1

WIND POWER-EXISTING & RECENT TRENDS

Electrical Engineering DepartmentINDIRA GANDHI INSTITUTE OF TECHNOLOGY

Sarang-759146, Dhenkanal, Orissa

1

9/4/2011

2

OUTLINE1.INTRODUCTION2.NATURE OF WIND3.WIND TURBINE & CLASSIFICATION4.WIND DATA, SPEED & ENERGY5.CAPACITY FACTOR & PENETRATION6.TURBINE PRODUCING ELECTRICITY7.FLYING POWER STATION8.AIRBORNE WIND TURBINE9.KITEGEN10.SMALL SCALE WIND POWER11.ADVANTAGES & DISADVANTAGES12.CONCLUSION

9/4/2011

3

INTRODUCTION• Wind energy is the kinetic energy of wind which flows due to the pressure

difference between two places, thus wind energy is an indirect form of solar energy

• No Green house emission. • Various new research works• Airborne wind turbine, Kitegen and Flying power station.

9/4/2011

4

NATURE OF WINDWinds are caused because of two factors:• The absorption of solar energy on the earth`s and in the atmosphere• The rotation of earth about its own axis and its motion around the sun Because of these two factors, alternate heating and cooling cycles occur,

differences in pressure are created, and the air is caused to move.

Most of the energy stored in these wind movements can be found at high altitudes where continuous wind speeds of over 160 km/h (100 mph) occur. Eventually, the wind energy is converted through friction into diffuse heat throughout the Earth's surface and the atmospheric pressure are created, and the air is caused to move.

9/4/2011

5

WIND TURBINE Wind turbines, like aircraft propeller blades, turn in the moving air and power an electric generator that supplies an electric current.

9/4/2011

6

WIND TURBINE’S CLASSIFICATION

Wind turbines are classified into: Horizontal Axis wind turbine Vertical Axis wind turbine

HAWT: In horizontal axis turbine, the rotor axis is horizontal and can be adjusted so that it is parallel to the direction of the wind stream. It is of 2 types based on the types of rotor used:

1.Multiblade type: The multi-blade rotor consists of a number of curved sheet metal blades which increase in width going outwards from the centre

2.Propeller type: : The propeller rotor consists of only two or three blades made from glass fibre reinforced plastic. The blades have aerofoil sections with a high thickness-to-chord ratio and yield a high lift relative to the drag.

9/4/2011

7

VAWT: In the vertical axis wind turbine, the rotor axis is vertical and fixed,

and is perpendicular to both the surface of the earth and the wind stream.Based on the type of rotor used, it is of two type:

1. Savinous type: The savinous rotor consists essentially of a hollow cylinder (approximately elliptical in shape) sliced in half, the halves being fixed to a vertical axis with a gap in between to make an S-shape.

2. Darrieus type: The darrieus rotor is shaped somewhat like an egg beater. It consists of two or three blades having an aerofoil cross section. Along the length, the blades are curved into a shape called a troposkein.

9/4/2011

8

HAWT VAWT

9/4/2011

9

WIND DATA &WIND SPEED NEEDED

Wind data: Vector quantity AnemometersWind speed needed: Minimum 16 kmph Wind speed increases with height & in

offshore regions. Rotate between 10 to 50 rpm.9/4/2011

10

ENERGY IN THE WIND -

α--

9/4/2011

11

CAPACITY FACTOR• The ratio of actual productivity in a year to this theoretical

maximum is called the capacity factor. • Typical capacity factors are 20–40%.

PENETRATION• Wind energy "penetration" refers to the fraction of energy

produced by wind compared with the total available generation capacity.

9/4/2011

12

HOW WIND TURBINE PRODUCES ELECTRICITY

WIND TURBINE GENERATORS • Generator is mounted in a nacelle that is located at the top of a tower behind the turbine’s rotor.

• At the other end, the generator is connected to the electrical grid.

• The generator needs to have a cooling system to make sure there is no overheating.

9/4/2011

13

SMALL GENERATORS: Require less force to turn than a larger ones, but give much

lower power output. Less efficient

i.e.. If you fit a large wind turbine rotor with a small generator it will be producing electricity during many hours of the year, but it will capture only a small part of the energy content of the wind at high wind speeds.

LARGE GENERATORS: Very efficient at high wind speeds, but unable to turn at low

wind speeds.

9/4/2011

14

FLYING POWER STATION

MODEL OF A GYROMILL • It looks something between a helicopter & kite.

• The plan is to send clusters of these vehicles 4.5 kilometres (14,700 feet) up into the jet stream to create a sort of flying power station.

• Each of the gyromills would be tethered to the ground.

• The cable connecting it to the ground can draw energy from the ground and use that energy to power the machine as a helicopter

9/4/2011

15

Contd.

A TYPICAL FLYING POWER STATION • when it gets to altitude, the gyromill’s motor can be switched to a generator and energy is pushed back down the cable to the ground.

• The power station would cover an area about 20 kilometres (12 miles) in diameter.

• To bring them down, we would simply winch them in - or you could fly them down.

9/4/2011

16

AIRBORNE WIND TURBINE

TURBINE COMPONENTS• AXLE• SAIL• RUDDER• GAS• GENERATOR• TETHER

9/4/2011

17

MARS

MARS POWER STATION• MARS is an innovative lighter-than-air

tethered device that rotates about a horizontal axis in response to wind.

9/4/2011

18

KITEGEN

KITEGEN POWER STATION • Wind is captured by Power Wing Profiles (power kites) whose movements are controlled automatically by a computer.

• About twenty automatically controlled kites can keep rotating a turbine of 1,600 meters diameter at a speed of 15 revolutions per hour.

• This can generate 1 Gigawatt of power, equivalent to a medium size nuclear power station .

• A unit called KSU1 used a kite that flew to 800 meters with automatic controls.

9/4/2011

19

SMALL SCALE WIND POWER

Rooftop wind turbine

• Capacity of production is up to 50 kw.

• Alternative of DG in homes.• Grid-connected wind turbines

may use grid energy storage, displacing purchased energy with local production when available.

• Equipment such as parking meters or wireless Internet gateways may be powered by a wind turbine that charges a small battery.

9/4/2011

20

ADVANTAGES DISADVANTAGES

• Very inexpensive and not very hard to implement.

• Environmental effects of wind power are relatively minor.

• No fuel charges.• Most wind catching

systems are very small.

• Present widely used designs of wind power are not very efficient .

• Wind power system causes visual pollution .

• Wind power cannot be used everywhere.

• Deadly for birds

9/4/2011

21

CONCLUSIONVarious new techniques that are covered here are great future prospects for

our power requirement fulfillment. Wind power is renewable & does not cause pollution. Efficient techniques of wind power utilization can solve our energy crisis of the future.

9/4/2011

22

REFERENCES

9/4/2011

• “SOLAR ENERGY”, PRINCIPLES OF THERMAL COLLECTION & STORAGE (2nd edition) by S.P.SUKHAMTE.

• “ALTERNATIVE ENERGY SOURCES III”, PART A: WIND ENERGY/STORAGE/PRODUCTION by T.NEZAL VEZIROGLU.

• HANNELE HOLTTINEN, et al (Sept 2006) “DESIGN & OPERATION OF POWER SYSTEMS WITH LARGE AMOUNTS OF WIND POWER” IEA WIND SUMMARY PAPER.

• DAVID COHN “WINDMILLS IN THE SKY”.• KITEGEN PROJECT, CANALE, M. FAGIANO, L. MILANESE, M. IPPOLITO.• TOMORROWS WORLD (BBC NEWS), WORLD ENERGY COUNCIL, PROFF.

BRYAN ROBERTS.