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Harvesting from Wind EnergyMinoru Taya
University of Washington
January , 2016
"Wind power isn't the silver bullet that will solve all our energy challenges—there isn't one. But it is a key part of a comprehensive strategy to move us from an economy that runs on fossil fuels to one that relies on more homegrown fuels and clean energy."
President Barack Obama, April 2010
Under conservative assumptions about transmission, fossil fuel supply, and supply chain availability, the United States could feasibly build 54 GW of offshore wind power by 2030.
20% Wind Energy by 2030, U.S. Department of Energy, July 2008
Wind energy Sustainable clean energy
Northern European countries are using wind energy extensively, first in land now into sea to havest even higher wind energy. Pacific northwest and Hawaii and mid-west have stronger wind area , ideal for wind energy harvesting sites. 24 hours/day based energy availability unlike solar cells which is only 8 hours/day
Technical challenges are:
Maintenance cost is higher for longer time
Processing of longer span turbine blades of up to 150 m diameter and its transportation to the final site
Economics of wind energy, EWEA, Soren Kohn ed, 2007
More and more larger sized wind energy system is deployed in sea, where stronger wind velocity is available for longer time without disturbing human activities, example North Sea and Scandinavian Coastal Sea Water.
Figure 3. Status of offshore wind energy technology
Figure 2. United States offshore wind resource by region and depth for annual average wind speed sites above 7.0 m/s.
Figure 1. Nameplate generating capacity of offshore wind projects (1991–2010)
Figure 4 Average wind speed for last 54 years through2002
Wind energy explained (Manwell et al, 2002)
Wind energy explained (Manwell et al, 2002)
Wind energy explained (Manwell et al, 2002)
Wind energy explained (Manwell et al, 2002)
Wind energy explained (Manwell et al, 2002)
Wind energy explained (Manwell et al, 2002)
Wind energy explained (Manwell et al, 2002)
Wind energy explained (Manwell et al, 2002)
Wind energy explained (Manwell et al, 2002)
Structural health monitoring wind turbine blades
Rumsey and Paquette, 2010
Wind energy explained (Rumsey and Paquette, 2010)
Rumsey and Paquette, 2010
Rumsey and Paquette, 2010
Rumsey and Paquette, 2010
3-point bending of composite plates clamped by Fe-SMA joint
• No bonding between surfaces of polymeric composite plates and Fe-SMA pin-washer
• 0.2 of friction coefficient is applied between contact surfaces
• Quarter model (green portion) is used for FEA
Full model
130mm
5.7mm
5.7mmComposite plates
Composite plates
Fe-SMA
Quarter modelExternal loading (3.3KN)
Width of plate in quarter model is 22.75mm
Z
XY
Vertical gap
Horizontal gap
40mm
Key parameters: Horizontal gap = 0.02mm Vertical gap = 0mm Pin diameter = 5.98mm
head
washer
42
Three point bending testSample: Fe-15.84Mn-6.24Si-11.16Cr
Results
After the testing
Back side
Length: 75m (2 sections: 25m + 50m)
Height: from 4m (blade hub) to 0.325m (blade tip)
Width: 1.2m
Spar cap thickness: 0.1m
Shear web thickness: 0.086m
FEA model of spar cap and shear web
Side view
100mm
15
140mm
80
15
Spar cap
Shear web
Fe-SMA joint
10
Spar cap
0.6m0.1m
0.6m
K. Coxa, A. Echtermeyerb, “Structural design and analysis of a 10MW wind
turbine blade”, Energy Procedia 24 ( 2012 ) 194 – 201
Loading along the spar cap
Half model
Clamping of Fe-SMA joint on composite plates
• Same size of joint
• Horizontal gap: 0.5mm
• Vertical gap: 0mm
• Composite: same as Spar cap
(E-LT-5500/EP-3)
XX
ZZ
Pa
top
composite
plate
bottom
composite
plate
Z
X
Y
-700
-600
-500
-400
-300
-200
-100
01 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Str
es
s (
MP
a)
ZZ
XX
Along pin in Z direction
Stresses in the composite near pin (red line)
Top plate bottom plate
Pa
Predicted results around the joint due to the loading
7mm gap
meter
Displacement in Z
XX in joints
• The structure tip exhibits 4.5m displacement in Z
• 7mm gap is found in the joint section
• Max. XX in the pin is about +600MPa
• Max. XX in the clear hole is about +375MPa
• Max. shear stress in the pin on the shear web is about 100MPa
• More joints are needed in the spar cap to reduce the gap
between jointed sections and stresses due to wind loading on the
turbine blade.
Z
X
Y
XX in clear holes in the top spar cap
ZX
Y
Wind energy based on lens-turbine system by Prof. Ohya of Kyushu University• Use of lens-wind energy design is desired for the area where less
wind velocities are available. Circular case which surrounds wind turbine blades, will enhance the wind velocity inside the circular case.
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Tension(KgW)
Boinspired design of wind turbine blades for windy areas
Non-flat surface of a dragon fly gives us a good design of wind turbine blades which can be effectively used for those areas of less strong winds.
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