WindTronics low speed 0,8 km / h gearless wind turbine

[hic]

Hello

(WindTronics BTPS 6500 wind turbine: A technological breakthrough in the world of residential wind power
** http://www.smartplanet.fr/smart-technol ... ateur-665/ **)

The small wind circle had been waiting for him for a long time. WT6500, the wind generator of the American WindTronics, was launched across the Atlantic in November 2010. This turbine is installed on the roof and was designed to start in light winds.

The small WT6500 wind turbine has been awaited for many months. Its manufacturer Windtronics announced its launch across the Atlantic in November 2010. This machine is installed on the roofs of homes. Its advantage: it starts with light winds, from 3 km / h. Another peculiarity: it does not contain a gear multiplier, its turbine itself serving as an electric generator. In France, the Windtronics wind turbine is offered in particular by Mercinat (official importer of the brand for France and Belgium) and Windeo.

The wind turbine on a house

The design of the wind turbine was born from an observation. In the United States, according to the National Wind Technology Center, the winds blow at a speed less than 16 km / h over more than 80% of the American residential sector, and that 90% of the time. Traditional wind turbines fitted with a gearbox (gearbox) require a wind speed of at least 12 km / h to start producing energy. An essential force to overcome the resistance of the gears.

Armed with this data, Imad Mahawili, a chemical engineer by training and a longtime wind energy consultant, focused his research on a turbine capable of exploiting very light breezes. The result is called WT6500 Wind Turbine or Honeywell Wind Turbine. "Windtronics has obtained the exploitation rights for the Honeywell brand (Editor's note: the famous manufacturer of turbo-jets for civil and military aviation)", explains Sarah Jenan, pre-sales director at Windtronics, a private manufacturer holding patents relating to the wind generator.

Energy production starts with a wind speed of 3 km / h

With a diameter of less than 2 meters, the machine weighs 77 kg. It can be installed at the end of a pole or on the roof of a house (in 2008, a hundred wind turbines camped on the top of a roof, or about 1% of the American market which totaled 10.500 small wind turbines installed). It takes the form of a wheel made up of 20 interchangeable blades. These converge in the center of the wheel towards a hub containing a ball bearing. While at their end are applied magnets, which, "in contact" with the stator (the fixed part of the wheel) containing copper, generate electricity.

Windtronics has chosen the name “Blade Tip Power System” (BTPS) to qualify its technology. With BTPS, "we end up in a way with a conventional turbine which would be turned upside down: the turbine itself becomes the electric generator", sums up Sarah Jenan. WT6500 begins to produce energy at wind speeds of 3 km / h, and will withstand air blows of speeds up to 67 km / h. The manufacturer announces a production capacity of 2.000 kWh / year, or 18% of the consumption of an average American household (source Windtronics).

An installation cost of 3.000 to 4.000 dollars

The wind turbine is displayed at a price of $ 5.999 at ACE, a chain of DIY and American decoration stores. This price includes the turbine, as well as a control box, called Smart Box, which notably includes a charge controller for the batteries and an inverter that converts direct current into alternating current. "We estimate that the installation (mounting of the turbine on the roof, battery pack, electrical connection) will cost between 3.000 and 4.000 dollars," says Sarah Jenan.

Windtronics' wind turbine assembly site (headquartered in Michigan, Muskegon, US side) is located in Windsor, Ontario, Canada. And for good reason, Premier McGuinty's province, convinced of the economic leverage role that green energies will play in the long term, has granted $ 2,7 million in assistance to attract the manufacturer's plant to its territory. An investment (Windtronics also incurred an expenditure of $ 2,7 million) which should result in the creation of nearly 200 jobs by 2012.

to suppress braking of the gear
and have good performance at low speed,

is to put the magnets of the generator on the ends of the blades


as soon as the magnets at the ends,
move at a speed of 2 to 3 m / S
the performance of the dynamo is reasonable


I dreamed of it, we made it
(but the importance of the braking of the gear in the performance escaped me, otherwise I would have been stronger )

[dedeleco]

(a good performance of a dynamo occurs when the displacement of the magnet is 2 to 3 m / S)

the law of induction does not fix an optimum, a priori, the higher the speed, and the more the coil has turns, the higher the tension, without limit,
http://fr.wikipedia.org/wiki/Induction_ ... C3%A9tique
but the dimensions and properties of the coils and magnets (surface, number of turns and resistance) set a minimum speed for a voltage.
We can have a very low speed, and a good tension, if the coils have a large number of turns and the output is set by the overall size of the coils and magnets.
The m / s is quite arbitrary.
The larger the coil, with all of its copper undergoing the variation of the magnetic field to its maximum, the higher the power obtained, thanks to the minimum possible coil resistance.
This fixes the size of the coils roughly close to the size of the magnets roughly, to have the magnetic field at the maximum which decreases quickly away from the magnets (like the reverse of the cube of the distance to the magnet).
At low speed, the power obtained is very low.
To have a constant voltage at roughly empty, you need a constant speed, or else use a number of turns which decreases with speed, or move the coils of the magnets which rotate a little, with a yield which decreases in this case.
For example mounting the magnets on leaf springs which spread them a little with the centrifugal force of the coils can allow the tension to be roughly regulated, if the springs are properly adjusted.

But you need a very nice collection of powerful magnets and coils all around which increase the price !!
$ 6000 for 1000 to 2000KWh per year, useful on site without electricity, because otherwise not amortized over the life of the wind turbine currently.

We must be able to use fewer magnets on a smaller diameter than the periphery for a much lower price with a wheel like that of a bicycle with simple blades, of variable inclination with the distance to the axis.

[Forhorse]

I don't see the interest ...
Anyway below a certain wind speed (the professionals will specify) there is almost no energy to recover.
If it is to buy an overpriced wind turbine that will come out at best a few small watts in case of a light breeze, as much put much cheaper in a more conventional wind turbine (there is no gear either in mine ...) and which will pay for itself much faster.

[Obelix]

Hello,

Here is a wind turbine which "stands" correctly from a technical point of view.
Its design is pleasant and its performance correct. Its overall yield is around 30%.
For the curves see: http://www.earthtronics.com/pdf2/Energy ... 3-2011.pdf

As Forhorse says at low wind speed there is not much to recover, the speed of 5 m / s is usually the one that starts to deliver "odds and ends" => 75 W / m² sweeping in the wind.
For information, the wind turbine delivers 100 W at these wind speeds. Below it becomes even more ridiculous ....

Obelix