Water Power Peer Review

1. Water Power Peer Review PB150 (Scotland) Dr. Philip R. Hart Ocean Power Technologies 1590 Reed Road, Pennington, NJ 08534 609-730-0400 x263 prh@oceanpowertech.com Sept 27, 2011 Advanced, High Power, Next Scale, Wave Energy Conversion Device

2. Purpose, Objectives, & Integration This project addresses the scaling up of current OPT technology from 150kW to 500kW to advance the project from TRL 3 to TRL 4. • Larger structure size means a reduction in per kW cost, however this comes at the price of higher structural loading. • Higher extraction efficiencies must be obtained. • Installation costs are now a large percentage of overall cost. • At sea maintenance is a focus from the start. Solving the problems above builds a design foundation to allow for a lower cost of energy. • Reduces full lifecycle costing. • Makes use of economies of scale; one installation, one set of maintenance, less infrastructure, per 500kW. The completion of tasks described in this presentation under DOE grant DE-EE0002946 is part of a larger project to advance the design and development of OPT’s next scale 500kW PowerBuoy (PB500). Under DOE grant DE-EE0003645, OPT will conduct further study and design to advance the PB500 development from TRL 4 to TRL 5/6.

3. Technical Approach The technical approach: • Determine three technology solutions for each major subsystems within PB500 Power-Take-Off and Structure and Mooring Systems. • Conduct analysis, testing and generate a scorecard to select final technology solution. • Conduct Conceptual Design study on final subsystem technology solution selected for Power-Take-Off system. • Stage-gated development program with clearly defined stage reviews. • Clearly defined stage deliverables. • Overseen by interdepartmental management and peers prior to proceeding to the next stage (go/no-go decision).

4. Technical Approach Key issues: • Scale-up increases structure loading. • Scale-up places more emphasis on installation costs and maintenance considerations. • Complex systems integration, operations, and control scheme due to scale-up • Design for low-cost, large scale manufacturing and production • Design for ease of deployment, maintenance and retrieval Unique approach: • Highly developed simulations/modeling validated by testing. • Extensive wave tank and ocean testing experience. • Subsystem and component level bench testing and evaluation before final system integration

5. Plan, Schedule, & Budget Schedule • DOE Grant Initiation date: 2/1/2010 • Planned completion date: 1/31/2012 FY 2011 • Stage Gate 3 – Determine PB500 Power-Take-Off Subsystem and System final Technology Concept Solutions. 4/29/2011. (Complete) • Stage Gate 3 - Survival Condition Wave Tank Testing of three Structure/Mooring concepts and three Float shape concepts to determine hydrodynamic loads and select most feasible configuration. 4/29/2011. (Complete) • Stage Gate 3 - Operational Condition Wave Tank Testing of three Structure/Mooring concepts and three Float shape concepts to determine the power output and select the most feasible configuration. 4/29/2011. (Complete) • Stage Gate 3 - PB500 Systems Final Technology Concept Solutions. 4/29/2011. (Complete) • At the end of Stage Gate 3, the final Power-Take-Off and Structural concepts for the PB500 system were reviewed and the design decisions were made:

6. Plan, Schedule, & Budget Schedule • DOE Grant Initiation date: 2/1/2010 • Planned completion date: 1/31/2012 FY 2012 • Stage Gate 4 - Conduct PB500 Power-Take-Off Final Conceptual Design. 10/31/11. (Planned Completion) • Stage Gate 4 - Conduct PB500 Power-Take-Off bench-top testing and scale model testing as required. 1/31/2012. (Planned Completion) • At the end of Stage Gate 4, a Go/No-Go decision will be made after the bench-top test and scale model test results are reviewed. 1/31/2012. (Planned Completion) • If the final conceptual design passes the Stage Gate review, PB500 preliminary design will commence.

7. Plan, Schedule, & Budget Budget: • There were no significant budget variances. • 67% or $1,002,077 out of the total grant amount of $1,500,000 has been expended to date (August 31,2011).

8. Plan, Schedule, & Budget Budget plan for FY12: • OPT does not anticipate significant budget variances for fiscal year 2012. • The spend profile per month for FY12, starting October 1, 2011 through the contract completion date of January 31,2012 is outlined below. • The total planed expenditure for FY10, F11 and FY 12 is outlined below. The total planned expenditure until 1/31/2011 matches the grant amount of $1,500,000.

9. Accomplishments and Results Technical Accomplishments: • Detailed analysis and testing of several Power-Take-Off Mechanisms identified the most efficient mechanism (project milestone). • Analysis and Testing of several Electronic Control and Software schemes identified the most optimal electronic hardware, software and communications configuration (project milestone). • Comprehensive Analysis of several Power Management and Transmission schemes identified the most optimal configuration (project milestone). • Detailed Analysis of several Energy Storage and Transmission schemes identified the most optimal configuration (project milestone). • Wave tank analysis has identified the most efficient float and mooring configuration for energy conversion (project milestone). • Comprehensive geographical analysis for site suitability of competing design concepts. • Component and subsystem testing. • Design concepts developed far enough to allow for technical feasibility, and cost modeling (project milestone).

10. Accomplishments and Results Benchmark against technical targets: • Evaluated a 9 different combinations of mooring systems and float designs • Performed Operational and Survival Wave Tank Testing • Operational Testing measured absorbed power using moving float and functional Power Take Off • Survival Testing measured mechanical loads at key interfaces subject to 100 year storm conditions • Quantified trade-off between mooring systems • Mooring options provide 25% variance in power but have a direct effect on reaction loads. • Selected best Mooring Option • Evaluated three different geometric shapes • Selected float design which provides more energy capture

11. Accomplishments and Results Benchmark against technical targets (cont.): • Power-Take-Off (PTO) Mechanism • Strong modularized PTO system with high power generation efficiency • Great Scalability for PowerBuoys with different power ratings • Enhanced mechanical components reliabilities but with more forgiving and less precision assembly processes • Power Generator • Worked with generator vendors to maximize efficiency around wave power waveforms • Designed to improved generator packaging, alignment and assembly. • Power Management and Conditioning • Standardized AC voltage output to utilize standard COTS devices to reduce component count, cost and complexity. • Design of chosen power inverters increases overall reliability and reduces scheduled maintenance.

12. Accomplishments and Results Benchmark against technical targets (cont.): • Energy Storage • Selected energy storage equipment based on our expected waveform in an effort to minimize cost, and maximize reliability and efficiency. • There is a study ongoing to possibly replace conventional energy storage technology with new technology that provides increased reliability/life. • Communications • Identified modern network equipment and practices to improve reliability and efficiency • Selected Components with high MTBF and low power consumption • Dual-homming scheme adopted for longevity and system level reliability • Further investigating long range communication devices • Electronic Control and Software • Investigated and decided on Networked I/O control scheme that provide the following advantages over Non-Networked I/O. • Less wiring and electrical assembly complexity • Better signal integrity and significant noise immunity • Improved modularity and flexibility • Made available because of new industrial communications protocol

13. Challenges to Date Most important challenges: • Producing scaled-up design concepts that are cost effective in terms of both CAPEX and OPEX. No impact on progress to date. • Increase of power extraction efficiency through implementation of advanced methods, validation of computer models through wave tank testing. No impact on progress to date. Issues or challenges faced: • Very high structural loading was predicted via computer models and verified during wave tank testing. This required careful analysis and implementation of creative design solutions to mitigate these effects.

14. Next Steps Project plans (PB500 Stage Gate 3 under DOE grant DE-EE0002649): Task Name % complete Start Finish PB500 Mooring Load Studies 100 06/7/10 07/30/10 PB500 Float Shape Studies 100 06/21/10 07/30/10 Wave Tank Testing – Operational Cond. 100 08/02/10 11/19/10 Wave Tank Testing – Survival Cond. 100 10/04/10 02/18/11 Mooring/Structure Trade Study Analysis 100 08/02/10 02/25/11 Power-Take-Off (PTO) Mechanism Dev. 100 06/01/10 03/18/11 Power Generator Development 100 08/02/10 03/18/11 Power Management Development 100 08/30/10 03/18/11 Energy Storage Development 100 08/30/10 03/18/11 Communications System Development 100 09/06/10 02/25/11 Electronic Control and Software Dev. 100 08/30/10 03/18/11 Combine Selected Concepts 100 03/21/11 04/22/11 Conduct Stage Gate 3 Review 100 04/25/11 04/29/11

15. Next Steps Project plans (PB500 Stage Gate 4 under DOE grant DE-EE0002649): Task Name % complete Start Finish Generate Stage Gate 4 Project Plan 100 05/02/11 05/06/11 PB500 Stage Gate 4 Project Kick-Off 100 05/09/11 05/09/11 Generate PTO Design Specification 100 05/10/11 05/20/11 Power-Take-Off (PTO) Concept Design 80 05/23/11 09/30/11 Finalize Generator Selection & Procure 50 05/23/11 12/16/11 Finalize Power Management & Procure 50 05/30/11 11/25/11 Finalize Energy Storage & Procure 50 05/30/11 11/25/11 Finalize Comm. System & Procure 40 05/30/11 11/25/11 Finalize Electronic Control & Procure 40 05/30/11 11/25/11 Conduct Bench and Scale Model Test 10 09/6/11 01/31/12 • End of project for DOE grant DE-EE0002649 scheduled for 1/31/2012.

16. Next Steps Next steps: • Plans for expansion and continuation of all work produced in this project are detailed in follow-on DOE grant (DE-EE0003645).