Jim Platts Manufacturing Engineering mjp@eng.cam.achemh1/climate/IB_P8_wind_2008_Platts.pdf · Wind...

Wind energy turns to Bamboo

Jim Platts

Manufacturing Engineering

mjp@eng.cam.ac.uk

LET’S LOOK AT THE WIND

ENERGY INDUSTRY.

• It employs over 100,000 people

in Europe. Globally:-• Jan07-Jan08 turnover $20.0bn.

• 20,000MW installed in 12 months.• More than 93,000MW world-wide.

• More than 57,000MW in Europe.

• 22% of Denmark’s electricity.• 34% in Schleswig-Holstein.

• 26.6% pa growth rate.• EU directive targets 22% European

electricity from renewables by 2010.

• EWEA targets 75,000MW by 2010• 172,000MW world-wide by 2010,

turnover over $25bn pa.

From Jan07 to Jan08 that meant over 10000 turbinesin typical sizes of

70m dia. 1.5MW

80m dia. 2.0MW90m dia. 2.5MW

The industry produces 120 blades a day.

Future wind energy growth

I was involved in creating the wind energy industry in the 1980’s. By the mid 1990’s it was becoming clear that the industry was conceptually stuck. For the last decade, my intention has

been to bring through the next generation of wind turbine concepts

and change the cost equation for wind energy so that it is

truly cost competitive with any energy source, without political

support.

The development of technical composites since

1980 (1)

cost

performance

Low cost

glassfibre

Aerospace

composites

Tec

hn

ical

com

pos

ites

The development of technical composites since

1980 (2)New high performance epoxy resins (SP Systems)

New high performance glass and carbon stitched fabrics (Techtextiles)

Wood composites (Composite Technology)

New large scale manufacturing processes

-----------------

All high performance ocean racing yachts

(rewrote the America’s Cup design rules)

Wind turbine rotor technology

(two companies on the Isle of Wight employ 1000 people, turnover £100m)

(European wind turbine rotor industry turnover £2bn)

European wind energy industry employs 100,000 people, turnover £10bn)

(growing at > 25%pa)

The best blades are made of wood

Veneers, glass-cloth and epoxy.

WOOD MICROSTRUCTUREWOOD MICROSTRUCTURE

Ecological PerformanceEcological PerformanceMaterial Energy Stiffness Strength Energy/ Energy/

Stiffness Strength

(GJ/m3) (Gpa) (Mpa) (J/Nm) (kJ/Nm)

Aluminium (Extrusions) 800 70 300 11.4 2.67

Steel (Grade 43 sections) 500 210 275 2.4 1.82

GRP (UD Glass/Polyester) 250 40 300 6.3 0.83

CFRP (UD carbon/Epoxy) 500 125 900 4.0 0.56

Wood (Finnish Birch) 3.8 16 80 0.24 0.048

TYPICAL WOOD COMPOSITE BLADE STRUCTURE

Manufacture of Wood Composite

Blades

Machining root end

WEIGHT BREAKDOWN

Glass

Wood

Resins

Components

Demands for a New Blade Technology

• Production Rate 2 day – 1 day – 12 hour

• Anywhere in world

• Lighter blades for offshore - size

• Improved Health & Safety

Near Term Material OptionsNear Term Material Options

••Glass Polyester, Wet lay upGlass Polyester, Wet lay up - Cheap, heavy, stiff

••Wood Epoxy, Wet lay Vacuum ConsolidatedWood Epoxy, Wet lay Vacuum Consolidated - Cheap,

lighter, stiffer

••Glass Carbon Epoxy,Glass Carbon Epoxy, InfusedInfused - More expensive, light, flexible

••Glass Carbon Epoxy, Glass Carbon Epoxy, Prepreg Prepreg -Most expensive, lightest, most

flexible

••Wood Carbon Epoxy, InfusedWood Carbon Epoxy, Infused-- Cheap, lightest, stiffest

Answer Answer –– Wood Carbon Strip Wood Carbon Strip

InfusionInfusion

• Wood cheap & Carbon (3%) Light

• Vacuum Infusion with strips– Health & Safety – dry materials

– Speed with high solids & low resin volume – shrinkage & distortion

– Low temperature robust tools

• Lower cost materials –than prepreg

Relative Blade WeightsRelative Blade Weights

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

GRP Polyester Wood

Composite

Infused GRE Prepreg GRE Infused Wood

Carbon

Weight

Cost

(achieved)

Process improvementsWood composite

Open moulds

Clean moulds

Gel coat

Cure

Outer glasscloth

Cure

Wood veneers

Vacuum

Cure

Peel and trim

Inner glasscloth

Cure

Trim

Joining adhesive

Place webs

Join moulds

Cure

Drill stud holes

Place studs

Cure

20 steps

2 days

Infused wood carbonOpen moulds

Clean moulds

Gel coat

Cure

Place all dry material

Vacuum

Infuse

Cure

Peel and trim

Joining adhesive

Place webs

Join moulds

Cure

13 steps

1 day

…. And 12 hours is possible

Wood lay-up

Root Fixings built in for infusion

40m Blade Infusing

40m Web placement

Mould closure

This is at 30% overload.

Developing better wind

turbines

(capture more energy)

(use less material)

Developing better blade

shapes

Comparing two blades

Old blade, 23.5m, 3.2 tonnes

New blade, 25m, 2.7 tonnes

Thickness and twist

Power Curves

Thrust

Bending Moment

Typical current cost

distribution

Rotor 29%

Drive train 10%

Generator 25%

E-system/converter 15%

Tower 12%

Nacelle 3%

Yaw mechanism 3%

Transformer 2%

Hydraulics 1%

Are there things you can do to the rotor at no cost, to get more out of

it and out of the generator/electrical system and the tower?

Yes! We haven’t finished yet. If you really want

To get them Ryle’d, you do what Professor Sir

Martin Ryle, Astronomer Royal, was doing in

Cambridge in 1980. He said it was far more

Efficient to survive highWinds like a palm tree

Than like an oak tree.So you let the blades

Hinge. And you can

Capture 50% moreEnergy using 2/3 of

The material.Like this….

Coning rotors

0

200

400

600

800

1000

1200

1400

1600

0.0 5.0 10.0 15.0 20.0 25.0

U (m/s)

V80 (scaled) CONE-1500 LS

A coning rotor produces a very favourably shaped power curve.

0

5

10

15

20

25

30

35

40

0 5 10 15 20 25

U (m/s)

0

200

400

600

800

1000

1200

1400

1600

Pe

lec (

kW

), T

hru

st

(kN

),

To

rqu

e (

kN

m)

Cone angle Pelec Thrust Torque

The thrust and torque are well controlled by the coning.

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

2.0 4.0 6.0 8.0 10.0 12.0

Vavg (m/s)

0

20

40

60

80

100

120

140

CONE-1500 LS V80 (scaled) % Advantage

It gives a higher energy capture than a

similarly rated conventional machine.

The blade bending moment curve is

greatly reduced by the coning.

Optimising wind turbine designs in China

Design machines with high capacity factors and

Use cost-effective Chinese materials

Long transmission

distancesSmooth wind

conditions

Blade material

Ecological PerformanceEcological PerformanceMaterial Energy Stiffness Strength Energy/ Energy/

Stiffness Strength

(GJ/m3) (Gpa) (Mpa) (J/Nm) (kJ/Nm)

Aluminium (Extrusions) 800 70 300 11.4 2.67

Steel (Grade 43 sections) 500 210 275 2.4 1.82

GRP (UD Glass/Polyester) 250 40 300 6.3 0.83

CFRP (UD carbon/Epoxy) 500 125 900 4.0 0.56

Wood (Finnish Birch) 3.8 16 80 0.24 0.048

Bamboo 3.8 25 120 0.15 0.032

Typical current cost

distribution

Rotor 29%

Drive train 10%

Generator 25%

E-system/converter 15%

Tower 12%

Nacelle 3%

Yaw mechanism 3%

Transformer 2%

Hydraulics 1%

Are there things you can do to the drive train and generator at no cost,

to get more out of them and out of the rotor and the tower?

Rare Earth Permanent Magnet Air

cooled direct drive generators

Generator efficiency

The Fray-Farthing-Chen Cambridge Process, developed by the materials science group at

Cambridge University and now being commercialised by a spin-off company called

Metalysis, is a simple one-step electrochemical technology in which metal oxide is directly reduced to metal powder in the solid state, using no exotic

chemicals. This will greatly reduce the cost of Rare Earth material extraction for permanent magnet

generators

Performance of the FFC Cambridge Process

Inner Mongolian wind conditions

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.0 5.0 10.0 15.0 20.0 25.0V (m/s)

6.76 m/s , k = 2

6.76 m/s , k = 2.26.76 m/s , k = 2.52

8.57 m/s , k = 2

8.57 m/s , k = 2.28.57 m/s , k = 2.52

Wind speeds for a Northern Chinese site through the year/day.

Hourly average Coned 1500 rotor power output from this site.

CONE-1500

China wind data @ 40m height

Diurnal averages across winter (Dec 20 - March 20) and summer (June 20 - Sept 20)

Vavg (m/s) k Eann (GWh) CF Vavg (m/s) k Eann (GWh) CF

100

Summer 7.21 5.47 0.42 7.31 5.60 0.43

Winter 9.18 7.84 0.60 9.12 7.74 0.59

80

Summer 6.99 5.15 0.39 7.08 5.29 0.40

Winter 8.90 7.55 0.57 8.84 7.45 0.57

40

Summer 6.34 2.55 4.21 0.32 6.43 2.42 4.37 0.33

Winter 8.08 2.52 6.61 0.50 8.02 2.47 6.52 0.50

Day is from 07:00 - 19:00 averaged throughout the year (+- 1hr variation)

Tower height (m)

Day Night

Average capacity factor 0.51 (0.42 Summer, 0.59 Winter).

(Typical European capacity factors are 0.2 - 0.25.)

Next GenerationWind Turbine Development -

in China

Advanced, high tip speed

Composites rotor technology

Rare Earth permanent magnet

Direct drive generators

R y l e T e c h n o l o g y

The intention is to produce the best wind turbines in the world

- in China

And change the cost equation for wind energy so that it is

truly cost competitive with any energy source, without political

support.

Ryle Technology Company Structure

60% of gross profits reinvested in further development of the company

10% of gross profit distributed as bonus to all staff

30% declared as profit and distributed to shareholders

2 founder shareholders 4% and 6%

90% of shares held in trust by the Ryle Foundation