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Wind Energy,All you need to know!

With ever increasing standards of living, comes an ever increasing demand for power by an ever-increasing population of irresponsible nitwits on the planet. And as you all know: with great power, comes great responsibility. Terrible puns aside, today we have faced with a problem that has been looming over our heads for decades and which can no longer be solved by procrastination. Judgement day is here and we are all on trial for the almost uncalled for burden we put on the Earth’s resources. Human beings, like most of the nature, has an inherent lust for the path of least resistance and a very curious affinity for pollution. So far, that has been setting the readily available renewable resources ablaze and thriving on the sweet goodness that comes out of it. But the curtain has closed on this magnificent gift and hence, we must look elsewhere. And this is where wind energy has come in.

One of the front-runners of the renewable energy march is wind. Wind power is the use of air flow through wind turbines to mechanically power generators for electric power. Wind power, as an alternative to burning fossil fuels, is plentiful, renewable, widely distributed, clean, produces no greenhouse gas emissions during operation, consumes no water, and uses the little land. The net effects on the environment are far less problematic than those of non-renewable power sources.

Since wind speeds vary a lot over the year and even on any given day, it is not feasible to power the entire grid using just wind energy. It is therefore used in conjunction with other electric power sources to give a reliable power supply. A wind farm is a group of wind turbines in the same location used for the production of electric power. A large wind farm may consist of several hundred individual wind turbines distributed over an extended area, but the land between the turbines may be used for agricultural or other purposes. For example, Gansu Wind Farm, the largest wind farm in the world, has several thousand turbines. A wind farm may also be located offshore.

Almost all large wind turbines have the same design — a horizontal axis wind turbine having an upwind rotor with three blades, attached to a nacelle on top of a tall tubular tower.

In a wind farm, individual turbines are interconnected with a medium voltage (often 34.5 kV), power collection system and communications network. The kinetic energy in the wind drives the blades of the turbines which are used to drive alternators which supply power to the grid.

Wind energy has not been able to gain much traction due to high installation costs, unsteady power output and cheaper alternatives such as coal. Some critics even say it shouldn’t be implemented because it spoils the aesthetic beauty of our estates.

Granted, wind energy does have its shortcomings but this does not mean it should not be considered at all. Steady or not, it is a continuous source of power and can never run out. Worldwide there are now over two hundred thousand wind turbines operating, with a total nameplate capacity of 432 GW as of end 2015. The European Union alone passed some 100 GW nameplate capacity in September 2012, while the United States surpassed 75 GW in 2015 and China’s grid-connected capacity passed 145 GW in 2015.

World wind generation capacity more than quadrupled between 2000 and 2006, doubling about every three years. In 2010, Spain became Europe’s leading producer of wind energy, achieving 42,976 GWh. Germany held the top spot in Europe in terms of installed capacity, with a total of 27,215 MW as of 31 December 2010. In 2015 wind power constituted 15.6% of all installed power generation capacity in the EU and it generates around 11.4% of its power.

Advantages of Wind Energy

From a practical point of view, wind power is quite cost-effective and is also a clean fuel source. Wind energy does not pollute the environment unlike power plants, which primarily depend on the combustion of fossil fuels that produce harmful nitrogen oxides and sulfur dioxide, eventually causing human health problems and economic damages.

The Wind is also widely used on the domestic front, so the nation’s wind supply is plentiful and inexhaustible. If we look at the sustainability factor, it can be concluded that as long as the sun shines and the wind blows, the wind energy can be used to create power across the grid.

WIND TECHNOLOGIES

Wind energy technologies use the energy in wind for practical purposes, such as generating electricity, charging batteries, pumping water, and grinding grain. Mechanical or electrical power is created through the kinetic energy of the wind. Wind power available is proportional to the cube of its speed, which means that the power available to a wind generator increases by a factor of eight if the wind speed doubles.

 The turbine’s blades are similar to the propeller blades on an airplane. The hub of the turbine is rotated as the rotor blades generate lift from the passing wind. This rotating action then turns a generator, which creates electricity.
 When the wind blows a pocket of low-pressure air forms on the downwind side of the blade. The low-pressure air pocket then pulls the blade toward it, causing the rotor to turn. This is called lift. The force of the lift is actually much stronger than the wind’s force against the front side of the blade, which is called drag. The combination of lift and drag is what causes the rotor to spin.
 Since the wind’s speed typically increases with height above ground (due to decreasing friction with the ground), wind turbines are mounted on a tower to capture more energy. At 100 feet (30 meters) or more above ground, they can take advantage of faster and less turbulent wind.

Wind turbines are mounted on a tower to capture the most energy. At 100 feet (30 meters) or more above ground, they can take advantage of faster and less turbulent wind.

 For the best utilization of wind turbines, they should be placed where wind speeds reach 16-20 mph and are at a height of 50m. It is also important that utility-scale power plants are located near existing power lines and in the windiest sites available.
 Wind energy technologies can be used as stand-alone applications, connected to a utility power grid, or even combined with a photovoltaic system. For utility-scale sources of wind energy, turbines are usually built close together to form a wind farm that provides bulk power.
 Stand-alone turbines are typically used for water pumping or communications. However, homeowners and farmers in windy areas can also use small wind systems to generate electricity.

Wind Energy Turbines Convert Wind into Electricity

As well as using the power of the sun to heat water, living spaces or produce electricity using photovoltaic cells, we can also use the suns resource in the form of Wind Energy to generate electrical power as it is the suns solar energy that controls our weather.

The sun heat’s our planet unevenly, making the air hotter around the equator as it absorbs more energy and colder near the poles. Air expands when it is warmed and contracts when it is cooled. These differences in temperature cause convection currents to flow around the globe as the denser air from the colder regions moves to the warmer regions were the air is lighter. This movement of air within the atmosphere of the earth from a hotter place to a colder place is what we call the “wind”, and which can be weak or strong depending upon the solar energy striking the earth at that time.

Also, since both the Earth’s land mass and its oceans absorb and release solar energy back into the atmosphere at different rates, there is a constant shift of air from between the Earth’s surface and the atmosphere causing the air to move around in currents, again generating “wind energy”. The Earth’s rotation also plays a major role in wind energy production.

Then we can define wind as “air in motion” which can vary from zero to high gusts. In theory, the world has an inexhaustible supply of free wind energy as every corner of the earth receives the effects of the wind at some time during the day. Also, due to annual variations, such as winter or summer time, or geographic locations, such as flat desert or mountain ranges, some parts of the world receives more of the winds energy than others. With fossil fuel supplies running out, Wind Energy and Wind Power are now becoming an important renewable energy source.

As we now know, “wind energy” is a free and renewable secondary form of solar energy, due to the uneven distribution of temperatures in different areas around the world, and people have been harnessing this free wind energy resource since windmills and sailing boats were first used in ancient times.

Windmills harnesses the energy contained in the moving air to produce mechanical power in the form of torque which is then used directly for pumping water or grinding corn, but windmills could also be modified to generate electrical power for heating and lighting by attaching an electrical generator to the rotating shaft connected to the windmills sails.

The kinetic energy (kinetic energy is the movement or motion of substances and objects) contained in the wind can be converted into both mechanical and electrical energy by a windmill. A modern type of windmill that uses the kinetic energy of the wind to produce an electrical energy output is called a Wind Turbine.

Wind turbines that are in use today are far more likely to be a type of wind generator which operates differently and more efficiently from a conventional sail windmill. Multiple wind turbines that are arranged together in clusters to capture large amounts of wind energy at the same time and convert it into electrical power feeding this power into the electrical grid are known as Wind Farms. These wind farms can be located on flat land, mountain tops or offshore in the sea.

Wind turbine technology may look simple but there are many mechanical parts to a modern wind turbine. The wind rotates the turbines rotor blades around a central hub, which turns a low speed gearbox shaft, which rotates a generator at a higher speed and makes electricity. The electrical generator converts the kinetic energy of the rotating blades into electrical energy were electrical cables carry this energy to an electrical sub-station for distribution to the utility grid. Modern wind turbines have a number of air foil shaped rotor blades resembling aeroplane propellers, unlike windmills which usually had several flat blades or sails. A combination of both lift and drag causes the turbine blades to rotate in the wind.

Although there are many different configurations of wind turbines available today, most of them can be classified as either “vertical-axis wind turbines” (VAWTs), which have blades that rotate about a vertical axis, or “horizontal-axis wind turbines” (HAWTs), which have blades that rotate about a horizontal axis parallel to the wind. Both have their good and bad points in how they extract the wind energy but both designs can generate electricity from a few hundred watts to many thousands of watts but both types contain the same major components such as:

  • A tower or support mechanism that supports the rotors, gearbox, generator and axillary equipment.
  • The wind turbine with two or more rotor blades which captures the wind energy.
  • A Mechanical gearbox to increase the rotational speed of the generator.
  • An Electrical generator or alternator to produce the electrical power.
  • Speed sensors and control electronics to monitor and regulate the speed and output.
  • Electrical cables connecting the wind turbine to the area grid.

Conservation of Wind Energy

One of the most important benefits of wind is the fact that it is a renewable form of energy, so it can be used over and over again. A great way to conserve wind energy is by using a generator system that’s powered by wind turbines. When the wind blows against the blades, the rotor moves the shaft. After the shaft gets connected to a generator, wind energy is automatically converted into mechanical energy, which eventually helps the generator to spin. So, as the generator spins, it produces electrical power or energy.

We can also use solar panel system along with wind generators, which will eventually conserve wind energy. Solar panel systems successfully convert sunlight into usable forms with the help of photovoltaic, or solar cell, technology. Did you know that solar cells are made of a material that has the potential to generate an electric current when exposed to sunlight? This current can be put to use and power devices like a pump, an electrical grid or a heating system.

It is imperative that we funnel more research and funding into wind energy and similar sources of renewable energy. As it stands today, it does not seem feasible to use wind energy and any self-respecting investor would rather use coal or petroleum. Change is never easy and we must make note of this fact and make an attempt to perfect the way we tap into resources that would do less harm to ourselves and to all the generations to come.

Another resource of the future is solar energy. Read more about Solar Energy.

You may also like:

What is energy? Types of energy and definition

Renewable energy: The way of life for the future

Kinetic energy: All you need to know

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