Wind Energy

1. WIND ENERGY
The ultimate renewable energy

2. Introduction
Wind power is extracted from air flow using wind
turbines or sails to produce mechanical or electrical
power.
Wind power as an alternative to fossil fuels, is
plentiful, renewable, widely distributed, clean,
produces no greenhouse gas emissions during
operation, and uses little land.
The net effects on the environment are far less
problematic than those of nonrenewable power
sources.

3. History
Wind power has been used as long as humans have
put sails into the wind.
Wind power was widely available and not confined
to the banks of fast-flowing streams, or later,
requiring sources of fuel.
The first windmill used for the production of
electricity was built in Scotland in July 1887 by
Prof James Blyth of Anderson's College,
Glasgow (the precursor of Strathclyde
University).

4. The Windmill
A windmill is a mill that converts
the energy of wind into
rotational energy by means of
vanes or blades.

5. Wind Turbine
A wind turbine is a device that converts kinetic
energy from the wind into electrical power.
The correct description for this type of machine
would be aerofoil-powered generator.
Arrays of large turbines, known as wind farms, are
becoming an increasingly important source of
renewable energy and are used by many countries
as part of a strategy to reduce their reliance on
fossil fuels.

6. Design and Construction

7. Design and Construction
Wind turbines are designed to exploit the wind
energy that exists at a location.
Aerodynamic modeling is used to determine the
optimum tower height, control systems, number of
blades and blade shape.
Conventional horizontal axis turbines can be
divided into three components: the rotor
component, the generator component, and the
structural support component.

8. Design And Construction
The rotor component, which is approximately 20% of the wind
turbine cost, includes the blades for converting wind energy to
low speed rotational energy.
The generator component, which is approximately 34% of the
wind turbine cost, includes the electrical generator, the control
electronics, and most likely a gearbox (e.g. planetary
gearbox),adjustable-speed drive or continuously variable
transmissioncomponent for converting the low speed incoming
rotation to high speed rotation suitable for generating
electricity.
The structural support component, which is approximately
15% of the wind turbine cost, includes the tower and rotor yaw
mechanism.

9. Wind Energy
Wind energy is the kinetic energy of air in motion, also
called wind. Total wind energy flowing through an
imaginary surface with area A during the time t is:
E = ¼mv2 = ¼(Avtp)v2 = ¼Atpv3
Where p is the density of air; v is the wind speed; Avt is
the volume of air passing through A (which is considered
perpendicular to the direction of the wind); Avtp is
therefore the mass m passing through "A". Note that ¼
pv2 is the kinetic energy of the moving air per unit volume.

10. Efficiency
Since conservation of mass requires that as much mass
of air exits the turbine as enters it. Betz's law gives the
maximal achievable extraction of wind power by a wind
turbine as 59% of the total kinetic energy of the air
flowing through the turbine.
Further inefficiencies, such as rotor blade friction and
drag, gearbox losses, generator and converter losses,
reduce the power delivered by a wind turbine.
Commercial utility-connected turbines deliver 75% to
80% of the Betz limit of power extractable from the wind,
at rated operating speed.

11. Advantages
The environmental impact of wind power when
compared to the environmental impacts of fossil
fuels, is relatively minor.
While a wind farm may cover a large area of land,
many land uses such as agriculture are compatible
with it, as only small areas of turbine foundations
and infrastructure are made unavailable for use.
The price of wind power is much more stable than
the volatile prices of fossil fuel sources.

12. Disadvantages
Wind power forecasting methods are used, but
predictability of any particular wind farm is low for
short-term operation. For any particular generator
there is an 80% chance that wind output will change
less than 10% in an hour and a 40% chance that it
will change 10% or more in 5 hours.
There are reports of bird and bat mortality at wind
turbines as there are around other artificial
structures.

13. Worldwide Distribution
Wind Power Production
United States
China
Spain
Germany
India
United Kingdom
France
Italy
Canada
Denmark

14. Thank You