Wave and tidal establishes presence in the U.S.

George Marsh

There are few contexts in which the U.S. can be described as a minnow, but in terms of exploiting wave and tidal energy it is – for the moment. George Marsh looks at the sector as it tries to establish a foothold in the states.

This qualification as a minnow is appropriate because there are signs that things might change. If the sector manages to build on present small beginnings, it is conceivable that the US could grow from minnow to mighty beast, just as it is now doing in wind. Given the country’s long Atlantic and Pacific coastlines and huge ocean resources, along with large tides in some areas, there is plenty of potential to be tapped.

Riding the waves

Until recently, there was no grid-connected wave power generation anywhere in the country. That changed when Ocean Power Technologies (OPT) completed the first-ever grid connection of a wave energy device in the USA. The connection, in September, was between an OPT PowerBuoy system and the grid serving the US Marine Corps in Hawaii.

PowerBuoys are floating buoys anchored to the sea bed, power being derived from the buoy vertical motions induced by waves. A spokesperson said the connection at Hawaii demonstrated the ability of the PB40, a PowerBuoy capable of delivering 40 kW at peak, to send utility-grade renewable energy to the grid in a manner compliant with national and international standards.

First deployed in December 2009 in 100 ft of water, the Hawaii PowerBuoy has clocked up over three million power take-off cycles in 4400 hours of operation, as part of a US Navy project. A PB40 prototype had already demonstrated two years of operation in ocean conditions off Atlantic City, New Jersey.

Between them, these demonstrations bode well for the wave farm OPT intends to build some 2.5 miles off Reedsport, Oregon, on the US West Coast. For this, the USA’s first proposed commercial wave farm, OPT will next year install one of its P150 PowerBuoys (150 kWp), helped by a funding contribution from the Department of Energy (DoE).

This, however, is just a start in a longer-term project to locate 10 PB150s off Reedsport to produce some 4140 MWh/yr for the Pacific Northwest Generating Cooperative (PNGC). There are 14 stakeholders in this venture. After that there could be further expansion, with the potential to deliver up to an estimated 50 MW to the grid.

Meanwhile, OPT is working on its next-generation buoy, the PB500 (500 kWp) which will form the basis for another intended wave park in Oregon, this time off the towns of Coos Bay and North Bend. This larger park would comprise up to 200 PowerBuoys with 20 undersea sub stations and a submarine cable to deliver generated power the 2.7 miles ashore and into the PNGC grid. This plan, if it goes ahead, could see the United States maintain its reputation for scale by establishing the world’s largest wave energy project.

Other OPT buoys are being deployed at Santona in Spain, at the Hayle Wave Hub off North Cornwall, UK, and in the Orkney Isles, Scotland. There are also projects in France and Portugal and OPT has a working base at Warwick in the UK. For Hayle, the company is planning a 3 MW array of PowerBuoys and sees this as a valuable monitored phase of its technology development.

With its activities, this 16-year-old company is helping to put Oregon in the vanguard of any movement in the USA to implement wave power on a utility scale. It is a repeat of the by-now familiar US pattern whereby individual states lead the way in encouraging renewables, with Federal policy being a less predictable and often intermittent affair.

According to the American Council On Renewable Energy (ACORE), the Oregon Wave Energy Trust tempts enterprise with an industry matching grant program, while the state also offers tax and other incentives plus a relatively favorable legislative environment.

Oregon’s Renewable Portfolio Standard (RES) mandates that, by 2025, electricity suppliers must be generating 5-25% of power from qualifying renewable energy sources – the exact figure depending on the utility’s size. The Oregon Public Utilities Commission offers inducements similar to feed-in tariffs for power produced from renewables. Rebates for renewable projects, a loan program and a public benefit fund are among other blandishments.

Oregon may be a pathfinder, but it is not alone in wanting to exploit its wave power potential. Neighbor Washington State is reportedly contemplating production incentives as part of a package of inducements to encourage wave and ocean resource developers. On the other hand, to the south, California has not specifically targeted its substantial wave and tidal potential, despite policies that are highly favorable to renewables overall.

Perhaps with its abundance of solar, hydro-electric, wind, geothermal and biomass resources, it sees little need to do so.

Over on the East Coast, Rhode Island has announced plans for a US$45 million, 1.5 MW pilot wave energy project near Block Island. The initial phase of the program would be followed by a further 15-20 MW facility off the mainland.

Neighboring Massachusetts, though, has no known plans despite its pre-eminence in clean energy research and innovation, as well as considerable wave and tidal resources. According to ACORE, barriers to utility scale prospects include siting concerns, confusing permitting requirements and unclear interconnection standards – a story familiar in the context of other renewables nationwide.

However, given its academic and innovation resources, educated workforce and financial services assets, Massachusetts should be able to overcome these barriers, perhaps clearing the way for commercial-scale wave power exploitation.

Time to turn the tide

Tidal energy, like wave power, has significant potential in the United States but it has hardly begun to be tapped. New York, however, stands out as having a multi-phase tidal power project in development, one of them being America’s first tidal project. Verdant Power has had a test project running in New York’s East River since 2007.

A submerged tidal turbine, dubbed a free-flow kinetic hydropower system by Verdant and first installed in the River in 2006, was the first of 6 turbines placed in an array over the subsequent two years as part of the Roosevelt Island Tidal Energy (RITE) project.

This demonstration phase established the ability of the system, with its 5 m (~16.4 ft) diameter rotors, to consistently supply power to the grid, delivering 70 MWh of energy to two end users in 9000 hours of turbine operation.

The RITE installation stands as the world’s first grid-connected array of tidal turbines. Plans exist for building a 30 MW array of tidal turbines in a third project phase that would deliver generated power commercially to local customers. Project partners include the New York State Energy Research and Development Authority, the New York City Economic Development Corporation and the National Grid.

Verdant Power is also turbine supplier under the Cornwall Ontario River Energy (CORE) project that will harness flow in the St Lawrence River to generate up to 15 MW of power locally. While this river project is in Canada, it does help establish Verdant as a leading North American tidal generation player. More projects are planned in Canada and in California.

Verdant is also assessing tidal resources in the UK, South America, China and India. The company describes its turbines as simple and scalable and claims they have minimal environmental impact. It says its turbines are appropriate for harnessing not only tides but also the steadier currents found in rivers. Its machines are of the horizontal axis, three-blade rotor form that has come to dominate the wind energy industry; it will be interesting to see whether in the long term this form, with a truncated rotor to allow for the much greater density of water than air, proves just as optimum for capturing tidal energy.

In 2008 Verdant was awarded DoE funding to develop its system under the Department’s Advanced Water Power program. It is working with the National Renewable Energy Laboratory (NREL), Sandia National Laboratories and the University of Minnesota’s St Anthony Falls Laboratory.

On the Pacific side, in Washington State, the second of the USA’s two active tidal programs is in progress. During late September, a crew controlling remotely operated vehicles from an anchored barge was investigating the seabed off Whidbey Island in Puget Sound to establish its suitability for supporting turbines made by Ireland’s OpenHydro, which would be deployed on large flat tripod mounts resting on the seabed.

Meanwhile, officials from Snohomish County, within which the scheme is located, were striving to secure the necessary licenses and funding approvals whilst also drawing up plans for the demonstration-scale project, which they expect to be implemented in 2012. The DoE is granting US$10m for the scheme, enough to cover about two thirds of its estimated cost.

Public Utility District Commissioner Tom Olsen, comments: “We’re excited to be leading the way in research of this innovative technology source to meet the needs of the fastest growing areas of the Pacific Northwest.”

Results from the project, in which slow-turning, 10 m (~32.8 ft) diameter turbines will be connected to the local power grid, will influence whether tidal flows in other parts of Puget Sound, such as Deception Island, will similarly be harnessed. Proponents of other schemes include the US Navy, which is planning a one-year research study in the Sound also using Verdant Power technology.

Some of the country’s – indeed the world’s – strongest tides are to be found on the East Coast, up around New England. The Atlantic coast of the state of Maine is at the southern end of the Bay of Fundy where the tidal range can reach a startling 50 ft in the north near New Brunswick in Canada, while being a hardly modest 11-20 ft (depending on location) further south on the US side of the border.

It is no surprise that several turbine producers are seeking to tap into this tidal powerhouse. OpenHydro, for one, is active on the Canadian side working with Nova Scotia Power and the Fundy Ocean Research Center for Energy.

Maine has numerous bays and islands within its rocky 230-mile coastline to concentrate tidal forces. Off the town of Eastport, where the tidal range is up to 19 ft, flows in the Western Passage of Passamaquoddy Bay become particularly strong.

This is where the Ocean Renewable Power Company is planning a trial project with submerged turbines. President and CEO Chris Sauer, says: “It’s critical to prove through this testing that our turbine generator is commercially viable. It has the potential to catapult us to the front of the tidal energy industry while putting Maine on the world map as far as tidal energy is concerned.”

Maine is already New England’s largest producer of renewable energy as a whole, and hopes that exploiting its tidal power will help it strengthen this position still further. It is noted for its renewable energy supportive policies and incentives including eased permitting requirements, an ambitious RPS, tax and production incentives, net metering and sustained R&D.

Choppy waters

It seems that, with the mainly trial and demonstration phase projects outlined above, we could be witnessing the start of a new strand of renewables industry in the United States. The natural resources are certainly there. Wave power alone has the potential to supply 30 GW of electricity, according to DoE. Tidal power, while concentrated in certain areas and variable (though reliable and predictable) is also a major resource.

In a study encompassing five states, the Electric Power Research Institute (EPRI) estimates there to be 300 MW of technically feasible tidal potential, as well as a theoretical potential of 3800 MW in Alaska. Energy could also be extracted from the steady flows of rivers and offshore currents such as the Gulf Stream and Florida Current. Energy consultancy Navigant Consulting Inc estimates that untapped hydropower resources in the US, both inland and ocean, total more than 400 GW – though this includes conventional hydro-electric power.

Now that carbon reduction is a mainstream issue and with the Obama Administration broadly in favor of renewables, the omens are better than for some time. With each new setback for fossil fuels – witness, for instance, the recent Gulf of Mexico oil spill – political will is growing behind renewables and investment is following, not least via the American Recovery and Reinvestment Act (ARRA) stimulus package, a portion of which is earmarked for renewables.

Nonetheless, the waters are still choppy. At this embryonic stage, wind and tidal enterprise is especially vulnerable. A lack of long-term policy continuity that has plagued renewable enterprise to date leaves investors and companies uncertain of future financial returns. A situation where tax and other incentives can be voted in one year, and cut off the next, hardly encourages investor confidence.

If there was ever any doubt that renewable industries need seed-funding support in order to become established, energy consultancy Navigant Consulting’s finding that investment in wind fell by 73-93% in years when the Federal Production Tax Credit (PTC) was allowed to expire should dispel it.

An ‘on-off’ support regime makes entrepreneurs cautious, retards momentum and inhibits supply chain formation. A related issue is that those renewable technologies that have become mainstream tend to attract most of the available investment, leaving little for emerging technologies viewed as higher risk.

Then there are the bureaucratic and practical obstacles project-initiators have to negotiate before they can start implementing their schemes.

Obtaining the necessary licenses can be a protracted affair requiring impact studies related to the environment, wildlife, infrastructure and the effect on local populations.

In Oregon, for instance, Ocean Power Technologies was given the thumbs up for its project by the Federal Energy Regulatory Commission (FERC) only after an extensive permitting process. There are two levels of bureaucracy to be satisfied: One at the Federal level and the other in the state where the project will be implemented. States vary in their degrees of support, permission requirements and general attitude to renewables.

Costs in the early stages of technology implementation are invariably high. Navigant has projected installed costs of US$2500/kW for wave power and US$3000/kW for tidal in-stream energy conversion (TISEC), based on EPRI cost estimates. Only emerging experience will determine how accurate these estimates are, and much remains uncertain.

Other ‘unknowns’ include the practicalities and costs of providing the necessary plant-to-shore connection infrastructure in the arduous marine environment, and the costs of operating and maintaining wave and tidal plants once they are up and running. Fear of the unknown is aggravated by the fraught financial times we live in.

But wave and tidal energy proponents can take heart from the fact that the wind and solar communities have succeeded in building momentum despite similar hindrances. Moreover, a number of initiatives are aimed at making life easier for project initiators.

For example, in 2009 the Maine authorities and the FERC signed an agreement to streamline Federal and state licensing processes for offshore ocean energy and wind projects – the first agreement of its kind on the East Coast. This acceleration of often slow and arduous processes should shorten times from project conception to implementation, thereby reducing risk and cost for pioneer organizations.

As in Europe, environmental concerns loom large. Environmentalists object to plants over concerns about scenic coastlines and local ecosystems.

Coastal states are understandably eager to protect fishing interests and fear the effect turbines and other systems might have on sea creatures. EPRI is investigating the impact of emerging technologies, plus existing hydro-electric power, through its Waterpower program, with fish passage protection being a particular focus. Its R&D program for 2011 includes continued development of the Alden fish-friendly turbine which, although seen primarily as a potential solution for hydro-electric schemes where dams impede fish passage, could conceivably have application in tidal arrays as well.

Overall, the situation is finely balanced. Time will tell whether US wave and tidal power will grow from their present minnow status to the mighty beast the potential suggests, or whether they will remain a tiny creature occupying a niche role. Another question is how they will relate to other waterpower resources, including ocean thermal and conventional hydro-electric.

Henceforth, now that a few pioneers are offering a glimpse of a new and promising direction for waterpower, progress will be a matter of will, politics and investment. Awareness that the UK and other parts of Europe are snatching a lead in this infant renewables sector could stimulate US policymakers to rustle up all three, and the world knows that the US can scale up rapidly when determined to do so.

About the Author:
George Marsh is a technology correspondent for Renewable Energy Focus.

Share this article

More services


This article is featured in:
Wave and tidal energy