Wind Turbines
A wind turbine generates power by taking energy out of fast moving air. As the turbine slows down the air the momentum is transferred from the air to a shaft of either a generator or alternator in order to generate electricity. The power that can be generated from wind is dependant mainly on air speed and the area that is swept by the turbines blades.
The electricity generated from the turbine goes through an inverter so that is the same voltage and frequency as the rest of the power in the home. The inverter is tied into the breaker panel where the electricity is then distributed through your house.
Like most things electricity will take the path of least resistance meaning that any power generated will first be used by things in your home (lights, tv, computers…) if the turbine is generating less power than what is needed to run all of the devices that you are using the additional power would come from the grid. If the turbine is producing more power than what is being used in your home the excess power leaves your house and goes back into the grid where someone else will use it.
As of January 1st 2009 (in Alberta) the excess power that you generate can be metered and you will be compensated at the same rate at which you pay for electricity. There are some regulatory requirements that have to be taken care of in order to be able to connect your wind turbine to the grid but that would be taken care of by Threshold Energies as part of the installation of your wind turbine.
There are two major classifications of wind turbines: horizontal and vertical.
- Horizontal axis wind turbines (HAWT) are the most common and are available in many sizes from 400 Watts all the way up to industrial sized turbines.
- more efficient power production
- typically mounted on tall towers where the winds are stronger
- Vertical axis wind turbines (VAWT) are just recently coming to market in large numbers. The VAWT’s are limited to the middle range of power capacities, they are typically between 1 kW and 20 kW. The advantages of VAWT’s are as follows:
- the generators and gearboxes are closer to the ground which makes maintenance easier
- they are omni-directional, meaning that they don’t need to be pointed into the wind or at least doesn’t require a yaw device to be pointed in the right direction
- can operate in slower winds
- slower rotation, which results in quieter operation, less danger for birds, and lower maintenance
- can operate in turbulent winds
