Your Questions About Wind Turbine

adminsta answers:

Http://peswiki.com/index.php/Directory:Home_Generation:Wind_Turbine

There is one. I’ll try more.

adminsta answers:

You can make a scaled down wind turbine. However the power decrease is not linear, its squared. A small turbine hardly makes any power at all. That is why you have to get big to be effective.

adminsta answers:

A wind turbine or wind generator or windmill uses the energy in moving air (wind) and converts it into usable electrical power with a generator. The force of the wind hits the blades of the windmill causing them to rotate. This rotational force turns a generator inside the wind turbine. Magnets in the generator cause and electrical current to flow. This electrical current flow is used to power things.

adminsta answers:

It’s not quite that simple.

Wind turbines have a ‘power curve’ showing their output at various wind speeds. An ‘average’ can be based on minor variations (7.2 to 7.6 m/s) or major variations (3 to 12 m/s – OK, that averages to 7.5, but you get the point). Since the energy in wind varies with the cube (third power) of the wind speed, the amount of variation in the average is critical.

There is a calculator here: http://www.windpower.org/en/tour/wres/pow/index.htm, but I highly recommend you review the other information on the site before spending any money!

Best of luck!

adminsta answers:

As can be seen from the power curves in the first link, there is nothing till about 12km/h wind, then only a small fraction of the maximum power which is reached at around 28km/h. It is important to undertake a proper survey, as wind shear can have a large influence. The Vestas site has advice about planning, but not much detail. Send them an email.

In this kind of situation, with no grid to fall back on, it is usual to have diesel generators running to smooth the load. These are special “low load” types (see the 6th link below). They run on no load when the wind is there, synchronised with the wind generators.

I should warn you that it is easy to convince yourself that a wind system is ok when it isn’t, because you want it to be true. There are all sorts of considerations. It may make sense to have oversized turbines so you still get enough power despite bad wind. What happens when no-one is using power? One or two big ones or lots of smaller ones? You need the turbine manufacturer and/or experienced consultants to help make these decisions with a proper site appraisal. If the trees are all horizontal that is a good start. It should definitely be what most people would think is a windy place, and with steady winds. Solar panels are easier to engineer, perhaps lower risk, but it does depend on where you are too. No clouds in that case. It is not uncommon to have them together, with the low load diesels.

You probably already know the peak power demands from existing power supplies. You should try to factor in for 25 years growth of island power usage too. The figure varies, especially because or airconditioning/heating situation. One could say a typical is 4kWh per house per day. You have to consider community buildings too. This figure takes no account of peak demand anyway. It tells you how much fuel you need for diesel generators.

Vestas is a Danish pioneer in larger wind systems, with some innovative features.
The first link shows power versus wind speed.
The second link also has these for the latest models, look for the brochures. It also gives advice about
The third link has a list of other manufacturers.
The 4th and 5th links have pictures of wind farms with some details that could be helpful for contacts.
The sixth link is about low load diesels.

adminsta answers:

You dint tell what is the turbine’s output voltage and what of the battery’s. What is happening in ur circuit is that the current from the battery is flowing back to the turbine & driving it as a motor.

I will suggest putting a diode in series with the turbine-battery circuit, so the current cant flow back. Connect the +ve terminal of diode to the +ve terminal of the turbine (i.e. When it’s producing energy) & the -ve of the diode to the +ve of battery. Then the turbine wont rotate because of the battery. But when the turbine’s voltage will be > that of the battery’s while rotating, the battery will get charged.

Note that the turbine’s voltage must be > {battery’s voltage + diode’s fwd voltage drop (0.7V) } in order to get the battery charged. I will also suggest to put a suitable resistor (5-10 ohms) in series with diode so as to limit the charging current to the battery.
Hope that will help