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November 5, 2014
By Pete Danko
Wave energy – recently characterized by one leading academic in the field as being “in kindergarten” compared to fossil fuels – isn’t about to graduate to the big time, but the effort to build a meaningful industry in the U.S. could advance several grades in the next few years. Not one, not two, but at least three full-scale wave energy converters, all intended to produce significant grid power when deployed in arrays, are now in line to be tested in Hawaii.
Columbia Power Technologies told Breaking Energy that it had signed a $3 million contract with the U.S. Navy that will support deployment of the company’s StingRAY device offshore from Marine Corps Base Hawaii Kaneohe Bay. Just last week the U.S. Department of Energy said it had selected Northwest Energy Innovations and Ocean Energy to receive a total of $10 million to deploy devices at the same test site, on the windward side of Oahu.
The Wave Energy Test Site in Hawaii will feature two grid-connected berths, and it wasn’t clear when exactly the three devices that have landed spots would go in the water. Industry sources said, too, that there could actually be a fourth device bound for Hawaii, through another Navy contract, but that remained to be confirmed. For his part, Columbia Power CEO Reenst Lesemann said his company expected to begin its year-long Hawaii trial in the second half of 2016.
Columbia Power’s corporate offices are in Charlottesville, Virginia, but its technology is rooted in Corvallis, Oregon, where the company’s engineering staff is located. That purely American profile sets Columbia Power apart from the other two companies that will take advantage of the first grid-connected wave test facility in the U.S. for utility-scale devices.
Northwest Energy Innovations’ wave energy converter, called Azura, was conceived in New Zealand, hence the original name for the device: WET-NZ, for Wave Energy Technology-New Zealand. The Portland, Oregon, company has been working with the Kiwis for several years on U.S. activities, and headed up a six-week test – with no grid connection – of a half-scale version off Oregon in 2012. That led to DOE money for a longer test in Hawaii at an already existing shallower-water test site. That test is expected to proceed shortly, setting the stage for the full-scale test later.
Ocean Energy is from Cork, Ireland, although the company and DOE give its U.S. division a Sacramento location, as was the case last year when it won a $1 million DOE technology grant.
As for the devices themselves, the StingRAY and Azura are broadly similar – both are point absorbers, the most common format for deep-water wave energy generation, meaning they use a mechanism floating at the ocean’s surface to absorb the energy of waves from various directions.
The megawatt-scale StingRAY and the Azura have many differences, from structural to mooring, but a key factor separating them is how they actually turn motion into power: Columbia Power’s StingRAY uses a direct-drive system that the company believes offers simple, highly efficient operation. Azura, meanwhile, drives its generator with a high-pressure hydraulics system.
Ocean Energy uses an entirely different technology, known as oscillating water column, in which rising and falling waves send water in and out of a chamber, forcing air through a bidirectional turbine to produce energy. A shore-based application of the same basic technology was the basis for the world’s first wave power installation, Islay Limpet in Scotland.
Ocean Energy has conducted extensive testing in Europe, and had talked two years ago about installing a 1.5 MW device at a test facility in England, but that test has not come to pass.
All of these devices – along with others being tested at the European Marine Energy Centre in Scotland and elsewhere – are striving against some tough odds to advance the proposition of wave energy for utility-scale generation. They’re untested and expensive, and other ocean users and some greens fret about their impact. Still, the resource is huge and there has been enough lab work, pilot projects and smaller-scale demonstrations to suggest commercially viable devices will emerge. It’s just likely to take a long time, longer yet without strong policy support.
Meanwhile, other players have been aiming smaller, with nearer-shore devices that might power isolated coastal communities that currently rely on expensive imported diesel, or could provide power in emergency situations. In Oregon in September, one such developer, M3 Wave, completed a two-week test of their seafloor-based device, and Resolute Marine Energy is expected to test a near-shore device in the same vicinity next year. That site, however, has no grid connection.