BLACKBIRD: Storage Base Single Anchored Uniaxial Hybrid Vertical Axis Wind Turbine [VAWT]and Wave Energy Convertor [WEC] on Tension Leg Buoy – AWEA Offshore Rhode Island 2016

SummaryEarly developments in Offshore Wind [OW] have been in shallow water, primarily the southern North Sea, with turbines up to 8 MW founded on steel monopiles or piled truss towers (“jackets”). There are increasing indications that Floating Offshore Wind Turbine [FOWT] array size projects could become commercially viable beyond 2020.The feasibility of Vertical Axis FOWT and Wave Energy Convertor [WEC] technology is at an early stage, but costs are expected to reduce. WEC development has been patchy and irregular Prototypes are undergoing long term testing to prove reliability, operability and durability [4].

Dr.C.R. Golightly, BSc, MSc, PhD, MICE, FGS .Geotechnical and Engineering Geology Consultant, Rue Marc Brison 10G, 1300 Limal, Belgium, Tel: +32 10 419525 Mobile: +32 478 086394 e-mail: chris.golightly@hotmail.com skype:chrisgolightly Linked In: www.linkedin.com/pub/5/4b5/469 Twitter: @CRGolightly Academia.edu: https://independent.academia.edu/ChristopherGolightly“You Pay for a Site Investigation - Whether You do One or Not”– Cole et al, 1991. “Ignore The Geology at Your Peril” – Prof. John Burland, Imperial College.

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of an Undersea Energy Storage Concept, Proc. IEEE, 101(4): pp. 906–924, 2011.14. White, C.N., Erb, P.R. and Botros, F.R.: The Single-Leg Tension-Leg Platform: A Cost-Effective Evolution of

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Seabed Anchored Foundation Template [SAFT]SAFT [7] is a buoyant floated-out hybrid GRP/reinforced concrete subsea foundation designed to support tripods, jackets or GBS or pre-installed for taut (TLP) or catenary mooring lines/tethers templates.Steel or concrete edge skirts, suction caissons [SC] , anchor piles or helical screw are options available for a wide variety of different soil overburden types and thicknesses and geological rock strata.Tensile pressure grouted, fully proof loaded single or multi-strand rock anchors are installed through support casing, using an ROV marinised drilling unit. External GRP, concrete or steel mudmats and integral plastic anti-scour frond mats/mattresses provide support and scour protection. The SAFT unit has high lateral load resistance and tension uplift capacity, especially anchored into bedrock.Design is preceded by high quality seabed geophysical investigation followed immediately by confirmatory geotechnical soil and rock coring, with the same ROV drilling unit used for anchor installation.

1. Twin bladed Carbon Fibre Vertical Axis Wind Turbine [VAWT]

2. VAWT Generator3. Anti Yaw Swivel Bearing4. WEC Power Take Off [PTO] Unit Integrated

into Floater.5. Composite Heave Plate Wings6. Linear Magnetic-Geared Interior

Permanent Magnet Generator [LMGIPMG] [5]

7. Inner Stationary Stator Coils8. High Buoyancy Uniaxial Submerged

Tension Leg Buoy [USTLB]

Combined wind-wave energy potential is enormous [3,8,12], Recent work on hybrid concepts [1.4] is only theoretical but promising. The TRL level 2 BLACKBIRD is a potential “gamechanger” VAWT-WEC uniaxially tethered hybrid, a synergy of existing VAWT, WEC combinations and PTOs [5,9,11], TLP/TLB mooring [10,14] and local pumped energy storage [6,13] concepts. Fig. 2 shows the energy potential existing off the NW coasts of Europe.

European Offshore Wind – Need to Reduce Rising CostsThe majority of European OW turbines installed or planned in the German, UK and Danish sectors of the North Sea have been scaled up conventional onshore triple bladed horizontal axis wind turbines [HAWT], founded mainly on large diameter (4 to 8 m) steel monopiles (WD <35m) or piled tripods/jackets (WD ~ 30 to 55m), with some concrete GBS. Costs must be halved or more for industry survival without subsidies. CAPEX rose between 2005 and 2010 (Fig. 1).

9. Tension Leg Buoy Bottom Connector10. Single Vertical High Capacity

Damped Tether/Tendon.11. Subsea FRP “Green” Concrete

Storage, Pump& Electrolysis Unit.12. Subsea Ball & Taper “Plug-In”

Seabed Connector13. Seabed Rock Anchored Foundation

Template [SAFT]14. Export HVDC Power Line plus Gas

Pipeline.15. Grouted Rock Anchors and Suction

Caissons

Figure 3 – BLACKBIRD - Summary

LCOE: from > 200 USD/MWhr

to ~ 50 USD/MWhr

Figure 1 – Reducing LCOE [USD per MWHr]Sources: Carbon Trust [2]; Bloomberg New Energy Finance

Figure 2 – European Combined Wind & Wave Energy PotentialSource: ORECCA

Dr. C.R. Golightly, BSc, MSc, PhD, MICE, FGS.Geotechnical and Engineering Geology Consultant, Belgium