1 | program name or ancillary texteere.energy.gov water power peer review ocgen™ module mooring...

1 | Program Name or Ancillary Text eere.energy.gov

Water Power Peer Review

OCGen™ Module Mooring Project Jarlath McEntee

Ocean Renewable Power [email protected] 1-3, 2011

2 | Wind and Water Power Program eere.energy.gov

Purpose, Objectives, & Integration

Challenges• At present deploying, mooring and retrieval in fast moving water requires specialized equipment

and expertise

• Expensive and limited equipment

• Project aims to define loadings on moored hydrokinetic structures, to develop innovative mooring systems, and to reduce cost associated with installation and retrieval

Program’s mission and objectives• Better understanding of design issues

• Reduced cost and improved reliability

• Reduces LCOE

• Transferrable to other Marine Renewable systems

How This Project will be Integrated• Mooring system design integrated into ORPC’s OCGen™ Power System projects for Maine and

Alaska (Prototypes deployed 2013)


Technical Approach

• Identify the loads acting on the mooring system• Steady fluid loads• Dynamic fluid loads• Dynamic inertial loads

• Scale model testing• Collect geophysical and geotechnical data• Design, build and deploy field size module

• Design of OCGen™ sub-module• Design of mooring system• Deployment and monitoring of system

• Design, build and acquire mooring system for full OCGen™ Power System


Quantify Loads on Mooring

• RANS CFD (Flow 3D)• Provides steady state

lift and drag behavior• Computationally

intense



• Dynamic analysis of tethered systems• University of Washington (NNMREC)

0 1 2 3 4 5 6 7 80

1

2

3

4

5

6

X (m)

Z (

m)

Analytical

Numerical



• ORCAFlex


ORCAFlex Inputs



• Scale model testing


Plan, Schedule, & Budget

Schedule• Initiation date: March 1, 2010• Planned completion date: August 8, 2013

– This reflects an 18-month extension request due to NEPA review delay, which resulted in a schedule and space conflict requiring the relocation of the Mooring Project to an adjacent area in Cobscook Bay, Maine.

• Milestones for FY 10 and FY11– Task 1: Load Modeling– Task 2: Dynamic Stability– Task 3: Dynamic Analysis of Mooring System– Task 4: Scale Model Testing– Task 5: Geophysical Surveys (through 03/06/2012)

• Go/no-go decision points for FY12 and FY13: None to date

Budget: • No budget variances to date.• Portion of the project budget expended to date: $276,123.78

Budget History

FY2009 FY2010 FY2011

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

$0 $0 $222,274.25 $0 $53,849.53 $0


Accomplishments and Results

• Successfully utilized a commercially available CFD code to predict fluid induced loads on the OCGen™ module– Modular, scalable modeling technique

• Developed an analytical tool to predict the dynamic behavior of a tethered floating system in transient flows

• Identified limitations with a commercially available mooring design code and found path to address these

• Performed preliminary scale model tests • Now gathering the required geophysical information for

the proposed field test site, and beginning the design process for the field test module


Accomplishments and Results

Milestone Completion Date

1 Load modeling July 2011

2 Dynamic Stability July 2011

3 Dynamic analysis of Mooring System July 2011

4 Scale Model Testing July 2011

5 Geophysical Surveys March 2012

6 Cable & anchor design September 2012

7 Mooring experiment October 2012

8 Design of OCGen™ Mooring System August 2013

9 Reporting September 2013


Challenges to Date

• Understanding and providing accurate inputs for the ORCAFlex code (apparent mass, etc)– Investigating other analysis codes

• Collecting adequate geophysical and geotechnical site data at a reasonable cost– Working with universities and contractors to improve our

interpretation skills and to identify improved means of site investigation (CPTu, etc)

• Project received NEPA categorical exemption 14 months after project start date. – Rescheduled project activities


Next Steps

• Completion of Analysis for OCGen™ sub-module• Design of cable and mooring system for sub-module• Field deploy, test and monitor a sub-module for 3

months (starting June 2012)• Design of a full scale mooring system for the OCGen™

power system (Fall 2012)• Procurement and installation of OCGen™ Power System

(Spring 2013)


Next Steps

• Utilization of alternative codes to Flow-3D and ORCAFlex– AQWA

• Need exists for a more reliable geophysical interpretation methodology

1 | program name or ancillary texteere.energy.gov water power peer review ocgen™ module mooring...

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