Thw Ultimate Power Solution

The Power Solution Concern:

The world is developing day by day. And also new problems are creating. Power Problem is one of them. In fact today the scarcity of power is quite remarkable. As the world is getting industrialized the demand of power is increasing double every year. Coal, gas, petroleum etc fuel energy are decreasing from the world day by day as demand is increasing. The moment will come in the near Future when there will no fuel left in the world. So what will happen then? The world will stop then?
The answer is difficult. Today all the developing countries of the world are trying to produce the electricity from the natural source which will not exhaust. Like Solar energy, wind energy, sea tide energy, Bio gas etc. In this blog I will focus in Wind energy .

What is Wind Energy?

Air is invisible material. But we are feeling it all the time. The strength of wind can be felt after cyclone or tornado when its sample is seen around the affected area. When air moves quickly, in the form of wind, those particles are moving quickly. Motion means kinetic energy, which can be captured, just like the energy in moving water can be captured by the turbine in a hydroelectric dam. Wind power all starts with the sun. When the sun heats up a certain area of land, the air around that land mass absorbs some of that heat. At a certain temperature, that hotter air begins to rise very quickly because a given volume of hot air is lighter than an equal volume of cooler air. Faster-moving (hotter) air particles exert more pressure than slower-moving particles, so it takes fewer of them to maintain the normal air pressure at a given elevation.

If you place an object like a rotor blade in the path of that wind, the wind will push on it, transferring some of its own energy of motion to the blade. This is how a wind turbine captures energy from the wind. The same thing happens with a sail boat. When moving air pushes on the barrier of the sail, it causes the boat to move. The wind has transferred its own energy of motion to the sailboat.

Parts inside a Wind Turbine:

Inside a wind Turbine there are lots of hi-tech equipments and parts. Lets look at them:

Anemometer:

Measures the wind speed and transmits wind speed data to the controller.

Blades:

Most turbines have either two or three blades. Wind blowing over the blades causes the blades to "lift" and rotate.

Brake:

A disc brake, which can be applied mechanically, electrically, or hydraulically to stop the rotor in emergencies.

Controller:

The controller starts up the machine at wind speeds of about 8 to 16 miles per hour (mph) and shuts off the machine at about 55 mph. Turbines do not operate at wind speeds above about 55 mph because they might be damaged by the high winds.

Gear box:

Gears connect the low-speed shaft to the high-speed shaft and increase the rotational speeds from about 30 to 60 rotations per minute (rpm) to about 1000 to 1800 rpm, the rotational speed required by most generators to produce electricity. The gear box is a costly (and heavy) part of the wind turbine and engineers are exploring "direct-drive" generators that operate at lower rotational speeds and don't need gear boxes.

Generator:

Usually an off-the-shelf induction generator that produces 60-cycle AC electricity.

High-speed shaft:

Drives the generator.

Low-speed shaft:

The rotor turns the low-speed shaft at about 30 to 60 rotations per minute.

Nacelle:

The nacelle sits atop the tower and contains the gear box, low- and high-speed shafts, generator, controller, and brake. Some nacelles are large enough for a helicopter to land on.

Pitch:

Blades are turned, or pitched, out of the wind to control the rotor speed and keep the rotor from turning in winds that are too high or too low to produce electricity.

Rotor:

The blades and the hub together are called the rotor.

Tower:

Towers are made from tubular steel (shown here), concrete, or steel lattice. Because wind speed increases with height, taller towers enable turbines to capture more energy and generate more electricity.

Wind direction:

This is an "upwind" turbine, so-called because it operates facing into the wind. Other turbines are designed to run "downwind," facing away from the wind.

Wind vane:

Measures wind direction and communicates with the yaw drive to orient the turbine properly with respect to the wind.

Yaw drive:

Upwind turbines face into the wind; the yaw drive is used to keep the rotor facing into the wind as the wind direction changes. Downwind turbines don't require a yaw drive, the wind blows the rotor downwind.

Yaw motor:

Powers the yaw drive.

Turbine Aerodynamics:

Unlike the old-fashioned Dutch windmill design, which relied mostly on the wind’s force to push the blades into motion, modern turbines use more sophisticated aerodynamic principles to capture the wind’s energy most effectively? The two primary aerodynamic forces at work in wind-turbine rotors are lift, which acts perpendicular to the direction of wind flow; and drag, which acts parallel to the direction of wind flow.Turbine blades are shaped a lot like airplane wings -- they use an airfoil design. In an airfoil, one surface of the blade is somewhat rounded, while the other is relatively flat. Lift is a pretty complex phenomenon and may in fact require a Ph.D. in math or physics to fully grasp. But in one simplified explanation of lift, when wind travels over the rounded, downwind face of the blade, it has to move faster to reach the end of the blade in time to meet the wind travelling over the flat, upwind face of the blade (facing the direction from which the wind is blowing). Since faster moving air tends to rise in the atmosphere, the downwind, curved surface ends up with a low-pressure pocket just above it. The low-pressure area sucks the blade in the downwind direction, an effect known as "lift." On the upwind side of the blade, the wind is moving slower and creating an area of higher pressure that pushes on the blade, trying to slow it down. Like in the design of an airplane wing, a high lift-to-drag ratio is essential in designing an efficient turbine blade. Turbine blades are twisted so they can always present an angle that takes advantage of the ideal lift-to-drag force ratio.

Calculation of Wind Energy :

To calculate the amount of power a turbine can actually generate from the wind, you need to know the wind speed at the turbine site and the turbine power rating. Most large turbines produce their maximum power at wind speeds around 15 meters per second (33 mph). Considering steady wind speeds, it's the diameter of the rotor that determines how much energy a turbine can generate. Keep in mind that as a rotor diameter increases the height of the tower increases as well, which means more access to faster winds.

Rotor Size and Maximum Power Output
Rotor Diameter (meters)	Power Output (kW)
10	25
17	100
27	225
33	300
40	500
44	600
48	750
54	1000
64	1500
72	2000
80	2500

Conclusion:

A typical large wind turbine can generate up to 1.8 MW of electricity or 5.2 million KWh annually, under ideal conditions -- enough to power nearly 600 households. Still, nuclear and coal power plants can produce electricity cheaper than wind turbines can. So why use wind energy? The two biggest reasons for using wind to generate electricity are the most obvious ones: Wind power is clean, and it's renewable. It doesn't release harmful gases like CO2 and nitrogen oxides into the atmosphere the way coal does and we are in no danger of running out of wind anytime soon.

But there are downsides, too. Wind turbines can't always run at 100 percent power like many other types of power plants, since wind speeds fluctuate. Wind turbines can be noisy if you live close to a wind plant, they can be hazardous to birds and bats, and in hard-packed desert areas there is a risk of land erosion if you dig up the ground to install turbines. Also, since wind is a relatively unreliable source of energy, operators of wind-power plants have to back up the system with a small amount of reliable, non-renewable energy for times when wind speeds die down. Some argue that the use of unclean energy to support the production of clean energy cancels out the benefits, but the wind industry claims that the amount of unclean energy that's necessary to maintain a steady supply of electricity in a wind system is far too small to defeat the benefits of generating wind power.