It Blows You Away
Dec 18, 2015
"Coal, gas and oil will not be the three kings of the energy world for ever. It is no longer folly to look up to the sun and wind, down into the sea's waves"
Energy is a major input for overall socio-
economic development of any society
The prices of the fossil fuels steeply increasing
So renewables are expected to play a key role
Wind energy is the fastest growing renewable
Wind turbines are up to the task of producing
serious amounts of electricity
Force Strength km/h Effect
0 Calm 0-1 Smoke rises vertically
1 Light air 1-5 Smoke drifts slowly
2 Light breeze 6-11 Wind felt on face; leaves rustle
3 Gentle breeze 12-19 Twigs move; light flag unfurls
4 Moderate breeze 20-29 Dust and paper blown about; small branches move
5 Fresh breeze 30-39 Wavelets on inland water; small trees move
6 Strong breeze 40-50 Large branches sway; umbrellas turn inside out
7 Near gale 51-61 Whole trees sway; difficult to walk against wind
8 Gale 62-74 Twigs break off trees; walking very hard
9 Strong gale 75-87 Chimney pots, roof tiles and branches blown down
10 Storm 88-101 Widespread damage to buildings
11 Violent Storm 102-117 Widespread damage to buildings
12 Hurricane Over 119 Devastation
Beaufort Scale
Huge potential exists
Available potential can contribute five
times the world energy demand
0.4% contribution to total energy
Installed capacity (MW) in India
0
500
1000
1500
2000
2500
3000
3500
4000
90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05
State wise potential in India, 2005
0
2000
4000
6000
8000
10000
Gross Potential 8275 9675 6620 875 5500 3650 1700 5400 3050 450
Installed Capacity 120.6 253.53 410.75 2 28.85 456.15 2 284.76 2040.3 1.1
APGujara
tKarnat
akaKerala MP
Maharashtra
OrissaRajast
hanTN WB
MW
Turbine Evolution
Used for
• Pumping water
• Grinding grain
Mainly used for
• Generating Electricity
Types of turbines
VAWT
Drag is the main force
Nacelle is placed at the bottom
Yaw mechanism is not required
Lower starting torque
Difficulty in mounting the turbine
Unwanted fluctuations in the power output
HAWT
Lift is the main force
Much lower cyclic stresses
95% of the existing turbines are
HAWTs
Nacelle is placed at the top of the tower
Yaw mechanism is required
Counter Rotating HAWT
Increase the rotation speed
Rear one is smaller and stalls at high
wind speeds
Operates for wider range of wind speeds
Offshore turbines
More wind speeds
Less noise pollution
Less visual impact
Difficult to install and maintain
Energy losses due long distance
transport
Turbine design and construction
Blades
Material used
Typical length
Tower height
Heights twice the blade length are
found economical
Number of blades
Three blade HAWT are most efficient
Two blade turbines don’t require a hub
As the number increases; noise, wear and
cost increase and efficiency decreases
Multiple blade turbines are generally used
for water pumping purposes
Rotational control
Maintenance
Noise reduction
Centripetal force reduction
Mechanisms Stalling
Furling
Yaw Mechanism
To turn the turbine against the wind
Yaw error and fatigue loads
Uses electric motors and gear boxes
Wind turbine safety
Sensors – controlling vibrations
Over speed protection
Aero dynamic braking
Mechanical braking
Disc type wind turbine
o Much more efficient than
HAWT
o Requires less height
o Low noise
o Works in any wind direction
Determining Factors
Wind Speed
Turbine design and construction
Rated capacity of the turbine
Exact Location
Improvements in turbine design
Capital
Wind Speed Matters
Assuming the same size project, the better the wind resource, the lower the cost.
Energy Cost Trend
1979: 40 cents/kWh
Increased Turbine Size
R&D Advances
Manufacturing Improvements
2004: 3 – 4.5 cents/kWh
2000:4 - 6 cents/kWh
Typical cost statistics
Size: 51 MW
Wind Speed: 13-18 miles/hour
Capital cost: $ 65 million ($1300/MW)
Annual production: 150 million kW-hr
Electricity costs: 3.6-4.5 cents
Payback period: 20 years
Greater fuel diversity
No delay in construction
Low maintenance costs
Reliable and durable equipment
Additional income to land owners
More jobs per unit energy produced
No hidden costs
Germany now and 2020
At present 10% of the country’s energy is supplied by wind energy
By 2020 it is expected to go up to 26%
So…..
Price of wind power is coming down
There is enormous capacity
Energy storage, however, is still a problem
Visual impact Off shore turbines
Arrangement
Avian concerns Suitable choice of site
Using tubular towers instead of lattice tower
Using radars
Noise Varies as 5th power of relative wind speed
Streamlining of tower and nacelle
Acoustic insulation of nacelle
Specially designed gear box
Use of upwind turbines
Reducing angle of attack
Low tip speed ratios
Changes in wind patterns
Reducing turbulence
Intermittent
Coupling with hydro or solar energy
TV, microwave, radar interference
Switching from conducting material to
non-conducting and composite material
Wind energy is pollution free and nature
friendly
Wind energy has very good potential and it is
the fastest growing energy source
The future looks bright for wind energy
because technology is becoming more
advanced and windmills are becoming more
efficient