As of October, 2002, there is more than 4,300 MW of wind power capacity installed in the U.S. The 10 billion kWh currently generated by wind plants in the U.S. each year displaces some 13.5 billion pounds (6.7 million tons) of carbon dioxide, 35,000 tons of sulfur dioxide, and 21,000 tons of nitrogen oxides. The power that is produced from the wind is still less than 1% of the country’s total electricity production. With the right policy and market incentives, wind power technology can provide more than 6% of the nation’s electricity by 2020, which is roughly equal to an installed capacity base of 100,000 MW. That would produce enough electricity for 25 million homes and displace approximately 160 million tons of carbon dioxide, 840,000 tons of sulfur dioxide, and 503,000 tons of nitrogen oxides.
The fact that electricity produced with wind power does not emit harmful pollutants or burn resources is an obvious advantage of the technology. In addition, it can provide cost stability to a utilty’s resource portfolio and bring income and tax benefits to rural communities.
Because the power that can be converted to electricity varies by the area swept by the rotor, a designer can dramatically increase the electricity output by making the blades longer.
Larger turbines produce exponentially more power, which reduces unit cost of electricity Rotor blade airfoils specially designed for wind turbines Power electronics improve turbine operations and maintenance Computer modeling produces more efficient design
The capacity factor assess the productivity of a wind turbine, comparing the actual production with the amount of power the plant would have produced if it had run at full capacity the same amount of time. Since a wind plant uses the wind for its fuel, and the wind does not constantly blow at full speed, modern wind turbines have capacity factors that range from 25%-40%, although they will probably achieve higher capacity factors during windy months. It is important to note that while capacity factor is almost entirely a matter of reliability for a fueled power plant, it is not for a wind plant—for a wind plant, it is a matter of economical turbine design. With a very large rotor and a very small generator, a wind turbine would run at full capacity whenever the wind blew and would have a 60-80% capacity factor—but it would produce very little electricity. The most electricity per dollar of investment is gained by using a larger generator and accepting the fact that the capacity factor will be lower as a result. Wind turbines are fundamentally different from fueled power plants in this respect. If a wind turbine&apos;s capacity factor is 33%, it does not mean that it is only running one-third of the time. A wind turbine at a typical location in the Midwestern U.S. should run about 65-80% of the time. However, much of the time it will be generating at less than full capacity (see previous answer), making its capacity factor lower.
Wind power PRESENTATION
A Renewable Source of Energy
Sanjana and Alekhya
Year EEE Department
Energy is basically classified into 2 categories.
Renewable and Non Renewable.
Non Renewable sources are Coal, Petrol etc...
Renewable Sources are Solar, Biomass, Wind, Water etc…
Wind Energy Outline
Wind Energy History
1200 to 1850
Golden era of windmills started in western Europe –
Multiblade turbines for water pumping made and
marketed in U.S
1850 – 1930
As many as 6,000,000 units installed in US Midwest
US Rural Electrification Administration extends the grid to
isolated rural sites.
Grid Electricity rapidly displaced multiblade turbines
Wind Energy - What is it?
All renewable energy (except tidal and
geothermal power), ultimately comes from
The earth receives 1.74 x 1017
power (per hour) from the sun.
About one or 2 percent of this energy is
converted to wind energy
(which is about 50-100 times more
than the energy converted to
biomass by all plants on earth).
Differential heating of the earth’s surface
and atmosphere induces vertical and
horizontal air currents that are affected by
the earth’s rotation and contours of the
Ex: Land Sea Breeze Cycle
A Windmill captures wind
energy and then uses a
generator to convert it to
The design of a windmill
is an integral part of how
efficient it will be.
When designing a
windmill, one must decide
on the size of the turbine,
and the size of the
Increasingly Significant Power Source
by 2020.Wind currently produces less than
1% of the nation’s power.
Source: Energy Information Agency
Advantages of Wind Power
Fuel Diversity & Conservation
Cost Stability Benefits
Pollution from Electric Power
0% 20% 40% 60% 80%
Toxic Heavy Metals
Percentage of U.S. Emissions
Electric power is a primary source of industrial air pollution
Density = P/(RxT)
P - pressure (Pa)
R - specific gas constant (287 J/kgK)
T - air temperature (K)
= 1/2 x air density x swept rotor area x (wind speed)3
ρ A V3
Area = π r2 Instantaneous Speed
(not mean speed)
Power in the Wind (W/m2
Technical Factors affecting site selection:
High Average annual wind speed
Low Cost of Construction
Close Distance from Utility line or customers
Prevailing wind Direction
Obstacle Height, Dis >5OH, OH, <0.5HH
Birds - A Serious Obstacle
Cost of Wind Turbine
Threat to Wildlife
Wind Can Never Be
Suited To Particular Region
Wind Energy Natural Characteristics
Blade swept area
Improved Capacity Factor
Performance Improvements due to:
Larger turbines/energy capture
Capacity factors > 35% at good sites
Examples (Year 2000)
Big Spring, Texas
37% CF in first 9 months
36% CF in first 9 months
Expectations for Future Growth
20,000 total turbines installed by 2010
6% of electricity supply by 2020
India now ranks as a “wind superpower” having a net
potential of about 45000 MW only from 13 identified states.
100,000 MW of wind power
installed by 2020
The Future of Wind - Offshore
• 1.5 - 6 MW per
• 60-120 m hub
• 5 km from shore,
30m deep ideal
• Gravity foundation,
pole, or tripod
• Shaft can act as
• Drawbacks- T&D
cables lead to shore)
and visual eye sore