Direct Drive Wave Energy Buoy by hcj


									Water Power Peer Review

                                           Ken Rhinefrank
Direct Drive Wave Energy Buoy
                                           [Columbia Power Technologies, Inc.]
Manta Direct Drive Wave Energy Converter   []
                                           [November 2, 2011]

1 | Program Name or Ancillary Text                                 
Purpose, Objectives, & Integration

                         Challenges-Barriers-Knowledge Gaps
          Wave energy is the only renewable energy source that is not
          commercially installed. Numerous designs and concepts exist
          and most are early stage with limited knowledge concerning
          the actual CoE or ability to operate and survive in this harsh

          Furthermore the systems can be complex in design, non-
          linear in performance and include numerous cost uncertainties
          such as grid integration and permitting. In real sea conditions,
          numerical energy predictions can be off by over 40%. Until
          prototypes are designed built and tested we will not know the
          true cost of energy or be able to reliably forecast methods of
          cost reduction.

2 | Wind and Water Power Program                            
Purpose, Objectives, & Integration

          How Solving Problem Relates to Program Mission
          The design and development of a wave energy system is
          complex and detailed. Only through a staged project
          development approach, where actual performance and
          operation are measured and observed experimentally at
          a sufficiently large scale and where complete system
          designs are developed, built and tested, can the actual
          cost of energy can be assessed.

3 | Wind and Water Power Program                   
Purpose, Objectives, & Integration

                        Integration of this Project
          Results from this project are used to inform the utility-
          scale design process, improve cost estimates, accurately
          forecast energy production and to observe system
          operation and survivability. Knowledge and experience
          gained from this project is applied to major program
          objectives including:
     •    Design and certification of the commercial-scale system
     •    Land-based test of a commercial-scale generator, bearing and seals
     •    Open-ocean deployment of a commercial-scale DDR WEC in
          conjunction with a recognized independent testing center.

4 | Wind and Water Power Program                              
Technical Approach

                            Project Approach
          The primary goal of this project is an intermediate-scale
          (1:7) bay/ocean test of a novel Direct-Drive Rotary Wave
          Energy Converter (DDR WEC). Key tasks include:
     •    WEC Optimization
            – Shape, CG, inertial using AQWA and Wave Dyne numerical models
            – PTO Controls Optimization
     •    33rd scale tank testing, performance and survival analysis
     •    7th scale testing at sea (design, build, deployment and experiments)
     •    Data analysis of 7th scale results
     •    Integration of findings into Commercial Scale Design

5 | Wind and Water Power Program                                    
Technical Approach

  • WEC body optimization complete
         •    AQWA numerical optimization
         •    Over 368 unique shape simulations
         •    311 unique CG and inertia simulations
         •    1700+ hours of computer simulation time
         •    “Gen 3.1” 230% energy capture improvement versus
              “Gen 3 “ 15th scale
         •    PTO Controls Optimization
         •    Ballast Optimization
         •    Interim Optimization Report complete

6 | Wind and Water Power Program                       
Technical Approach

     •    33rd scale tank testing and performance analysis complete
            •   Design & Fabrication complete
            •   Testing services and test plan contracted and completed
            •   Regular waves, irregular waves, 50 year and 100 year storm waves
            •   Wave data has been analyzed
            •   Performance measures and RAO’s assessed
            •   Numerical and experimental comparisons in progress, example RAO below

7 | Wind and Water Power Program                                              
Technical Approach

     •    7th scale Testing at sea (design, fabrication, ops. and experiment)
                                   SEA TRIAL UNDERWAY



8 | Wind and Water Power Program                                    
Technical Approach

      • Data Analysis
             • Data Collection and Deployment ongoing
                     Ø Wave occurrence is ~40% of the time in winter
                     Ø Remote WEC data collection through 3G network
                     Ø AWAC data collection through periodic site visits
                     Ø 7-24 surveillance camera
                     Ø Solar power small waves in summer
                     Ø Periodic service visits
                     Ø Periodic battery charges
             • Analysis Methodology is developed
                     Ø Third-party review of approach ongoing
                     Ø Statistical characterization of waves
                     Ø Assessment of data quality
      • Integrate Findings into Commercial Scale Design
             • Design in progress
9 | Wind and Water Power Program                                 
Plan, Schedule, & Budget

     • Initiation date: December 1, 2009
     • Planned completion date: March 26, 2011
         – Deployment extended beyond May 2011 by up to nine months to collect
             more data
     • Milestones
         Ö WEC Optimization
         Ö 33rd scale wave tank experiment
         Ö 7th scale design
         Ö Permits approved
         Ö 7th scale fabrication complete
         Ö Deployment Underway
         q WEC Recovery
         q Data Analysis
         q Commercial design integration
10 | Wind and Water Power Program                                  
Plan, Schedule, & Budget

     •    Go/no-go decision points
           – Performance and cost assessment
           – Utility scale prototype site selection
           – Project funding availability for major tasks:
               • PTO test
               • Commercial scale build and deployment

     • Remaining budget will be utilized during remainder of deployment period
     • 71% of budget utilized to date.
                                            Budget History
                     FY2009                        FY2010                        FY2011

            DOE               Cost-share   DOE              Cost-share   DOE              Cost-share

              0                     0      $573K              $573K      $601K              $601K

11 | Wind and Water Power Program                                                         
Accomplishments and Results

     • 230% increase in energy capture

     • Successful Design/Fabrication, Puget Sound-Deployment
          Knowledge gained through the design, fabrication, test and
          deployment of a 7 ton intermediate scale WEC is extensive and has
          proven to be an essential and valuable stage in our technology
          readiness level.

     • Continued operation at sea for over eight months
          This milestone is demonstrating a viable technology for extracting
          energy from ocean waves and provides confidence in our design as
          we move toward an open-ocean utility-scale demonstration.
          Preliminary indications of energy generation are on track with
          numerical estimates.

12 | Wind and Water Power Program                              
Challenges to Date

     Prototype Power draw very high
     • Active/Standby design load 60/40 W, design creep and deviation from spec ->105W
     • 105W = 95 kW full scale equivalent -> “Instrumentation does not scale down well”
     • Original charge frequency 20 to 25 days with average WEC shaft power of 45W
     • Deployment extension into summer months (less wave energy)
     • Power electronics failure

     • $3k battery charges at 2x per week
     • Installation of Solar panels kept electronics working all summer without charges
     • Upgrades to wave energy power electronics
     • Future systems installed in small scale wave climates need more storage and backup
        energy sources.

13 | Wind and Water Power Program                                         
Challenges to Date

     DDR voltage and power variance and high demand on
       electronics eventually caused failure
     • Cyclic speed and voltage with average levels an order of magnitude lower than peak.
     • Possible damage due to thermal overload
     • No commercially viable solution that fit the prototype needs requiring a custom
        solution at this scale.
     • Accelerated design path to meet schedule

     • Original design and backup designs planned for this failure and applied linear
        damping controls even in failed conditions which allowed for continued collection of
        performance data.
     • Redesigned and repaired power electronics.
     • Commercial design includes cost tradeoffs between voltage peak reduction and over-
        specified power electronics.
     • Post deployment autopsy to find possible cause
14 | Wind and Water Power Program                                            
Challenges to Date

     Wave data analysis at 1:7 scale is difficult in ocean setting
     • Relatively deep water (22m) decreased high frequency response of AWAC
     • 7th scale spectrum is at the high frequency limit of commercially available and
        deployable wave monitoring instruments that were practical at this location.
     • Regionally available intermediate scaled (1:4 to 1:10) wave climates do not support
        larger than 1:7 scale tests.
     • Lager scales too expensive to test for this level of readiness.

     • Accept imperfection while assuring data is sufficient (marginally met at Nyquist rate)
     • Mount AWAC on a mid column buoy to increase frequency response.
     • Monitor data from AWAC through acoustic modem to WEC and then to shore
     • Post process time series data into spectral format using in-house code

15 | Wind and Water Power Program                                              
Challenges to Date

     Evaluating 1:7 scale wave data
        Regions where shipping traffic produces relatively large waves introduce post
        processing requirements not normally associated with tank testing or utility scale
        ocean testing scenarios.
     • Creative post processing

     Data collection requirements (frequency and quantity)
          Prototype test requirements exceed those expected for a final utility application. Data
          collection and storage for prototype testing requires very high reliability.

     • Not satisfied with dSpace/PC based solution used this time, alternatives are under

16 | Wind and Water Power Program                                                  
Next Steps

            Ø Continue deployed testing & determine when data is sufficient
            Daily monitoring, post processing, WEC battery charges, AWAC servicing

            Ø WEC Recovery
            Remove all equipment

            Ø Data Analysis

            Ø Commercial design integration

            Ø Final report

17 | Wind and Water Power Program                                          

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