Questions_For_BAA_Renewable_Energy___E15PS00085_Responses.pdf

Questions: Broad Agency Announcement for Renewable Energy

BAA Number: E15PS00085

1. Laboratory Testing of Lateral Load Response for Monopiles in Sand

1. Regarding the installation type, are the monopiles driven or suction piles?

Project should model driven monopiles.

2. Development of Guidelines for Structural Health Monitoring for Offshore Wind Turbine Towers and Foundations

2. Is it required to add optimization of the sensor to the guidelines? No

3. Is the guidelines for the floating and fixed wind turbines? Both

3. Breaking Wave Loads on Offshore Wind Turbines

A CFD model should be used with metocean data to provide a better method of assessing wave loads on various wind turbine foundation types, including the effect on fatigue and pile capacity.

The deliverable is ambiguous for this topic.

4. Is BSEE looking for

a. A CFD methodology (procedure) for performing breaking wave analysis on wind turbine foundations?

b. A CFD (numerical) tool for performing breaking wave load analysis on wind turbine foundations?

c. An analytical method (based on CFD) to determine breaking wave loads on wind turbine foundations?

d. A comparison between CFD and analytical methods for predicting the breaking wave loads on foundations?

We are looking for item d.

4. Cyclic Loading on Suction Bucket Foundations

5. The range of soil conditions in the OCS is very broad. Can the scope be limited to clayey soils only?

6. Suction piles, suction caissons and suction buckets are preferred for applications in clayey soils and encounter installation difficulties in sandy soils. Does BSEE want to investigate the possibility of the use of wind turbines with suction bucket foundations in sandy soil as part of the scope of ‘Cyclic Loading on Suction Bucket Foundations’?

We realize that suction buckets have been primarily used in clay soils in the Gulf of Mexico and are not suitable for rocky gravelly glacial soils off New England. The designated Wind Energy Areas in the Atlantic Outer Continental Shelf have primarily granular sediments with little or no clay exposed at the seabottom. The study should assume fine sand-silt soils comparable to sites off the mid-Atlantic as part of the assessment of the suitability of suction buckets in this region.

5. Assessment of Partially verses Fully Coupled Dynamic Analysis of offshore Wind Turbines

7. Is floating wind turbine the interested research target? No. Target is fixed bottom turbines.

8. What is the key component of interest for coupled or partial dynamic analysis? Is it the dynamic response and loads of the wind turbine itself? What about wind, wave and current load on the supporting structure itself as the methodology is already available commercially?

We are looking for a comparison of the approach where the WTG and foundation designer perform analyses independently using different models (partially coupled or sequential coupled) and the fully coupled or single analysis approach using only one model for the entire structure.

9. Should model tests be considered? No new model testing should be included.

10. If for floating wind turbine, what should be considered for coupled dynamic analysis? Floating wind turbines not included.

a. Rigid body dynamic coupled with environmental (hydrodynamic, aerodynamic) and station keeping loads (mooring or tendon). This is more feasible with current technology development.

b. Structural dynamic coupled with environmental (hydrodynamic, aerodynamic) and station keeping loads (mooring or tendon). This will be very difficult, only achievable with significant simplification and assumptions.