Tuesday, 22 July 2014

All About Wind Energy


Wind Energy is energy that is created by using the wind to generate power normally by means of windmills or wind turbines. This useful form of energy makes electricity.

Wind energy is a clean, abundant renewable source of energy and also the fastest growing source of electricity generation in the world today.

Wind Energy is not a modern technology but in fact it has been around for over 4000 years. The Babylonians and Chinese were using wind power to pump water for irrigating crops 4000 years ago and before that sailing boats had long been around. It was also used in the Middle Ages in Europe to grind corn which is where the term "windmill" originated from.

Wind Turbines
Wind turbines produce electricity by using the natural power of the wind to drive a generator.
How this works is all to do with the way the sun heats our atmosphere. Our atmosphere is uneven which means some patches become warmer than others. The warmer patches of air rise and other air blows to replace them which creates a wind blowing.

The energy in the wind can be used to generate electricity. This is done by building a tall tower with a large propeller on the top known as a wind turbine, the wind blows the propeller around which then creates electricity. There are normally many Wind Turbines built close together to make a wind farm (see below) which produces more electricity. The more Wind Turbines, the more electricity can be made.

The development of wind energy technology is developing fast, and turbines are becoming cheaper and more powerful, which in turn is bringing the cost down of renewable generated electricity.

Wind Turbines are the most modern of wind machines and can be useful for charging batteries, pumping water and powering homes.

How do Wind Turbines Work?
A Wind Turbine converts kinetic energy in the wind to electrical energy and distributes it around the country.

1. The wind blows onto the wind turbine blades which makes them turn and catches the wind
2. The blades turn a shaft inside the nacelle (this is a box at the top of the turbine)
3. The shaft inside the gearbox increases the rotation’s speed
4. The generator uses magnetic fields to convert rotational energy into electrical energy. (Similar to those found in normal power stations)
5. The power output then goes into a transformer to convert the outgoing electricity at around 700 Volts to the correct voltage for distribution system, typically 33,000 Volts.
6. The national grid then transmits the power around the country
7. The stronger the wind, the more electricity is produced

Wind Farms
Wind power plants more commonly known as Wind Farms; consist of large groups of Wind Turbines that use a common power provider to produce electricity. They are all interconnected and are all controlled and operated by computerised monitoring systems.
Wind Farms are best located where the wind is strong; you will normally find Wind Farms in coastal areas, open plains, tops of rounded plains and gaps in mountains
There has been a large increase of Wind Farm Contractors UK in recent years.

The need for clean Energy
The more conventional methods of generating electricity consist of burning fuel to provide energy to drive generators. These technologies use fossil fuels, coal, oil, gas or nuclear fuel. Fossil fuels create pollution which contributes to global climate change.

Although this source of electricity generation dominates the energy needs for Europe, renewable energy sources currently provide 5.4% of the European Unions primary energy needs, but it has the potential to provide much more.

Wind Energy in the UK
40% of all the wind energy in Europe blows over the UK, making it an ideal country for further development into wind power.

There has been a huge increase in the construction of wind energy schemes UK in recent years, and with its many benefits of more conventional energy sources this should continue to grow well into the future.

Cost of Wind Turbines
The effective cost of wind turbines continues to drop; the cost per kilowatt-hour has dropped, for big US wind farms, from $1 per kilowatt-hour to $0.25 per kilowatt-hour. It is very difficult to compare wind farms to natural gas driven wind farms.

It is also difficult to compare the capacity of large wind farms to the capacity of fossil fuel power plants, as wind energy is dependent on how much wind there is. This can be affected by many different factors, such as location and the time of year.

Development
Wind turbines are manufactured in a range of vertical and horizontal axis types. Small turbines are used for applications such as battery charging or auxiliary power on sailing boats. Large grid connected arrays of turbines are becoming an increasingly used source of power in the commercial sector.
There are some concerns over the efficiency of wind turbines, but their ability to produce green power has seen the development of the technology to be very successful.

Types
Types of Wind Turbines
There are two types of wind turbine, Horizontal Axis Wind Turbines (HAWT) and Vertical Axis Wind Turbines (VAWT).

Horizontal Axis Wind Turbines have the main rotor shaft and electrical generator at the top of the tower and must be directed into the wind. Most HAWTs have a gearbox which turns the slow rotation of the blades into a quick rotation that is more suitable to drive an electrical generator.

Vertical Axis Wind Turbines have the main rotor shaft situated vertically. Key advantages of the design are that the turbine does not need to be pointed directly into the wind to be effective; this is an advantage where the direct of the wind is variable day to day. These types of wind turbines can be favourable when mounting onto buildings.

VAWTs are less efficient as they have a low rotational speed, resulting in higher torque. With a Vertical Axis Wind Turbine the generator and gearbox can be placed near the ground, using a direct drive from the rotor assembly to the ground based gearbox, improving access for maintenance.

Wind Turbines Today
The modern Wind Turbines of today have a maximum capacity of around 2 megawatts (2000 kilowatts), based on per hour at full capacity of electrical production.


A 2 megawatt wind device generates enough power for around 1100 homes, working only at around 30% capacity. Most wind turbines based on coastal areas run at least 80 percent of the time, but not at full capacity. Currently new studies are being done by many universities, with new developments in turbine blade design and more efficient generator designs, the effectiveness increases. New designs are also being developed for horizontal and new vortex type wind generators.

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