By Alison LaBonte
A new initiative, called the Wave Energy Prize, was announced in 2015 during the keynote address at the annual National Hydropower Association conference, International Marine Renewable Energy Conference, and Marine Energy Technology Symposium. This announcement represented a milestone for the U.S. Department of Energy’s (DOE) Wind and Water Power Technologies Office – the commencement of its first public prize challenge, with a total prize purse of US$2.25 million, stemmed from realizing that a technology leap in the efficiency of wave energy converter (WEC) devices was needed to jolt wave energy onto a pathway toward sweeping cost reductions. This pathway could ultimately make wave energy, which is still in the early stages of technology development, competitive with more traditional forms of energy, paving the way to large-scale implementation within a generation.
Fast-forward just one year – 92 teams registered for the Wave Energy Prize, with 66 of these submitting technical data for review by the prize’s judging panel. In August, 20 teams were named official qualified teams and began developing 1/50th scale models of their WEC devices. Between August 2015 and January 2016, they submitted revised technical submissions, numerical modeling results, model design and construction plans, and the results from their 1/50th scale model tank testing as requirements to be considered for the next round of evaluation.
On March 1, DOE announced nine teams as finalists and two as alternates, all of which will continue their quest to double the energy captured from ocean waves and win a prize purse totaling more than US$2 million. Each of the finalists will now receive up to $125,000 of seed funding from DOE, with alternates receiving up to $25,000 to develop 1/20th scale models of their WEC technologies. These models will be tested at the Naval Surface Warfare Center’s Maneuvering and Seakeeping (MASK) Basin at Carderock, Md., beginning in the summer of 2016.
ACE – a benefit-to-cost ratio – was selected by Wave Energy Prize personnel as a metric appropriate for comparing low technology readiness level WEC concepts when there is not enough data to calculate the levelized cost of energy – itself a cost-to-benefit ratio – from a device. ACE is determined by dividing, in essence, the wave energy extraction of a WEC by its structural cost.
“The qualified teams’ efforts resulted in some very promising technologies for the judges to evaluate,” said Wes Scharmen, principal investigator at Ricardo Inc. and chief judge of the Wave Energy Prize. “Based on our preliminary evaluation, the data indicates that many of the teams identified as finalists have the potential to achieve the ACE threshold, and thus the potential to exceed DOE’s program goal.”
Finalists were determined based on their potential to achieve doubling of the current state-of-the-art ACE value of 1.5 meters per million dollars (m/$M) to 3 m/$M during 1/20th scale tank testing at the MASK Basin, making them eligible to win the grand prize of $1.5 million.
Below is information about the technologies vying to win the Wave Energy Prize, listed both in alphabetical order (and in the teams’ own words, provided before completion of 1/50th scale tank testing):
- AquaHarmonics (Portland, Ore.) – AquaHarmonics’ wave energy device is a point absorber consisting of a simple power take off (PTO) system mounted in a cone/cylinder shaped hull with a single mooring line that has a power cable at its core;
- CalWave (Berkeley, Calif.) – CalWave’s device is called the WaveCarpet. This approach was inspired by the ability of a muddy seafloor to effectively absorb overpassing ocean waves within only a few wavelengths. The unique converter design uses a synthetic-seabed carpet that has the ability to extract wave energy the same way;
- m3 Wave (Salem, Ore.) – m3 Wave’s NEXUS is a mid-column variant of its DMP/APEX submerged pressure differential technology. The system harnesses the pressure wave under ocean swells while stationed above the ocean floor, but still safely under the surface, protected from surface hazards;
- Oscilla Power (Seattle, Wash.) – Oscilla Power’s Triton™ is a two-body point absorber, consisting of a large surface float connected by flexible tethers to a submerged heave plate. As ocean waves excite the surface float, it reacts against the heave plate, generating tension changes in the tethers. These tension changes are applied to a linear drivetrain, consisting of a hydrostatic load amplification system and a variable reluctance generator that translates the low displacement, high force mechanical energy input into electrical energy;
- RTI Wave Power (York, Maine) – The RTI F2/F2D development objective is to achieve the lowest capital cost per megawatt of output combined with secure survivability in severe seas. To concurrently capture a majority of both heave and surge energy, the RTI F2/F2D utilizes elongated swing arms to attach its EWFP float directly to a generator in its motion-stabilized floating twin vertical spar frame, which constrains the float to move concurrently upward (for heave capture) and rearward (for surge capture) on wave crests and return forward and downward on wave troughs;
- Sea Potential(Bristol, R.I.) – The DUO is a new design concept that simultaneously captures power from both the heave and pitch/surge motions induced by wave action. DUO’s patented configuration, which connects oscillating bodies with angled pre-tensioned cable linkages and a PTO system, enables power capture from pitch motions to be exploited simultaneously with heave motions. DUO’s primary power absorption is achieved by damping the relative heave and rotational motions of the oscillating structures;
- SEWEC (Redwood City, Calif.) – SEWEC is an oscillating water column (OWC) WEC – a device that operates in a similar fashion to the most successful shore-based wave energy convertors. The SEWEC device extends the proven OWC concept, enabling devices to be moored offshore in a much wider range of locations than conventional shore-based devices.
- Wavefront Power (Research Triangle Park, N.C.) – Wavefront Power’s Very Large Flapper Array (VLFA) is being developed for utility-scale power production from deep water ocean swell waves. The VLFA generally falls into the oscillating wave surge converter category of WEC devices; and
- Waveswing America (Sacramento, Calif.) – The Archimedes Waveswing™ is a submerged point absorber that uses the change in pressure caused by passing waves to expand and contract a large piston. The piston houses a linear generator that converts the relative motion of the two parts directly into electricity.
The two alternate teams are:
- McNatt Ocean Energy (MOE) (Annapolis, Md.) – The MOE WEC is a hinged raft. Wave forcing and the bodies’ dynamic responses leads to a motion about the hinge (called flex), which drives a PTO mechanism that converts the kinetic energy into electricity. It has seven degrees of freedom; and
- Wave Energy Conversion Corporation of America (WECCA) (North Bethesda, Md.) – WECCA’s patent-pending Advanced Wave Energy Conversion System (AWECS) physically presents as three articulating barges, securely anchored offshore, which survived nine years of WEC platform concept testing off the west coast of Ireland.
Testing is scheduled to begin in August and run through mid-October. DOE anticipates announcing the prize winner(s) in November. For more information about the teams, please visit
Alison LaBonte, PhD, is the marine and hydrokinetic technology program manager for the U.S. Department of Energy’s Wind and Water Power Technologies Office.
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