WAVE ENERGY TESTING USING THE OCEAN SENTINEL INSTRUMENTATION BUOY

Transcription

1 Proceedings of the st Marine Energy Technology Symposium METS3 April 0-, 203, Washington, D.C. WAVE ENERGY TESTING USING THE OCEAN SENTINEL INSTRUMENTATION BUOY Annette von Jouanne Oregon State University Corvallis, OR, USA Terry Lettenmaier Oregon State University Corvallis, OR, USA Ean Amon Oregon State University Corvallis, OR, USA Sean Moran Oregon State University Corvallis, OR, USA Corresponding author: ABSTRACT The Ocean Sentinel instrumentation buoy was developed by the Northwest National Marine Renewable Energy Center (NNMREC) in collaboration with AXYS Technologies for the testing of wave energy converters (WECs). NNMREC is a Department of Energy sponsored partnership between Oregon State University (OSU) and the University of Washington (UW). The Ocean Sentinel instrumentation buoy is a surface buoy based on the 6-meter NOMAD (Navy Oceanographic Meteorological Automatic Device) design, and provides power analysis and data acquisition, environmental monitoring, as well as an active converter interface to control power dissipation to an on-board electrical load. The Ocean Sentinel was first deployed in August 202 for the testing of a half-scale WEC, the WET-NZ device, which is the acronym for Wave Energy Technology-New Zealand. The WEC and the Ocean Sentinel were moored at NNMREC s openocean test site north of Newport, OR for a sixweek period while the testing was performed. This paper presents the Ocean Sentinel instrumentation buoy platform, and the 202 deployment with the WET-NZ. INTRODUCTION An extremely abundant and promising source of energy exists in the world s oceans. Ocean energy exists in the forms of wave, tidal, marine currents, thermal (temperature gradient) and salinity. Among these energy forms, significant opportunities and benefits have been identified in the area of ocean wave energy extraction, i.e., harnessing the motion of the ocean waves, and converting that motion into electrical energy. When compared to other renewable energy resources such as wind and solar, ocean waves offer several attractive qualities including high power density, low variability and excellent forecastability. Ocean wave energy is an area of increased interest, with a number of wave energy converter (WEC) prototypes being developed around the world. Ocean testing facilities are essential to enable wave energy developers to demonstrate performance and survivability, and to optimize devices. Many WEC technologies are ready for field trials, but are not sufficiently mature to be connected to the electrical grid for commercial power production. This paper presents the Ocean Sentinel instrumentation buoy solution that has been developed by the Northwest National Marine Renewable Energy Center (NNMREC) in collaboration with AXYS Technologies for the nongrid-connected testing of WECs. The Ocean Sentinel was completed in 202, and was first deployed to test an experimental half-scale Wave Energy Technology New Zealand (WET-NZ) WEC for a six-week period during the months of August through October 202. The Ocean Sentinel and WET-NZ were moored at a permitted Pacific Ocean test site that NNMREC has established off the coast of Newport, Oregon. The operation of both the WET-NZ and Ocean Sentinel were successfully demonstrated during this deployment.

2 FIGURE. NNMREC WAVE ENERGY TESTING ASSETS. THE NORTHWEST NATIONAL MARINE RENEWABLE ENERGY CENTER (NNMREC) Since 2004, Oregon State University (OSU) has made significant advancements in marine renewables including the establishment of a National Marine Renewable Energy Center in Oregon, which was awarded by the U.S. Department of Energy in September 2008 through the Water Power Program. NNMREC is headquartered at OSU, and is a partnership between OSU and the University of Washington (UW). NNMREC s mission is to facilitate the commercialization of marine energy technology, inform regulatory and policy decisions, and to close key gaps in scientific understanding with a focus on student growth and development. Primary center activities include: ) development of facilities to serve as an integrated, standardized test center for U.S. and international developers of wave and tidal energy; 2) evaluation of potential environmental, ecological and social impacts, focusing on the compatibility of marine energy technologies in areas with sensitive environments and existing users; 3) device and array optimization for effective deployment of wave and tidal energy technologies; and 4) increasing reliability and survivability of marine energy systems. Figure summarizes the NNMREC wave energy assets for testing small-scale to utilityscale devices, including all phases of technology development. NNMREC s wave energy ocean testing facilities are being developed in a multistep process where the first step consists of scaled (up to 00 kw average power) mobile ocean test berths including power analysis & data acquisition systems and load banks for power dissipation, where the Ocean Sentinel represents the stand alone instrumentation buoy platform. The next steps include the development of a utility-scale Pacific Marine Energy Center (PMEC); see Figure 2, which will be the first utility scale, gridconnected wave energy test site in the United States. PMEC plans include four test berths (current plan is for four separate cables), approximately five miles from shore capable of testing individual WECs or arrays of WEC devices. FIGURE 2. PROPOSED PACIFIC MARINE ENERGY CENTER (PMEC). 2

3 Approximately 25 m THE OCEAN SENTINEL INSTRUMENTATION BUOY A novel Ocean Sentinel instrumentation buoy has been developed by NNMREC and AXYS Technologies for WEC testing []. The Ocean Sentinel is shown on station in Figure 3, and a conceptual diagram of the Ocean Sentinel testing a WEC is shown in Figure 4. The Ocean Sentinel is a surface buoy, based on the 6-meter NOMAD (Navy Oceanographic Meteorological Automatic Device) buoy design. This instrumentation buoy facilitates open-ocean, stand-alone testing of WECs with average power outputs of up to 00 kw. Deployment is typically at the NNMREC openocean test site, which is approximately 2.5 nautical miles offshore from Yaquina Head, north of Newport, Oregon. WECs under test are moored approximately 25 meters from the instrumentation buoy and connected by a power and communications umbilical cable. Power generated by the WEC is controlled by switchgear and power conversion equipment located on board the instrumentation buoy and dissipated in an onboard load bank. Wave data recorded by a nearby TRIAXYS wave measuring buoy is also transmitted to the Ocean Sentinel, via wireless telemetry. FIGURE 3. OCEAN SENTINEL INSTRUMENTATION BUOY ON STATION. The primary functions of the Ocean Sentinel instrumentation buoy are as follows:. Provide stand-alone electrical loading and power conversion for the WEC under test. 2. Measure and record WEC power output. 3. Collect and store data transmitted from the TRIAXYS wave measuring buoy moored nearby. 4. Conduct environmental monitoring via onboard instrumentation. 5. Transmit collected data to a shore station via a wireless telemetry system. TRIAXYS Wave Measuring Buoy WEC Under Test To shore Ocean Sentinel Instrumentation Buoy Load bank DAS & Telemetry Power Conversion Umbilical FIGURE 4. WEC TESTING WITH THE OCEAN SENTINEL INSTRUMENTATION BUOY. 3

4 WEC electrical loading, power conversion, and CompactRIO data acquisition The WEC electrical loading, power conversion, and data acquisition system on the Ocean Sentinel, for the testing of WECs, was developed by NNMREC. This system, shown in Figure 5, interfaces WEC electrical generators to the Ocean Sentinel load banks and records measured data including the WEC power output and ocean wave data. The design was based on an earlier NNMREC design used to test small scale WECs from a support vessel [2]. Generator control is provided for WECs in early stages of development that do not include onboard generator power conversion. This system consists of the following equipment:. Air cooled resistive load banks that dissipate the power generated by the WEC being tested. 2. Electrical switchgear that includes a disconnect and fuses, contactors for direct switching of the load banks, contactors and soft start circuitry for a power converter, and voltage and current transducers to measure the output power of the WEC being tested. 3. A power electronic converter that can provide a continuously adjustable load to the generator of the WEC being tested. 4. A National Instruments (NI) CompactRIO data acquisition and control system that controls the switchgear contactors and the power electronic converter, and records electrical data from the switchgear and converter, the output power of the WEC being tested, and ocean wave and ocean current data from the TRIAXYS wave buoy. The CompactRIO data acquisition and control includes a host PC on shore which communicates via wireless telemetry with the Ocean Sentinel and provides the user interface for controlling and monitoring WEC operation during tests. The CompactRIO system is programmed using NI LabVIEW software and is an off-the-shelf system that can be reconfigured for the requirements of different WECs being tested with the Ocean Sentinel. Because NNMREC anticipates testing WECs with different power outputs and generator configurations, the Ocean Sentinel loading system has been designed for a high degree of flexibility and is reconfigurable via terminations in the switchgear enclosure. The air cooled load banks can be reconnected for different voltage and power levels, and can be controlled by either contactor switching, converter control, or a combination of the two. WECs with output current up to 25 A continuous can be accommodated, for a power capability of 00 kw at 460 V or 50 kw at 230 V. WEC Generator 3Ø Umbilical Disconnect Switchgear Load Banks 3Ø 25 kw 3Ø 25 kw 50 kw V Sense Soft start Host PC TRIAXYS Wave buoy GPS 900 MHz Watchman 500 3G cell modem DAS & Telemetry 3Ø Iac 3Ø Vac Ethernet Serial NI 9205 NI 9205 NI 9267 NI 9474 crio-94 FPGA crio-9025 controller EtherCAT Passive rectifier Converter V, I, T sensors Gate drive NI-944 EtherCAT FIGURE 5. THE WEC ELECTRICAL LOADING, POWER CONVERSION, AND DATA ACQUISITION SYSTEM ON THE OCEAN SENTINEL. 3Ø Idc + Vdc - slave FPGA NI 9205 NI 940 NI 9474 To coolant pump 4

5 Instrumentation Power System The Ocean Sentinel includes an instrumentation power system developed by AXYS Technologies, which can supply up to 400W of power at 24 Vdc and 20 Vac to the instrumentation and power conversion equipment installed on the Ocean Sentinel, and to the WEC via the umbilical cable. 250 W is budgeted for on board power consumption, leaving 50 W for export to the WEC being tested. A diagram of this system is shown in Figure 6. Primary power is provided by 40 sealed lead acid batteries (2000 Amp-hours at 24V), which are maintained through the use of a kw wind generator, two 20 W solar panels and a 3.2 kw standby diesel generator. The system is capable of providing 400 W continuously throughout a 3 month deployment period without refueling. TRIAXYS Directional Wave Measurement Buoy A TRIAXYS wave buoy procured from AXYS Technologies, shown in Figure 7, is used for ocean wave and current measurements. This buoy is moored approximately 00 m from the WEC under test, and transmits wave and current data to the Ocean Sentinel via radio telemetry. Accelerometer and rate gyro data is processed on board the TRIAXYS buoy to produce both directional and non-directional wave frequency spectra. An Acoustic Doppler Current Profiler (ADCP) on board the TRIAXYS buoy measures the ocean current profile down to a depth of 40 m. The wave frequency spectra and current profile data are transmitted to the Ocean Sentinel, at configurable intervals. FIGURE 6. OCEAN SENTINEL POWER SYSTEM. Watchman 500 Control and Data Acquisition A Watchman 500 control and data acquisition system, developed by AXYS Technologies, controls the instrumentation power system and also provides the following functions on the Ocean Sentinel:. Provides safety functions including bilge level and mooring watch circle monitoring. 2. Interfaces with an Automatic Identification System (AIS). 3. Interfaces with the TRIAXYS wave measuring buoy to receive ocean wave and current data. 4. Interfaces with onboard environmental sensors and video cameras. 5. Records power system, wind, ocean current, and ocean wave data. 6. Sends ocean wave, ocean current, temperature and wind data to the CompactRIO DAS through a serial link. In addition, the Watchman 500 has the capability to record data from instrumentation installed on the Ocean Sentinel in the future, including for purposes other than WEC testing. FIGURE 7. TRIAXYS WAVE BUOY. Umbilical Cable The umbilical cable connecting the Ocean Sentinel and the WEC under test is approximately 200 m long. Two alternate umbilical systems can be deployed with the Ocean Sentinel; a high power umbilical with power conductors sized for 25 amps continuous, and a low power umbilical with power conductors sized for 40 amps continuous. The power conductor insulation is rated for 000 volts in both umbilicals. The conductors that are included in each umbilical are listed in Table. The heavier, high power umbilical requires specialized cable machinery on board a large vessel for deployment so will only be used for higher power WECs. The low power umbilical was developed specifically for the 202 WET-NZ tests, and is light enough to be deployed by hand from a small boat. The present low power umbilical does not include fiber optics for communication between the WEC and Ocean Sentinel, however, a different low power umbilical with communication capability will be procured as needed for future deployments. 5

6 TABLE. CONDUCTORS FOR HIGH AND LOW POWER UMBILICAL CABLES. Low Power High Power Conductors umbilical umbilical WEC output power and ground WEC auxiliary power, neutral sense, or other Fiber optic (4) 6 AWG (2) 6 AWG None (5) 6 AWG (3) 6 AWG (4) pairs Single mode Telemetry Systems Two independent cellular telemetry systems are used between the Ocean Sentinel and shore, one for the Watchman 500 system, and the other for the CompactRIO system. There is also a separate cellular link to the TRIAXYS buoy. A 900 MHz serial link is used for communication between the TRIAXYS wave measuring buoy and the Watchman 500 DAS on board the Ocean Sentinel. The Watchman 500 DAS also has an independent INMARSAT D+ satellite communication link providing secondary data transmission and system control capabilities when required. THE WAVE ENERGY TECHNOLOGY NEW ZEALAND (WET-NZ) WAVE ENERGY CONVERTER The WET-NZ wave energy converter is the product of a research consortium between Callaghan Innovation, a New Zealand Crown Entity, and Power Projects Limited (PPL), a Wellington, New Zealand private company. The Oregon deployment was project managed by Northwest Energy Innovations (NWEI), a Portland, OR firm. A photo of the half-scale WET- NZ at sea with the Ocean Sentinel in the background is shown in Figure 8, together with a solid model rendering of the device. Characteristics of the device are listed in Table 2. The device tested in 202 was half-scale by length; output power scaling per the Froude similitude criteria was / relative to a nominal full scale device [3]. The WET-NZ consists of a long submerged hull, with a Power Pod mounted on top which includes a cylindrical float and the power take-off system. The hull of the half-scale WET-NZ tested with the Ocean Sentinel was fabricated at Oregon Iron Works in Portland, OR, while the float and Power Pod were fabricated and assembled in New Zealand. The hull, float and Power Pod were assembled at the Port of Toledo Boat Yard near Newport, OR, before deployment. The float of the WET-NZ is coupled through its shaft to the power-take-off (PTO) system and rotates up and down in the waves to generate power. The WET-NZ is designed to be slackmoored and self-reacting; the hull is flooded with seawater to give it a large inertia for the float to react against [4]. The natural period of the halfscale WET-NZ spar, which consists of the entire device other than the float, is 5 seconds, and the natural period of the half-scale float is 3.5 seconds. Due to these natural periods, Callaghan Innovation simulations predicted that the half-scale device would not generate significant power for portions of the wave spectra with periods longer than approximately 9 seconds. A full-scale WET-NZ device, however, is expected to have longer natural periods and is projected to operate across the full wave spectra present in the open ocean. Power Pod pod Float Hull FIGURE 8. THE HALF-SCALE WET-NZ WAVE ENERGY CONVERTER. TABLE 2. HALF-SCALE WET-NZ DEVICE CHARACTERISTICS. Length scaling ratio* /2 Power scaling ratio (Froude)* / Peak power 20 kw Draft 5 m Spar natural period 5 s Float natural period 3.5 s *Relative to full-scale device The PTO system for the WET-NZ is shown in Figure 9. A crankshaft that connects to the shaft of the float extends and retracts hydraulic cylinders. The hydraulic cylinders provide pressure to a hydraulic system that includes a hydraulic motor and a small accumulator. The hydraulic motor drives the permanent magnet generator that was 6

7 controlled by the Ocean Sentinel power converter during the test. The hydraulic drive is configured such that the generator only rotates in one direction. An accumulator provides a selected amount of energy storage within the hydraulic system, so that the generator speed and torque do not necessarily decrease to zero when the shaft of the float reverses direction twice per ocean wave cycle. Hydraulic cylinder Crankshaft area were marked by corner marker buoys, per US Coast Guard requirements. Ocean swell is typically from the west-northwest at the test site in August and September, with winds typically from the northwest. Test Site Pacific Ocean Yaquina Head Newport, OR Float center of rotation FIGURE 9. THE WET-NZ PTO SYSTEM TESTING OF THE WET-NZ WITH THE OCEAN SENTINEL The WET-NZ and the Ocean Sentinel were deployed at the NNMREC test site that is approximately 2.5 nautical miles offshore from Yaquina Head, north of Newport, Oregon (see Figure 0). The two were deployed from August 22, 202 until October 5, 202 while tests were performed on the WET-NZ. The deployment had a number of objectives, as follows:. To demonstrate and characterize the performance of the WET-NZ concept at half scale. 2. To demonstrate operation of the Ocean Sentinel, and to gain experience testing a WEC with the Ocean Sentinel. 3. To gain experience deploying both the Ocean Sentinel and a WEC in the ocean. 4. To perform environmental monitoring during ocean testing of a WEC. Test Site Layout The layout of the Ocean Sentinel, TRIAXYS wave buoy, and half-scale WET-NZ at the NNMREC test site during the 202 deployment are shown in Figure. Three-point mooring systems were used for both the WET-NZ and Ocean Sentinel. The TRIAXYS wave buoy was moored to the north side of the test site where it was more protected from recreational and fishing vessel traffic. The four corners of the 350 meter by 250 meter test FIGURE 0. THE NNMREC TEST SITE LOCATION. N WET-NZ 350 m Umbilical TRIAXYS Mooring lines Ocean Sentinel Anchors FIGURE. TEST SITE LAYOUT USED FOR THE 202 WET-NZ TESTS. Test Methodology Most of the deployment period was spent characterizing the WET-NZ performance with constant resistance loads applied to the electrical generator. This was the default operating condition when other tests were not being conducted. Much smaller portions of the deployment period were dedicated to experimenting with several different adaptive control methods. Survivability tests with no electrical load applied to the WET-NZ generator were also conducted, during the most severe sea conditions encountered during the deployment. During the constant resistance load tests, different constant resistive loads were applied to the WET-NZ generator for fixed time periods over a wide range of sea conditions, while WEC output power was measured. During these tests, the 250 m 7

8 WET-NZ generator was loaded by the Ocean Sentinel power converter shown in Figure 5, with the power converter control configured so that generator output current was proportional to generator output voltage to represent a constant resistance load. The power converter provided a continuous selection of load resistances, which was not possible with contactor control of the load banks. The constant resistance loading provided an approximation to constant damping control of the WEC float, where the force applied to the float is kept proportional to the speed of the float, assuming that float force was proportional to generator torque and float speed was proportional to generator speed. Generator torque is proportional to current, and generator speed is proportional to voltage. In the case of the WET-NZ, the PTO hydraulics and the rotating float create non-linearities between float and generator speed, and also between the float force and generator torque, so that fixed resistance control only approximates constant damping control. Testing was performed with constant resistance control because it was simple to implement. Although PTO non-linearities and losses were expected to have some effect, results were still expected to be consistent with analysis of the WEC that assumed constant damping. During initial testing, a load cycling method was developed where the Ocean Sentinel CompactRIO host was programmed to cycle repeatedly through a sequence of different resistance settings every 20 minutes. This proved to be an effective method of collecting data with different loads applied under similar sea conditions. The 20 minute period for each load step was synchronized with the 20 minute measurement period of the TRIAXYS wave buoy. This load cycling method was used for the remainder of the test and is illustrated in Figure 3, which shows plots of time series data recorded during a short segment of the test. The upper plots show the average power recorded for each 20 minute interval together with the resistance setting for that interval. Power is represented as the percent of the maximum recorded during the deployment period to protect proprietary WET- NZ data. The lower plots show the significant wave height (H m0) and energy periods (T e) recorded by the TRIAXYS wave buoy for each 20 minute period. Similar data plots were used to assess performance during the course of the test. In the example shown in Figure 3, output power is usually higher at the intermediate resistance settings than the extreme settings. A similar load cycling method was used to alternate between control settings while experimenting with different adaptive control methods. Resistance (Ohms) Hm0 (m) Resistance cycled between Ohms 40 8% 20 Rdc 6% % Power 4% 00 2% 80 0% 60 8% 40 6% 4% 20 2% 0 0% 9/4 6:00 9/4 8:24 9/4 0:48 9/4 3:2 9/4 5:36 Date - Time (UTC) Hm0 Te 0.6 9/4 6:00 9/4 7:26 9/4 8:52 9/4 0:9 9/4 :45 9/4 3:2 9/4 4:38 Date - Time (UTC) FIGURE 3. SAMPLE TIME SERIES DATA FOR WET- NZ CONSTANT LOAD RESISTANCE TESTS. Sea Conditions A large set of 20 minute data samples was collected during the deployment for constant resistance operation under a variety of sea conditions. A histogram of the 20 minute sample counts for each one-half meter wide H m0 and one second wide T e bin is shown in Figure 4 that includes data for all resistance settings used. H m0 and T e are calculated from zero and first negative moments (m 0 and m -) of the wave spectra recorded by the TRIAXYS wave buoy, per equations () and (2). Hm0 Bin Center (m) H m0 = 4 m 0 () T e = m m 0 (2) Sample Count (20 min sample periods) Aug 27 - Oct 5, constant Rdc operating data FIGURE 4. HISTOGRAM OF SAMPLE COUNTS FOR CONSTANT LOAD RESISTANCE DATA Te Bin Center (s) Power (% of deployment maximum) Te (s) 8

9 The half-scale WET-NZ device was not expected to produce significant power from portions of the wave spectra with periods greater than approximately 9 seconds. More test time was therefore desired in conditions with lower Te, especially in the 6 to 8 second range, than occurred during the deployment. Much of the testing was carried out in longer period seas, where the WET-NZ responded more to the shorter wind waves in the spectra than to the ocean swell. Results After the deployment period, data collected on board the Ocean Sentinel was analyzed by NNMREC. Most of the analysis focused on characterizing the WET-NZ performance while constant resistance loads were applied under different sea conditions. Data included average power, load resistance, and both ocean wave statistics and spectra for each 20 minute sample period. Data collected while the WET-NZ was controlled using other methods was also assessed. Callaghan Innovation independently analyzed data that was collected on board the WET-NZ using a separate data acquisition system. Some of the results of the half-scale WET-NZ tests were as follows:. An optimum in the device power output with respect to the constant resistance load applied to the generator was observed and characterized. 2. The low response of the half-scale WET-NZ to wave periods greater than 9 seconds that was predicted by Callaghan Innovation simulations was verified. 3. Controlled external resistance loading via the Ocean Sentinel allowed essential data to be collected on board the WET-NZ, from which the PTO operation was characterized in detail by Callaghan Innovation under a wide range of sea conditions. 4. The CompactRIO control on the Ocean Sentinel was effectively used to experiment with different adaptive control methods. Some of these methods have potential to improve WEC output power, although insufficient data was collected to fully characterize device performance 5. No issues were observed during no-load survivability testing of the WET-NZ, carried out under the most severe sea conditions that occurred during the deployment. All systems on the Ocean Sentinel performed flawlessly during its first deployment and it proved to be a very effective platform for performing the open ocean WEC tests. CONCLUSIONS NNMREC developed the Ocean Sentinel instrumentation buoy to establish wave energy ocean testing facilities. The Ocean Sentinel, completed in 202, facilitates open ocean, standalone testing for scaled WECs up to 00 kw average power, and is able to provide WEC generator control for WECs that do not include onboard generator power conversion. The Ocean Sentinel is typically deployed at the permitted NNMREC test site near Newport, OR. The Ocean Sentinel was deployed for the first time to test the half-scale WET-NZ wave energy converter for a six-week period in August- October, 202. Because the half-scale WET-NZ model does not include its own generator control, the power converter on board the Ocean Sentinel provided this function during the tests. The Ocean Sentinel performed superbly throughout its first deployment, and the ability of the power converter together with the CompactRIO control and data acquisition to control the WET-NZ generator load and collect data proved to be very effective for evaluating WEC performance. A method of using the CompactRIO host to cycle between alternate control settings in synchronism with the TRIAXYS measurement period was developed early in the test that was particularly useful for collecting the half-scale device characterization data. Due to Froude scaling, the open ocean seas generally had longer periods than desired for halfscale WET-NZ model testing during the deployment. Although more test time was desired in conditions with shorter wave periods, essential data was collected during the deployment period to characterize the output power of the device as well as PTO operation while operating under a range of constant resistance loads. The CompactRIO control of the power converter on the Ocean Sentinel was effectively used to experiment with several different adaptive control techniques applied to the WET-NZ. The ability of the halfscale WET-NZ to survive severe sea conditions under no load was also demonstrated during the deployment. ACKNOWLEDGEMENTS The authors acknowledge support for this work from the US Department of Energy (Award Number DE-FG36-08GO879) for the Northwest National Marine Renewable Energy Center (NNMREC), and the State of Oregon Capital Funding Program. The support of the following agencies has been a tremendous benefit to OSU s wave energy research: the Oregon delegation, Bonneville Power Administration (BPA), Central 9

10 Lincoln PUD (CLPUD), Portland General Electric (PGE), Pacific Power, Oregon Sea Grant (OSG), and the Fishermen Involved in Natural Energy (FINE). NNMREC gratefully acknowledges the excellent collaboration in testing the WET-NZ, whose deployment team was led by Callaghan Innovation and Northwest Energy Innovations (NWEI), and with NREL for their participation in test planning and deployment preparation. The authors and WET-NZ would like to thank the New Zealand Ministry of Business Innovation and Employment (formerly the Foundation for Research, Science and Technology), the Energy Efficiency and Conservation Authority (EECA), and the Oregon Wave Energy Trust (OWET). REFERENCES [] A. von Jouanne, T. Lettenmaier, E. A. Amon, T. K. A. Brekken, and R. Phillips, A Novel Ocean Sentinel Instrumentation Buoy for Wave Energy Testing, Marine Technology Society Journal, vol. 47, no., pp [2] E. Amon, T. K. A. Brekken, and A. von Jouanne, A power analysis and data acquisition system for ocean wave energy device testing, Renewable Energy, vol. 36, no. 7, pp , Jul. 20. [3] B. Holmes, Tank testing of wave energy conversion systems: marine renewable energy guides. Orkney: European Marine Energy Centre, [4] L. Le-Ngoc, A. I. Gardiner, R. J. Stuart, A. J. Caughley, and J. A. Huckerby, Progress in the development of a multi-mode self-reacting wave energy converter, in OCEANS 200 IEEE - Sydney, 200, pp. 7. 0