Monthly Archives: September 2013

How do Wind Turbines Work, harvesting the wind to produce electricity

How do Wind Turbines WorkHow do wind turbines work might seem like a magical process when, seeing the rotors of a windmill turning gently in a breeze, you think of this motion being transformed into electricity that can be used to power homes and businesses. Yet all wind turbines work on the same principles, from the earliest wind scooping device invented thousands of years ago to the most sophisticated huge utility turbine.

Essentially, every wind energy system transforms the kinetic energy of the wind into mechanical or electrical energy. Obviously there are huge variations in size but all wind turbines work in the same way, the smallest just the same as its largest cousin. The overall configuration is identical.

How wind turbines work

Each system consists of a rotor (“blades”) which convert the wind’s energy into rotational shaft energy, a nacelle (“enclosure”) containing a drive train and a generator. So you can easily visualize how wind turbines work. The energy that moves the wind (“kinetic energy”) moves the blades. This energy in turn moves the drive train (“mechanical energy”). This energy is then turned into electricity (“electrical energy”) in the generators and then stored in batteries or transferred to home power grids or utility companies for use in the usual way.

The tower of a wind turbine is the most dominant thing you see of a wind turbine and yet it is not the main component of how wind turbines work. It is there simply to hold the rotors at a height sufficient to make optimal use of the available wind. It also holds the electronic equipment associated with transferring electricity but these could be housed anywhere if there was no tower involved.

Another visible difference which may lead to confusion as to how wind turbines work is the style of the rotors. There are two basic designs used commercially: the vertical axis or “egg beater” type which looks something like the top sails of old sailing clippers, and the horizontal axis or “propeller” type. These modern windmills look a lot different from the old water-mill type of turbine. They look more like airplane propellers. Most of the utility scale turbines in the market today are the horizontal type.

There is also experimentation under way to use other types of rotors. For instance, a Hong Kong company is producing electricity from a wind turbines the rotors of which are a string of little “propeller wheels” mounted on a rooftop. These look like children’s party windmills in little circles, all joined together. Although the shape is innovative, the underlying principles concerning wind generation is exactly the same.

When asking how do wind turbines work and receiving this simple explanation it is hard to imagine why they are not less expensive

The good news is that due to how wind turbines work there are great opportunities to make them cheaper once critical mass is reached and more people opt for wind power generated electricity. Mass production will bring down costs. But at the moment the material and installation costs are making them prohibitive to the average consumer who paradoxically needs cheap electricity the most. More info here

Residential Wind Turbines, the future of affordable home energy

Residential Wind TurbinesWith billions upon billions of individual homes in the world, each of them with a roof or a little patch of yard, residential wind turbines are going to be where the demand is and where fortunes are to be made.

Of course there are small home turbines already in existence but the costs of installation and their general effectiveness are still holding back this form of energy from becoming a conventional power source.

Most of the technological improvements have been to the large turbines (some of them 500 ft tall) used on wind farms. They are so thermodynamically advanced today that their rotors do not even turn at high speed, which is dangerous to bird life, and they require relatively little maintenance. Residential home turbines are not quite as developed.t is extraordinary that there are relatively few residential wind turbines in the windy desert cities of the world. People who live there are throwing away the opportunity to get free, clean, renewable power for as long as the wind blows.

This form of energy generation is still far from common in the world, even in the three top wind-power producing countries: the United States, Germany and Spain. However, now that the oil supplies of the world are on the decline and because coal-fed power generators and nuclear reactors producing electricity have become unpopular with the general public, the wind power era is upon us at individual house level, not just huge wind farms that produce electricity for utilities.

There are two types of residential wind turbines available for energy generation

The first is the roof-mounted type which is really the model suitable only for DIY enthusiasts. There are so many variables in roof-mounted types (angle of roof, wind flow according to position of roof, height of roof) that their effectiveness is patchy and tends to be only as good as the innovativeness of the person who installs it. It is not a failsafe energy source for the average home owner. The residential wind turbine generating at least 10kW per day is closer to the mark. These are usually the horizontal or “propeller” type with two rotors with diameters 20 feet or less and a tower that’s not taller than 100 ft. These towers stand near to the house, positioned for maximum wind exposure. A 10kW wind turbine can generate about 10 000 kWh annually in places where the wind-speeds average 12 miles per hour. That’s enough electricity to power a typical household

You may be asking at this point why it is that residential wind turbines are not as common as satellite dishes. Well, there are few obstacles to overcome before they become the conventional way to generate home power. Firstly, their cost and installation is still too high. Paradoxically, greater demand will bring down the prices, but the costs will only diminish once the demand makes that possible. Secondly, not many homes are geared to accept wind power energy, so there are those adaptation costs too. Thirdly, the perception is that wind power is not reliable and that you could be stuck without electricity if the wind drops. In fact that is not such a great risk if the turbine is positioned correctly, but that is the perception. Then there are the aesthetic considerations.

Some people regard any windmill as an eyesore and say they are noisy and a danger to bird life. In fact these arguments don’t hold much water but the perception still remains. It will probably take celebrities installing beautiful multi-colored residential wind turbines for a negligible cost to persuade the world to take at step to the windward side.