Wind energy

We’ve used the wind as an energy source for a long time…

The Babylonians and Chinese were using wind power to pump water for irrigating crops 4,000 years ago, and sailing boats were around long before that.

Wind power was used in the Middle Ages, in Europe, to grind corn, which is where the term “windmill” comes from.

The kinetic energy of wind is also a source of energy and can be converted into mechanical energy and electricity. A sailboat uses wind energy to move through the water. This is a way to produce power through wind.

How it works:

The Sun heats our atmosphere unevenly, so some patches become warmer than others. These warm patches of air rise, other air blows in to replace them – and we feel a wind blowing. We can use the energy in the wind by building a tall tower, with a large propellor on the top. The wind blows the propellor round, which turns a generator to produce electricity.

We tend to build many of these towers together, to make a “wind farm” and produce more electricity.

The more towers, the more wind, and the larger the propellors, the more electricity we can make.

It’s only worth building wind farms in places that have strong, steady winds, although boats and caravans increasingly have small wind generators to help keep their batteries charged.

Operation of a turbine

The operation of a turbine is much simpler than many people think. So what happens is that the strong wind can turn the blades of a turbine adapted to the wind (instead of steam or water is the wind that turns the turbine). The turbine fan is connected to a central axis which contains over a rotating spindle. This axis comes to a transmission box where the speed is increased. The generator connected to the transmitter produces electricity. The turbine has a system slowdown in case the wind becomes too strong, thus preventing too rapid rotation of the fan.

If still have doubts you can analyze the picture below 😉

More

The best places for wind farms are in coastal areas, at the tops of rounded hills, open plains and gaps in mountains – places where the wind is strong and reliable. Some are offshore.

To be worthwhile, you need an average wind speed of around 25 km/h. Most wind farms in the UK are in Cornwall or Wales.

Isolated places such as farms may have their own wind generators. In California, several “wind farms” supply electricity to homes around Los Angeles.

The propellors are large, to extract energy from the largest possible volume of air. The blades can be angled to “fine” or “coarse” pitch, to cope with varying wind speeds, and the generator and propellor can turn to face the wind wherever it comes from. Some designs use vertical turbines, which don’t need to be turned to face the wind.

The towers are tall, to get the propellors as high as possible, up to where the wind is stronger. This means that the land beneath can still be used for farming.

For more information visit the page of wind power.

Advantages

• Each turbine produces between 50 to 300 kilowatts of electricity that could light 3000 lamps of 100 watts;
• The wind farms are compatible with other land uses (agriculture and livestock in particular);
• Job creation;
• Generation of investment in disadvantaged areas;
• Financial benefits (owners sell the land for a much higher price);
• The turbines required little maintenance.

Disadvantages

• The wind does not blow with intensity throughout the year and there are always areas with a very low intensity of wind (the wind have to reach a speed exceeding 20 km / hour to spin the turbine fast enough);
• Impact on the landscape;
• Occupation of natural reserves;
• Can be overcome with the fuel cells (H2) or the technique of pumping water;
• Noise pollution (the wind hitting the blades make a constant noise so the houses have to be about 200 m).