It Blows You Away
"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"
Introduction
Energy is a major input for overall socioeconomic 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
Principles
Uneven heating of earth s surface and rotation
Beaufort Scale 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
Velocity with Height
Power vs. Velocity
Lift and drag forces
Solidity and Tip speed ratio
Performance co-efficient and Betz criterion
Potential
Huge potential exists Available potential can contribute five times the world energy demand 0.4% contribution to total energy
Wind is currently the world s fastest growing energy source
Growth of Wind Energy Year
Wind Energy generating capacity by country, 1980-2003
Installed Capacity (MW) in 2005
Available potential in India
Wind Power Density of India
All India Fuel wise Installed Capacity, 2004 Wind 3% Diesel 1% Nuclear 2% Hydro 26% Coal 58% Gas 10%
Installed capacity (MW) in India 4000 3500 3000 2500 2000 1500 1000 500 0 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05
State wise potential in India, 2005 10000 8000 M W 6000 4000 2000 0 AP Gujara t Karnat aka Kerala 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 MP Mahar ashtra Orissa Rajast han TN WB
Technology
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
Two types of HAWT DOWNWIND TURBINE UPWIND TURBINE
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
A Typical HAWT
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
Improvements Concentrators
Future Wind Turbines Wind Amplified Rotor Platform
Disc type wind turbine o Much more efficient than HAWT o Requires less height o Low noise o Works in any wind direction
Economics
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.
Size Matters Assuming the same wind speed of 8.08 m/s, a large wind farm is more economical
Overall cost distribution
Break down of capital cost
Energy Cost Trend 1979: 40 cents/kwh 2000: 4-6 cents/kwh Increased Turbine Size R&D Advances Manufacturing Improvements 2004: 3 4.5 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
Economic Advantages
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
Future
Wind Capital Cost
Cost of Wind Energy
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%
Australia now and 2040
So.. Price of wind power is coming down There is enormous capacity Energy storage, however, is still a problem
Typical Concerns
Visual impact Off shore turbines Arrangement Avian concerns Suitable choice of site Using tubular towers instead of lattice tower Using radars
Noise Varies as 5 th 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
Conclusion
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
THANK YOU
Furling