARD Engineering focuses on high-wind offshore applications and has announced plans to erect two different prototype versions of its second-generation 6.5-MW BARD 6.5, with an unchanged 122-metre rotor diameter, in 2010. One version comprises a hydrodynamic WinDrive system from Voith that enables variable speed wind turbine operation combined with a directly grid-connected fixed speed generator, eliminating the need for a power converter. A second version will be fitted with a ‘conventional’ mechanical drive system (for more on this development see REW July–August 2009).

The most powerful turbine on the market currently is Enercon’s E-126 machine. This IEC Wind Class 1A direct drive turbine (with a rotor diameter of 127 metres) is now rated at 7.5 MW (previously 6 MW), but is not currently available for the near shore and offshore wind market.

Meanwhile, two novel offshore wind turbine development projects have come from the Netherlands. Emerging player in the sector 2-BEnergy is developing a 6-MW two-bladed turbine concept with a 130-metre rotor diameter and with prototype erection envisaged for early 2011.

The turbine will be fitted with a conventional geared drivetrain system, while downwind or upwind rotor configurations are both being evaluated as potential options, said company spokesperson Herbert Peels this September. A genuine offshore wind industry novelty is that the nacelle is mounted on a so-called ‘full truss’ support structure. This arrangement eliminates the traditional ‘tower plus foundation’ solution as, instead, an integrated single assembly extends from the seabed to the yaw bearing below the nacelle.

Denoted as the Delft Offshore Turbine (DOT), a second Dutch research and development project that commenced in 2008 is pursuing a radical step away from incremental offshore wind turbine development. Aimed at designing ‘the ultimate offshore turbine’, a key goal of the project is to drastically reduce the number of key components compared to ‘conventional’ state-of-the-art wind turbines currently applied offshore.

The DOT concept consists of a two-blade, fixed-pitch 5–10 MW wind turbine arrangement that directly drives a ‘closed loop’ water displacement pump located in the nacelle. High-pressure water flow generated by this pump drives a submerged hydraulic motor coupled to a second pump. That component in turn is part of an ‘open loop’ high-pressure seawater-based circuit. High-pressure seawater flow from individual wind farm turbines is then channelled to a central Offshore High Voltage Station (OHVS) where multiple hydro-generators convert the hydraulic power into electrical power of the required voltage level.

Delft researchers view power conversion into electricity at centralized level as a substantial system simplification and a major advantage compared to the current state-of-the-art solution in which electrical power conversion is executed at wind turbine level. In an approach analogous to ‘conventional’ offshore wind farms electrical power from the OHVS is finally fed to the onshore high-voltage network.

According to an ambitious programme, DOT technology will be ready for commercial applications as a package within the second half of the next decade.

Elsewhere, UK-based wind industry newcomer VertAx Wind Ltd revealed plans to develop a novel 10-MW three-blade vertical-axis offshore wind turbine it expects to enter the home wind market commercially by 2014. Its massive H-shaped stall-type Darrieus rotor is expected to reach 140 metres in diameter, while the blade length is 110 metres. The turbine will further be fitted with twin 5-MW direct driven generators made by Converteam, each located at a different elevation level. A major feature supporting operations and maintenance is a helicopter-landing platform integrated within the tower’s top section.

The company’s overall objective is to substantially reduce the cost of offshore wind power generation by offering installations boasting the fewest number of moving parts currently known in industry. The required total development budget, including a completed prototype, is estimated at about £35 million (€40 million).

In a more advanced product development phase than either DOT or VertAx is the 10-MW Clipper C-150 Britannia offshore turbine development, taking place in Blyth, in the UK. This giant will be fitted with in-house developed 71.5-metre rotor blades resulting in a record 150-metre rotor diameter, and the design is to be certified for a 30-year life.

As with the 2.5-MW Liberty turbine, this new machine also features a geared distributed drive system with four generators. And, according to Clipper Windpower Marine Limited managing director David Still, the total number of drive system components has not increased, despite a much larger total gear ratio (i.e. rotor speed 6.05–11.5 RPM). Still explained, ‘Another major benefit of the drive system choice is that the turbine can continue operations with one or more generators removed until replacement is performed.’

He further clarified confusion that has arisen over the C-150 power rating, saying that the land prototype will generate a maximum of 7.5 MW. The 10-MW offshore version will ‘simply’ spin a lot faster. Also remarkable is that the increase in the turbine’s Top Head Mass (THM) – nacelle + rotor – associated with the increased output (2.5 => 10 MW) will not be cubed but linear. Elaborating on product specifications Still said: ‘The C-150’s THM will be in line with the figure of state-of-the-art conventional 5–6 MW turbines, [Editors's note: state-of-the-art is about 350–460 tonnes] that in turn provides the right preconditions to our overall strategy of achieving a 50% reduction in installed costs per MW, and a further 30% reduction in foundation costs per MW.

With regard to component mass, individual 2.6-MW Britannia generators are, for instance, only about 20% heavier compared to their 0.66-MW Liberty equivalents.’ He added that this favorable figure can partly be attributed to a switch from 1320 V DC to a 3600 V AC, which requires less copper. A second major contributing factor to mass reduction is the fact that, according to Clipper technical specifications, Britannia generators turn about twice as fast when compared with the Liberty machine’s generators, rated at 2270 versus 1133 RPM, respectively. Testing the turbine’s subassemblies commenced in 2009 and will continue through 2010, with full drivetrain and blade testing scheduled in early 2011. Clipper plans to erect the onshore prototype by the end of 2011.

Offshore Workhorse

Siemens Energy released a second-generation 3.6-MW offshore wind turbine featuring a 120-metre rotor diameter. The new model’s power to swept area ratio (P/A) is only 0.32, a value that until recently was usually restricted to onshore turbines operating in low and medium wind speed conditions. Technologically the SWT-3.6-120 is based upon the proven SWT-3.6-107 (prototype erected in 2004) that has developed into the offshore wind industry workhorse over the last few years. For example, the world’s biggest offshore project so far, Greater Gabbard, will comprise 140 of the SWT-3.6-107 turbines when completed, planned for commissioning in May 2011.

‘We anticipate that our SWT-3.6-120 will generate roughly 10% more electricity at a typical offshore site compared to the SWT-3.6-107’, commented Siemens Wind Power CEO Andreas Nauen on the new product’s potential. Siemens has already installed 100 of its 3.6 MW turbines with another 700 units on order and earlier this year Dong Energy signed orders for over 450 SWT-3.6-120 machines.

Since 1995, Vestas Wind Systems of Denmark has installed over 400 offshore wind turbines with a total capacity exceeding 900 MW. In recent years the company has lost market share to Siemens, but aims to recapture it with a new V112-3.0 MW offshore model. According to the company, the new flagship turbine delivers optimal output in average wind speeds up to 9.5 m/s and will be individually IECS class certified for each separate offshore project.

V112-3.0 MW Offshore marketing will commence immediately. Vestas will install two V112-3.0 MW prototypes onshore in January and mostly likely April 2010 followed by serial delivery in 2011, a company spokesperson stated. Unlike the lightweight V90-3.0 MW turbine applied in several offshore wind farms, the new flagship features a conventional non-integrated geared drive system and, in a novelty for Vestas, a permanent magnet-type synchronous generator.

In addition, on 27 October Vestas partially lifted the curtain on a new 6-MW offshore turbine with a 130–140 metre rotor diameter that it is working on. Other technical specifications and envisaged market introduction time scale details have not been made available yet, but according to well-informed wind industry sources it will be a direct drive turbine fitted with a Vestas-designed annular generator.

Finally, Vestas has joined a research programme with Nowitech of Norway on the development of floating foundations suitable for water depths of more than 30 metres.

Downwind Floating Turbine Cooperation

Earlier this year French nuclear engineering giant Areva acquired German rotor blade manufacturer PN Rotor GmbH. The latter company was owned by Prokon Nord Energiesysteme GmbH and supplied all rotor blades for Multibrid M5000 turbines. Prokon is an Areva Multibrid minority shareholder with a 49% stake and also built and operates a foundry for M5000 main castings.

In a separate development, Areva and Norwegian renewable energy company SWAY AS announced a cooperation deal in August aimed at offering new solutions for exploiting offshore wind power in deep water. Areva Multibrid will adapt its 5-MW M5000 wind turbine, which was specifically designed for offshore applications, to enable downwind operation on SWAY’s new tower solution.

‘Our aim is to demonstrate that deep-water wind power is commercially attractive within the next four years’, said SWAY founder and CEO Eystein Borgen earlier this year.

SWAY has been granted a licence from the Norwegian Water Resources and Energy Directorate to build a floating offshore wind turbine approximately 7 km off Karmøy on the country’s west coast. Prototype construction is conditional on support from the recently established Norwegian financial support programme for marine renewable energy (Enova).

Finding a customer for this project is nonetheless essential and when that key hurdle is overcome the wind turbine may be up and running in 18-24 months, according to an optimistic Borgen, who said: ‘Our ambition is to demonstrate that such plants in a commercial phase shall be able to supply power at a price competitive with shallow water wind parks.’

The demonstration plant features a 188-metre tower structure, of which 104 metres is submerged. The ballasted tower bottom is anchored to the seabed with the aid of tension leg technology, including a suction anchor. A genuine novelty is a subsea yaw mechanism located between the tension leg and the tower plus wind turbine assembly. The downwind rotor allows the floating tower to tilt (6-8 degrees) due to wind pressure (thrust), and is claimed to be acceptable in terms of yield loss. Transformers and power electronics will be located in the tower, and a subsea cable will connect the plant to the onshore electrical grid.

All-Weather Access

One of the many specific challenges linked to offshore wind power is all-weather installation access. A combination of turbine failure and being unable to access the machine during adverse weather conditions can easily result in extended downtime and subsequent loss of revenue. A common transfer access method to offshore wind turbines on fixed foundations is with the aid of a ‘people mover’ or other service vessel. The rubber-lined bow section is steered firmly against a ‘matching’ steel structure that is often an integral add-on part of the substructure/foundation. Engaging full throttle on the vessel introduces increased friction between it and the corresponding steel structure and slows down wave movements to such an extent that it affords relative safe passage to service personnel.

Among alternative, novel, access technologies is the Ampelmann, developed by Dutch researchers at the TU Delft. The vessel-based self-stabilizing platform actively compensates for all ship motion. Ampelmann systems are already employed in the North Sea and elsewhere and they are claimed to reduce the necessity for jack-ups, semi-subs and helicopters, potentially turning it into a cost effective system, even under marginal weather conditions.

In comparison, according to an expert delegate, floating offshore wind turbine access from a vessel represents a much bigger challenge as waves and wind cause both objects to move continuously. Another challenge may prove to be conducting servicing activities, including the exchange of large and small components (like circuit boards) alike while the entire structure continuously moves in all directions.

The Future’s Out There

During 1991 former technology pioneer Bonus of Denmark (now owned by Siemens) erected the world’s first offshore wind farm comprising of 11 of its 450-kW fixed-speed stall regulated turbines in shallow water at Vindeby. Since then wind turbine size and complexity, average offshore wind farm capacity, distance to shore and water depth have all grown dramatically. Despite the challenges such changes have inevitably wrought, a steadily increasing number of international players continues to reinforce the rapidly expanding wind industry base.

Meanwhile, highly experienced offshore wind market entrants complement established parties with new spirit, fresh ideas and, perhaps most importantly, a strong belief in what they individually and as partners can accomplish. Accelerated availability of reliable high-performance wind technology, fast vessels and clever installation methods, all-weather access technologies, well-trained specialists, and sufficient finance are all essential preconditions for meeting Europe’s ambitious offshore wind objectives.

Equally important for streamlining and speeding up projects and processes is a facilitating role at national and EU political level, with committed leaders taking the responsibility to act. The idea that a winning combination of ambitious renewables (including wind power) and environmental targets can also create many well paid long-term green careers is also fortunately gaining ground. In this respect Swedish deputy prime minister & minister of Enterprise and Energy, Maud Olofsson, deserves much praise. During the conference opening session she inspired the audience by voicing these much needed views and visions.

 Eize de Vries is a wind technology correspondent for Renewable Energy World Magazine.

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Sidebar: New Products

Offshore wind farms could not function without subsea cables transporting the electrical power to shore for feeding into the high-voltage network. Currently four large cable suppliers dominate the world market, including ABB, Prysmian (formerly Pirelli), Nexus, and Draka. The latter has manufactured electricity transport cables for 100 years, including 30 years of subsea cables. The company’s commercial director of subsea cables, Martin Dale, explained: ‘In past years Draka made a large investment in our Norway plant capable aimed at producing a new generation (up to) XLPE 36 kV AC medium voltage cables for the offshore wind market. [Editor's note: Such cables typically extend from the offshore high voltage station (OHVS) – where the cumulative wind farm power output is brought together and transformed to the required voltage level – to shore.]

Draka has now expanded 36-kV AC cable production and in addition offers a complete range of accessories and installation services along with circuit testing or commissioning. We in fact offer a complete solution from design through installation that helps make project management and field installation for our customers more efficient than trying to coordinate several vendors and installers.’

Commenting on dedicated product features Dale says that a lot of effort was put into making the XLPE series more flexible when compared with state-of-the-art equivalents. A second built-in product feature he mentioned explicitly is an extra protective layer aimed at enhancing long-term marine performance.

Hyundai Heavy Industries of South Korea is one of the world’s largest shipbuilders that also manufactures products like power plants, substations, diesel generator sets, electric motors and generators. Hyundai’s renewable energy products portfolio has now been expanded with the addition of wind turbines, and already encompasses solar modules and inverters, and electrical components for electric vehicles. Two sister wind turbine designs, the 1.65-MW HQ 1650 and the 2-MW HQ 2000, originate from Windtec. A third product, a 2.5-MW direct drive turbine originates from market entrant Atlantis. Manufacture of both HQ models commenced in September 2009, while production start of the direct drive turbine is planned for next year.

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Sidebar: Shipping: Evolution or Revolution?

Current installation barges and self-propelled vessels can be roughly subdivided into jack-up type and floating state-of-the-art solutions; evolutionary new developments; and, innovative concepts, each with strong supporters and stern critics.

GeoSea of Belgium is part of the DEME group of companies. This August the company commissioned a new ‘traditional’ four-legged Jack-up barge Goliath, with a length of 55.5 metres and a beam of 32.2 metres. Her deck can be fitted with cranes up to 1200 tonnes capacity and the barge will be employed for the first time installing foundations and wind turbines for the 50 turbine Walney project in the UK in 2010.

Self Propelled

UK-based SeaJacks is originally an oil and gas-focused marine company that recently made the switch to renewables. It now owns two newly built 76 metre long and 36 metre wide self-propelled jack-up sister vessels, Kraken and Leviathan that were commissioned in 2009. The vessels are a design by Dutch marine engineering specialist GustoMSC, and are characterised by four huge triangular truss-type legs and a 300 tonne crane. The vessels have already been contracted until Q3/Q4 of 2011.

German companies Hochtief Construction AG and Beluga Shipping GmbH joined forces by founding Beluga Hochtief Offshore. The partners plan to build a fleet of special vessels capable of building, operating and maintaining offshore wind power plants. This next generation heavy-lift self-propelled jack-up vessel is planned to enter active service by 2012 and can sail at 12 knots. The vessels comprise four lattice-type legs for working in water depths of up to 50 metres. A 1700 tonne crane is fitted around one of the legs. Main hull dimensions are a massive 135 metre length and a 40 metre beam with accommodation facilities for up to 160 persons, including crew. The 8000 tonne cargo load is sufficient to stow eight turbines in the 5 MW+ class.

Floating Innovation

Huisman is a Dutch heavy-lift, drilling and subsea solutions specialist company which is active worldwide. The company has developed an innovative, fast (14 knots), floating Wind Turbine Shuttle concept for installing complete wind turbines. The design is squarely aimed at substantially speeding up offshore installation activities and since the vessel is not jacked up out of the water during installation activities, workability is not limited by this time-consuming operation.

Sharing the characteristics of a SWATH (Small Water plane Area Twin Hull) type vessel, there are two large submerged submarine hull shape pontoons. Each is attached to rather small vertical support columns on top and a deck box located above water. A clever feature is that as soon as the shuttle sails out of the harbour, draft is adjusted and the pontoons become fully submerged, a measure aimed at minimising vessel motion. The floating vessel is expected to be capable of the transport and installation of two complete 5 MW-scale wind turbine top heads of up to 1400 tonnes each in a single operation. An alternative configuration could see the transport and installation of two monopiles, jackets or other substructures/foundations. In the case of jackets, a smaller more cost-effective vessel can perform the pile ramming. Another potential application is offshore turbine exchange. Capable of installing wind turbines up to maximum significant wave height of 3.5 metres, corresponding to an annual workability of approximately 80% under North Sea weather conditions, various technologies are employed to keep a wind turbine virtually stationary in relation to a matching fixed foundation during the lowering process. One specific measure is active heave compensation employed to (further) minimize vessel heave motion, a known and infamous floating wind turbine installation bottleneck. Huisman also designs and manufactures cranes with capacities of 300–1700 tonnes which are used in various wind turbine installation vessels. >>

Wave and tidal power growing slowly, steadily | hydroworld.com

a useful review of current (December 2009) wave and tidal projects in hydroworld.com

< Proponents of wave and tidal power have compared the state of this area of the renewable energy sector with the early days of wind power. The technology has great potential but still must prove itself before it can be widely deployed.

Wave energy technology uses the movement of ocean waves to generate electricity from turbines. Wave power differs from tidal power, which is based on extracting energy from tidal movements and the water currents that accompany their rise and fall.

Experts estimate tidal energy’s advantage lies in its predictability. Wave energy could be more abundant than tidal energy while still being less intermittent than wind or solar power.

Conditions along coastlines or on the ocean surface, however, can be hard on wave and tidal installations. Generation assets must be built with operational hazards such as crashing waves, corrosive salt water and other dangers in mind.

Potential
According to the European Marine Energy Centre (EMEC) at Scotland’s Orkney Islands, the best wave climates—with yearly average power levels between 20-70 kW/m of wave front or higher—are where strong storms occur. The extent to which this will prove practical to harness, however, will depend upon the successful development of near-shore and deep-water technologies.

The most energetic wave resources are along the coasts of the Americas, Europe, Southern Africa, Australia and New Zealand.

The EMEC is one of the world’s foremost proving grounds for wave and tidal technologies and has collected more than 100 wave energy concepts, with many still at the research and development stage.

Wave and tidal technologies can be three to four times more expensive than wind power per megawatt, so many installations were developed and supported with government financial backing.

The United Kingdom remains one of the largest state sponsors of wave and tidal power. The U.K. government granted $3.8 million from an $83 million pot created under the Marine Renewables Deployment Fund, which began in 2004.

More than $33 million has been earmarked for a new Marine Renewables Proving Fund with a further $15.7 million going to develop a Wave Hub off Cornwall and $13.2 million for the EMEC.

Setbacks
Scottish firm Pelamis Wave Power, which changed its name in 2007 from Ocean Power Delivery, launched a project in Portugal called the Agucadoura wave farm. The project consisted of three of the company’s P1-A Marine Energy Converters.

In September 2008, the company installed the energy converters 3 miles off the coast of northern Portugal. In mid-November 2008, all units were removed from the ocean when leaks were discovered in the buoyancy tanks.

Compounding Agucadoura’s woes, Pelamis couldn’t get the financial support to re-launch the units after the technical problems were solved. Following the global economic downturn, sponsor Babcock & Brown withdrew from the project.

By March 2009, Agucadoura was taken offline indefinitely with about $13 million spent on the project.

In February, Pelamis won an order from British renewable company E.ON for the next generation of Pelamis Marine Energy Converters, which the company calls the P-2. The machine will be built at PWP’s facility at Leith Docks, Edinburgh, and tested at the EMEC at Scotland’s Orkney Islands.

Projects
Despite the cancelation and scaling back of some projects following the economic crisis, there are still wave and tidal projects taking shape.

In November, Ocean Power Technologies (OPT) won a $61 million grant from the Australian government for a utility-scale project. The company said work on the 19-MW project is expected to begin by the second quarter of 2010. Further funding will be needed to complete the project, the company said.

OPT’s PowerBuoy floats freely with the rising and falling of offshore waves. The resulting motion is converted with a power take-off to drive a generator. The generated power is transmitted ashore via an underwater power cable.

A 10-MW OPT power station would occupy about 30 acres of ocean space. The technology is scalable up to 100 MW, the company said.

In 2008, OPT won a $2-million award from the U.S. Department of Energy (DOE) in support of OPT’s wave power project in Reedsport, Ore. Major portions of the PB150 PowerBuoy will be fabricated and integrated in Oregon. This was the first award for the building of ocean wave energy systems by the DOE, according to the company.

OPT also has worked with the U.S. Navy on its Deep Water Acoustic Distribution System program. The company is supplying its PowerBuoy technology to the project, which is designed to demonstrate the potential of powering sensor networks over wide areas of the ocean.

Irish tidal energy company OpenHydro won a grant of nearly $3 million in October from Sustainable Energy Ireland’s Ocean Energy Prototype Research and Development Programme. The grant will be used to design and develop a 16-meter Open Center Turbine, Subsea Base and Installation Barge.

The turbine is mounted on the seabed below the ocean waves. Invisible from the surface and silent, the turbines generate up to 1 MW of electricity.

Also in 2009, OpenHydro paired with Nova Scotia Power to unveil a 1-MW tidal turbine to be deployed in the Bay of Fundy. The project will serve as part of Nova Scotia’s tidal power test facility. The Open Center Turbine was manufactured in Ireland by OpenHydro. The turbine will rest directly on the ocean floor using a subsea gravity base fabricated by Cherubini Metal Works.

Oysters and Limpets
Aquamarine Power is a wave energy company whose Oyster Wave Energy Converter has been tested and deployed at the New and Renewable Energy Centre near Newcastle, England.

Oyster is an onshore, commercial-scale pumping cylinder that can deliver more than 170 kW of electricity per unit. A full-scale Oyster uses two pumping cylinders and can deliver in excess of its modeled output of 350 kW.

Oyster is designed to capture the energy found in near-shore waves up to depths of 10 to 12 meters. The device combines new technologies with a hydroelectric power generation system. A commercial farm of just Oyster devices (15 MW) could provide clean renewable energy to 9,000 homes. Aquamarine tested the Oyster in summer 2009 at the EMEC. The company also has an agreement with Airtricity, the renewable energy division of Scottish and Southern Energy, to develop sites capable of hosting 1,000 MW of marine energy by 2020 suitable for deployment of Oyster.

Wavegen, a unit of Voith Hydro with its headquarters in Inverness, Scotland, produces a shoreline wave energy conversion unit called Limpet. The technology is in use and has been connected to Scotland’s power grid since 2000.

The technology used is called an oscillating water column. Ocean waves move air in and out of chambers in a breakwater, which in turn drives Wavegen’s turbine, known as the Wells turbine, to generate electricity.

The 18.5-kW modules are meant for use in breakwaters, coastal defenses, land reclamation schemes and harbor walls.

Wavegen teamed up with Npower Renewables in 2006 to plan a wave power plant for the Scottish island Lewis. The Siadar Wave Energy Project earned the approval of the Scottish government in January.

The project will harness power from the Atlantic waves in Siadar Bay to generate up to 4 MW of electricity. The energy produced each year could supply the average annual electricity needs of about 1,500 homes in the Western Isles.

This article was reprinted from Electric Light and Power’s December 2009 issue >

US Offshore Wind Project Updates | RenewableEnergyWorld.com

The U.S. has made great strides in installing renewable energy projects in the last five years. Renewables account for a larger percentage of U.S. energy generation than ever before and the country has surpassed Germany to lead in installed wind capacity worldwide. Germany and its European neighbors however remain far ahead of the U.S. when it comes to taking advantage of offshore wind resources. That may change in the next few years however as the U.S. regulatory, political and business climate becomes more friendly to wind developers looking to go offshore.

Possibly the largest challenge facing U.S. offshore wind energy developers however is the lack of a stable policy and incentive regime that would bring more players into the industry.

The American Wind Energy Association (AWEA) held its Offshore Wind Workshop earlier this month in Boston to look at the progress that has been made for U.S. offshore wind and what hurdles are left to overcome before the first turbine hits the water.

Project Updates

But just which project will get that first turbine in the water is still a matter of speculation. In total there are four companies with more than 10 projects in different states of development. Each company — Cape Wind, Bluewater Wind, Fisherman’s Energy and Deepwater Wind — is developing projects on the East Coast.

The most well-publicized and possibly controversial offshore wind project in the U.S. is Cape Wind. The project, which has spend eight years in development, would put turbines in Massachusetts’ Nantucket Sound. The project had a lot of opposition to overcome, first from residents in towns on the sound worried it would ruin their views and lead to higher electricity prices, and later from environmental groups concerned with the wildlife impact. These issues have since been addressed.

More recently, a group of Native Americans have said the project would obscure the view from an ancient burial ground, this issue is working its way through the regulatory process and is expected to be resolved by the end of 2009.

Not all of the news about Cape Wind has been negative however. The project was given a favorable Environmental Impact Statement from the U.S. Minerals Management Service, its grid connection in Barnstable, Massachusetts was approved by the Massachusetts Citing Board and National Grid has said that it will negotiate a power purchase agreement for the electricity the project might one day produce.

Jim Gordon, president of Cape Wind said that he thinks the U.S. will see an offshore wind project realized sooner rather later and its one of the keys to fighting the effects of climate change, especially for East Coast cities like Boston where trillions of dollars worth of infrastructure could be damaged or destroyed by rising seas and stronger storms that would be a result of climate change and an economy that needs to put people back to work to grow.

“Right now if Cape Wind was operating we would be producing 422 megawatts of clean renewable energy. That’s 422 megawatts of emissions free power that blows off our coast that will be harnessed by workers from this region,” Gordon said. “The Natural Resources Defense Council has said that Cape Wind represents one of the largest single greenhouse gas reduction initiatives in the United States. We’ve missed out these many years on mitigating many tons of greenhouse gases, but I believe and I hope that the American offshore wind industry is no going to emerge and reach its full potential.”

While Massachusetts has been the first stand of sorts for offshore wind, Delaware might be the spot of the industry’s first major victory. Bluewater Wind, formerly owned by Babcock and Brown, and now a subsidiary of NRG Energy, has leases in place and is set to deploy a series of meteorological (met) towers to determine the best sites for turbines in 2010.

The company also has one 200-MW PPA in place with Delmarva Power and has been selected to provide 55 MW of power to the state of Maryland under a PPA. Bluewater CEO Peter Mandelstam said that the company has interconnection agreements in place and also begun the federal permitting process.  He said the process is easier now as a result of the Obama Administration’s renewable energy goals.

“The most important investor, the most important advocate and the most important public official for offshore wind is President Barack Obama. This industry was dead, but the restructuring of the tax credit, the loan guarantees, the various stimulus provisions and the new regulatory regime totally revived us. We can’t say enough good things about President Barack Obama. He mentioned our Delaware project on Earth Day and going into Copenhagen, he talked about offshore as one of his six pillars to mitigating climate change,” Mandelstam said.

Two other development companies, Fishermen’s Energy and Deepwater Wind are taking different approaches to developing offshore wind projects.

Fishermen’s Energy is taking what it calls a community-based approach to offshore wind. The company was founded by leading Northeast commercial fishing companies so that they could be part of and benefit from the emerging offshore renewable energy industry. The company’s CEO Dan Cohen said that commercial fishing executives knew there was a need for workers to do the construction, operations and maintenance for offshore wind projects, jobs uniquely suited to commercial fishermen who already work offshore and the know waters.

Fisherman’s is involved in two projects: the first is a 350-MW project that the company plans to work on in conjunction with Bluewater Wind and Deepwater Wind. The second is demonstration project located in the waters just off the coast of Atlantic City, New Jersey. This 20-MW project is expected to be built by 2012 and rules for the build out of this project are currently drafted by the New Jersey Board of Public Utilities.

Deepwater Wind plans to do exactly what’s implied by its name, namely build projects 15-20 miles offshore, minimizing the impact of not-in-my-backyard (NIMBY) protests and taking advantage of the stronger wind regimes in those waters. The company has been awarded met tower leases and plans to put them in the water in the next year.

Deepwater, which is part of a consortium developing a project in the waters off Long Island, expects that its first project in the water will be the 30-MW Block Island project off the coast of Rhode Island, which is still pending federal approval. In conjunction with this project, the company is also working to develop Quonset Point, a former U.S. Navy base, into a dedicated offshore wind development hub for the Southern New England area.

Hurdles Still to Overcome

Some challenges remain however. First and foremost is the lack of the vessels needed to install these projects. There are currently no vessels in the U.S. equipped to install these turbines, and while a number of them exist in Europe they cannot simply be brought across the Atlantic Ocean and put to work.

The Jones Act precludes any European based specialty vessel from taking part in commerce in U.S. waters, including the installation of offshore energy projects. While many have suggested that ships used by the oil industry could simply be converted, the cost would likely be prohibitive and U.S. ship builders will have to build wind specific vessels, which Mandelstam said will create thousands of jobs for ports and ship builders that take advantage of the need.

“Seven thousand seven hundred green jobs would be created by building three turbine installation vessels,” he said. “As chairman of the offshore group in the U.S., I participated during the Bush Administration to analyze how we’d get to 20% wind, including 54,000 MW of offshore wind. The choke point is vessels. The Obama Administration has put up a TIGER Grant and the Philadelphia Regional Port Authority has applied and we may gain access to those vessels if there’s an announcement in February 2010.”

Like any other renewable energy or conventional generating assets, in order for offshore wind projects to be built they will need transmission lines and utilities willing to buy the electricity they carry. In some ways this is where the U.S. industry is putting the cart before the horse.

Transmission plans are already underway within the ISO New England region to bring tens of gigawatts of wind power online and the ISO has produced a report for New England’s Governors Association presenting them with a number of scenarios that would bring offshore wind energy to residents of New England.

Even though this transmission capacity is still in the planning stage, utilities are lining up to buy the power once its online. Delmarva Power, National Grid, the state of Maryland and the Long Island Power Authority have already signed power purchase agreements (PPAs) with developers. The biggest advantage that utilities and ISO New England are looking at is the location of offshore wind resources. Who pays for it however remains the big question.

Gordon van Welie, president of ISO New England said that while his company has made a number of transmission investments onshore, they need to wait for a national renewable energy and transmission plan to be in place before a scenario from their report to governors, most likely costing around $6 billion, is chosen and invested in.

“The rhinoceros in the room is the transmission cost allocation,” Welie said, referring to the fact that who pays for the $6 billion in transmission will depend on who is thought to be getting the most benefit from its installation and costs are likely to be split between project developers, grid operators and utilities.

Possibly the largest challenge facing U.S. offshore wind energy developers however is the lack of a stable policy and incentive regime that would bring more players into the industry, from all sides. No matter the policy, be it feed-in tariff, production tax credit, cash grants or renewable energy credits, developers, financiers, utilities and grid operators are calling for more stable incentives and policies.

Long term policy surety would give banks more confidence investing in infrastructure, transmission, construction operations and maintenance vessels as well as generating equipment. Rhode Island Governor Donand Carcieri, who serves as vice chairman of the Governors’ Wind Energy Coalition said that while the states are leading the way, a federal standard is needed to move forward.

“Offshore wind power is one of the most reliable and sustainable sources of energy in the United States, and we are on the path to develop this nation’s first deep water, offshore wind project,” Governor Carcieri said. “The impact of offshore wind is tremendous, from spurring economic development and new jobs to providing stable energy costs, and will move our country towards energy independence.”

via RenewableEnergyWorld.com

Ocean Energy Developments ¦ Renewable Energy World Magazine

18 September 2009

Interest in wave and tidal energy systems is gathering pace as a huge number devices move from the drawing board, through prototype and testing phases and on to commercial developments.

by David Appleyard, Associate Editor London, UK [Renewable Energy World Magazine]

Like many of the current crop of ‘cutting edge’ renewable energy technologies, the concept of extracting energy from waves and tides is not a new one. Indeed, it is well over 100 years since the first tidal wheel was built and the 240 MW La Rance tidal barrage project in Brittany, France, has been operating for well over 40 years. What has changed over the intervening years is the level of urgency with which such projects are now being addressed and the technical achievements by some manufacturers which are making tidal and wave energy a reality.

Alongside growing interest in the UK, USA, and Portugal, countries such as Canada, South Korea, Australia, New Zealand, Brazil, Chile, Mexico and other nations are also expressing support for ocean energy development.

Blessed with one of the longest coastlines of any country in Europe, large tidal ranges and strong winds, it is perhaps obvious that as the home of one of the largest marine energy resources, the United Kingdom should also sport by far the largest concentration of marine power companies in the world. However, while the UK has taken a lead, it is far from alone. According to the IEA-OES, also known as the Implementing Agreement on Ocean Energy Systems which functions within a framework created by the International Energy Agency (IEA), by the end of 2008, more than 25 countries were involved in ocean renewable energy technology development activities. With the deployment of multi-unit wave technology in Portugal, and the commencement of construction of a 260 MW tidal power plant in South Korea standing out as noteworthy.

However, although government support from a few countries has to some extent enabled the ongoing commercialization of ocean energy technologies, a lack of targeted national priorities and policies remains a major barrier. Certainly, the stakes are potentially high.

For example, some analysis suggests that the accessible resource in waters around the UK, taking into account constraints on available sites for a wide variety of reasons, could be as much as 700 TWh per year. Similarly, it has been estimated that the North American marine energy resource could realistically supply some 10% of US electricity demand.

Policy and Government Support

Government engagement with marine technology has been something of a mixed bag. In the UK, for example, support has been relatively high when compared with other sectors. However, Denmark, for instance, ended its wave energy development programme in 2002, leaving the country without a dedicated policy.

Resource assessment is a key step in building marine energy capacity and in one of the more significant developments for the UK industry over the past year, a study to determine the potential for marine energy in English and Welsh waters was announced by the government in April 2009. The new scoping study will look at wave, tidal-stream and tidal range technologies along the English and Welsh coastline. (See caption and credit information for image by clicking on it in the image gallery at the end of this article.)

The devolved Scottish government, meanwhile, is further along, having already produced a preliminary Strategic Environmental Assessment (SEA) for marine energy in Scotland. And, in September 2008, the Crown Estate outlined the application and consent procedure for wave and tidal energy projects in the Pentland Firth, in Scotland, which contains some of the best locations for wave energy in the world. The Firth is the first UK marine power site to be opened up for commercial-scale development, with the aim of developing an installed capacity of more than 700 MW by 2020. The process of granting options for lease over areas of seabed in the Pentland Firth and surrounding area is due to be concluded in the summer of 2009, with deployed as early as 2010 or 2011.

Announcing the decision for England and Wales, the minister for sustainable development and energy innovation, Lord Hunt, said: ‘The marine energy sector has reached a pivotal stage with more and more devices ready to go into the water.’

However, even in the UK the support available has faced criticism. For example, in 2009, the first companies are expected to qualify to receive funding under the Marine Renewables Deployment Fund, which provides £50 million (US$75 million) to support wave and tidal stream technologies in the UK. This sounds positive, but the industry is concerned that the support is only available to companies which have been operating a full-scale prototype for at least three months, a measure which has been criticized given that devices have only recently entered the water. Parliamentary questions found that the entire budget for the Wave and Tidal-stream Energy Demonstration Scheme has remained unspent since it was announced in 2004. Nonetheless, it does set a premium of £100/MWh for electricity produced from marine energy, and this is on top of the retail price of electricity and the Renewables Obligation (RO), which requires utility groups to source a growing proportion of their electricity from renewables. The main support scheme for renewable electricity projects in the UK, the RO is to be revised upwards for marine energy when the government introduces banding for emerging technologies which require more support, such as marine and offshore wind.

In a move first mooted in 2007, ocean energy systems are due to receive 2 ROCs for each MWh produced, double the current level.

Perhaps at least as significant for the industry’s long-term development, in December 2008, the government published a new Marine and Coastal Access Bill, designed to give greater confidence and economic benefits for marine developers through simplification of the legislative framework, and balance the interests of conservation, renewable energy and other marine interests. Through the legislation, the government intends to set up a new Marine Management Organisation (MMO) to oversee the majority of marine planning applications and the bill will also create a strategic marine planning system.

Elsewhere in Europe, in Portugal for example – which boasts the world’s first commercial marine energy installation – a feed-in tariff for wave energy was established in 2007 mandating a euro260/MWh price for the first 20 MW installed. While in the US, members of both houses of Congress are calling on the Department of Energy (DOE) to allocate $250 million of the $2.5 billion in stimulus funding for renewable energy research and development to the emerging marine renewable energy industry.

And, in a 2009 Earth Day speech President Barack Obama announced that the Department of the Interior has now finalized a long-awaited framework for renewable energy production on the US Outer Continental Shelf (OCS). The framework establishes a programme to grant leases, easements and rights-of-way for orderly, safe and environmentally responsible renewable energy development activities, such as the siting and construction of wave farms on the OCS. Alongside growing interest in the UK, USA, and Portugal, countries such as Canada, South Korea, Australia, New Zealand, Brazil, Chile, Mexico and other nations are also expressing support for ocean energy development.

Wave Energy Generators

Though still at an early stage of development, the marine energy sector has already seen a number of technologies progressed to the point of commercial installation. The rapid emergence of new machines, continuous development of more established ones, and the wealth of on-going R&D leaves no real consensus over which designs will ultimately emerge to produce electricity from the ocean most efficiently and cheaply, and yet which remain sufficiently robust to survive the rigours of a life at sea. Indeed, a large number of competing, sometimes unexpected, designs for producing wave and tidal power all but swamp the horizon.

Oscillating water column (OWC) is one technology that is being explored by a number of companies.

For instance, Orecon’s wave to energy buoy is based on a multi-resonant chamber (MRC) oscillating water column and a HydroAir bi-directional air impulse turbine supplied by Dresser-Rand Company Ltd, the two have also signed a memorandum of understanding to optimise the design for the device. Orecon has also signed an agreement with Portuguese developer Eneólica to establish a Joint Venture company to build and deploy Orecon’s first full-scale 1.5-MW MRC buoy in a grid-connected installation. Once the first unit is commissioned, two further MRCs will be added, increasing output to 4.5 MW and making it the world’s largest operating wave farm to date. The partners say they intend to develop further sites in Portugal over the next 10 years.

Another OWC design that is subject to advanced testing and planning is the Danish development Wave Dragon. A prototype project was installed in Nissum Bredning as early as 2003 and Wave Dragon plans to deploy a 7-MW Wave Dragon off the coast of Milford Haven in Wales in the spring of 2010. The company also plans to install 10 machines in Portugal between 2011 and 2012 and an additional 10 machines in an array off Wales in 2013. OWC-type machines of various designs and to varying degrees of success have also been built in Australia, Scotland, Norway, Japan, India, and Portugal.

One of the most commercially advanced offshore wave power devices is the Pelamis machine (see image, above), a 750 kW, snake-like machine developed by Edinburgh-based Pelamis Wave Power (PWP). Following a period of testing at the European Marine Energy Centre (EMEC) in Orkney, the world’s first commercial wave energy installation, a 2.25-MW development in Portuguese waters has been developed with energy company Enersis. The three machines, near Póvoa do Varzim some 5 km offshore, are known as the Aguçadoura wave farm.

Another example comes from New Jersey, USA-based Ocean Power Technologies (OPT) and its PowerBuoy. It is due to install one of 150 kW devices at EMEC, while in the longer term it intends to develop a 5-MW wave farm, consisting of buoys arranged in a grid, planned as part of the UK’s Wave Hub project. The device, which uses waves to move the buoy up and down converts the resultant mechanical stroking via a power take-off to drive an electrical generator, is expected to be ready for deployment and grid connection in 2009. In the past year OPT says it has reached two major manufacturing milestones in the development of its flagship PB150 PowerBuoy device with projects at locations including Reedsport in Oregon, Victoria, Australia and in the UK.

The design is similar in concept to that of Wavebob Ltd of Ireland, which has signed a co-operation agreement with Vattenfall AB for the possible development of a 250-MW demonstration project using its Wavebob device.

Another device that uses the linear motion of waves to generate energy is Trident Energy’s machine. This machine is solidly anchored, rather than self-reacting using inertial forces like OPT and Wavebob, and floats are used to drive linear generators. Trident Energy is currently in the final stages of preparing for a year-long deployment of a fully functional test rig in the North Sea off England’s east coast. The test rig will generate about 20 kW from eight full scale linear generators.

Other designs of wave energy devices include the Archimedes Wave Swing developed by Scotland’s AWS Ocean Energy, Voith Siemens Hydro Power Generation’s WaveGen and Isle of Man-based Renewable Energy Holdings plc (REH) with its CETO device.

The CETO uses a submerged piston to deliver high pressure water to shore which is then used in conventional hydro technology. Test deployment of a full-scale CETO III unit is due for completion in 2009, with commercial rollout anticipated shortly thereafter.

In April 2009 Aquamarine Power announced that it is to commence installation of its 350-kW Oyster wave energy machine at EMEC in the summer of 2009 and with Airtricity, the renewable energy division of Scottish and Southern Energy, a deal is place to develop sites capable of hosting 1 GW of marine energy by 2020. The device consists of an oscillating flap, which, as with the CETO design, pumps high pressure water through an on-shore turbine to generate electricity. (See image, left.)

Many novel wave devices, such as the Green Ocean Energy Ltd Wave Treader machine, which attaches to offshore wind farm monopiles and shares infrastructure, or the rubbery submarine-like tube that is the Anaconda from Checkmate Seaenergy Ltd are at far earlier stages of development than other designs. Nonetheless, they represent interesting avenues for the development of commercial wave energy.

Tidal Current Energy

As with wave energy, there are a variety of competing devices which generate electricity from tidal currents. These can broadly be divided into those that operate in shallow shoreline water and those that work in deep fast-moving tidal channels. Most of the devices approaching commercialization are in this second category.

One of the most commercially advanced of the tidal companies is Marine Current Turbines (MCT). The company has installed its new SeaGen device, a two-rotor machine capable of generating 1.2-MW, in Stangford Narrows in Northern Ireland. In July 2008, having briefly exported power the grid, it became one of the world’s first commercial-scale tidal turbines installed and operating.

MCT intends to deploy a series of SeaGen devices in projects off Anglesey and on the Canadian seaboard within the next few years, and has already secured backing of npower Renewables to execute plans for a 10.5 MW-tidal farm scheme in an area of 25 metre-deep open sea known as the Skerries, off the north-west coast of Anglesey. Subject to successful planning consent and financing, the tidal farm could begin commercial operations as early as 2011 or 2012. It has also agreed a partnership with Canada’s Minas Basin Pulp and Power Company Ltd for a demonstration project in the Bay of Fundy, Nova Scotia.

The company followed this up by applying for a lease from the Crown Estate to deploy up to 50 MW of its machines in the Pentland Firth. Subject to financing and securing the necessary approvals, the company says it expects to install up to 50 MW by 2015.

In another tidal turbine development, utility group Scottish Power has teamed up with Hammerfast Strøm of Norway to install a 1-MW full-scale prototype tidal turbine in Scotland, with a view to eventually developing tidal farms of 100 MW or more. Manufacture of the prototype began in 2008, with installation during 2009. Using the device Scottish Power also plans to install three tidal energy farms off Scotland and Northern Ireland with a total capacity of up to 60 MW, which could be operational by 2011, the company says. The facility will use the Lànstrøm tidal turbine, developed by Hammerfest Strøm AS.

Meanwhile, Irish company Open Hydro has been testing their 250 kW open centred, rim generator device, at EMEC in the Orkneys since September 2008. And, in April 2009, the company awarded a contract to Cherubini Metal Works of Dartmouth, Nova Scotia, for the supply of a subsea base to support the installation of its first tidal turbine in Canadian waters. The unit is scheduled for deployment this autumn in the Minas Passage of the Bay of Fundy and the project is being developed in partnership with Nova Scotia Power and with support from Sustainable Development Technology Canada (SDTC). Work is expected to complete in August 2009. Open Hydro has also partnered with EDF in plans to install four to 10 of their turbines off the coast of Brittany and the company has also announced that it has secured a contract to develop a pilot project for Snohomish County Public Utility District, a public utility in Washington State, USA. The contract to develop a tidal project in the Admiralty Inlet region of the Puget Sound involves the installation of up to three turbines. Installation is expected to begin as early as 2011.

Elsewhere in the USA, a number of marine current energy trials are underway, for example Verdant Power has tested six of its 35-kW turbines in New York’s East River, but it is only in the last year that the first commercial hydrokinetic turbine has been installed. Hydro Green Energy LLC completed the installation of one of two surface-suspended turbines at what it claims is the United States’ first-ever commercial hydrokinetic power project, near the City of Hastings in Minnesota, in late 2008.

Another tidal stream turbine comes from Lunar Energy. The company has forged an alliance with EON to develop an 8 MW project off the Welsh coast using 1-MW horizontal-axis systems developed by Rotech Tidal Tubines (RTT). The development follows Lunar Energy’s March 2008 agreement with Korean Midland Power Co (KOMIPO), to supply a giant 300-turbine field in the Wando Hoenggan Water Way off the South Korean coast. The field is expected to supply electricity by 2015.

In the southern hemisphere, in March 2009 Singapore’s Atlantis Resources Corp signed a co-operation agreement with Norwegian utility group Statkraft to develop tidal current electricity generation projects in Europe using its 400-kW Nereus II and 500-kW Solon turbines. In December 2008, Atlantis signed the world’s largest tidal energy generation agreement with Hong Kong-based CLP Group, increasing Atlantis’ electricity-generating project pipeline to 800 MW. The commercial launch of a 2-MW Solon turbine is expected soon.

A Creative Explosion

One key characteristic of the marine energy sector which makes it all but impossible to pick a winning technology is the burst of creativity that has seen a wealth of novel designs emerge.

As with wave energy devices, a number of novel designs have emerged which seek to generate energy from tidal currents. One such device is under development by Australia’s BioPower Systems. The so-called bioSTREAM is based on the highly efficient propulsion of Thunniform-mode swimming species, such as shark, tuna, and mackerel and the machine mimics the shape and motion characteristics of these species, but is a fixed device in a moving stream. In this configuration the propulsion mechanism is reversed, and the energy in the passing flow is used to drive the device motion against the resisting torque of an electrical generator. Systems are being developed for 250 kW, 500 kW, and 1 MW capacities to match conditions in various locations.

Meanwhile, World Energy Research and Blue Energy Canada have signed a joint agreement under which World Energy Research would finance the development of Blue Energy Canada’s first 200 MW commercial tidal power project at a cost of roughly $500 million using a novel vertical-axis hydro turbine.

There are also other types of ocean energy that have yet to be explored to any great extent and which include technologies such as those which exploit an osmotic gradient or so-called Ocean Thermal Energy Conversion (OTEC) systems, which rely on a thermal gradient. It may be hard to pick a technology winner, but the vast quantities of energy potentially available suggests that a winner will indeed emerge.

David Appleyard is associate editor of Renewable Energy World.

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Sidebar: Tidal Barrage Development

The precise predictability of the tides and the vast quantities of energy potentially available has prompted continued interest in tidal barrage technologies.

Although only a very few tidal barrage projects of any size are currently operating, alongside La Rance is the 18 MW Annapolis Royal Tidal plant in Canada’s Bay of Fundy which has been operating since 1984, a number of smaller schemes do exist. In China, for example, the IEA reports that there are at least seven tidal barrage plants with a capacity of 5 MW or more.

In addition, plans for more tidal barrage development are well underway. In South Korea, the Sihwa Tidal Power Plant project would generate 260 MW, making it the largest such project in the world. The approximately $250 million project is already under construction and will consist of 10 turbines and is expected to be completed in 2009. South Korea has also announced plans for other tidal barrage schemes, including the 520 MW Garolim Bay development. This installation is expected to be completed some time in 2014.

 Other countries blessed with large tidal ranges and suitable geography include the USA, India, Mexico and Canada.

 In the UK, the Severn Estuary with its 14-metre tidal range has been the site of proposed tidal barrage schemes for well over 100 years and with a potential generating capacity estimated at more than 8 GW, some 5% of current UK requirements.

 Subject to an on-going two-year feasibility study led by consulting firm Parsons Brinckerhoff, significant environmental, not to say engineering and financial, challenges remain.

 So far, a public consultation has arrived at a proposed shortlist of five schemes from 10 original proposals, which includes a mixture of barrages and tidal lagoon schemes.

 Elsewhere in the UK, feasibility studies have considered tidal barrage schemes in the Eastern Irish Sea, the northwest of England – including the Solway Firth, and the estuary of the River Mersey, among other locations.

via Renewable Energy World Magazine