# Factors to Consider

The effect gathered from the wind depends on several things. The following things are to be considered:

• A big blade needs a big base structure and vice versa. If the wind speed doubles the effect is increased eight times. With a well built turbine one can get 30-40 percent of the wind’s energy. This means that the wind velocity has been decreased by 1/3. Wind velocity is of great importance. The energy that one can gather from the wind increases by the velocity of the wind measured in cubic.

Shape on the Blade (fast runner or other)

• The blade needs to be constructed in special ways depending upon how much of the wind one wants to catch. The blade has to work with the wind. The force has to be equalized or the blade wing would work against itself and could brake too easily. Different shapes have their own specific parameters to be considered. First determine how large a blade you want, then make the blueprint by plotting out the wing cm by cm. I’ve included the parameters on the wing profile page.

Type of Generator (2-15 kW or more)

• Magnetic braking or automatic resistance? If the wind gets to high then the turbine could be automatically braked to stop it from rotating or one can manually pull it down to the ground until the wind has decreased.
• Is the generator by itself or is the turbine integrated with the generator? Some constructions work better to using 5 meter/s and others work better at 20 meters/s.
• What kind of gearbox do you want? This is dependent upon how large or small the turbine is and how much energy you want to produce.
• Do you want a steady flow at 230 watts AC? Then you need to have a generator that can make 3000 rpm (revolutions per minute), which is needed to get a sinus wave at 50 hertz (this is to generate the magnetic fields in AC). That’s normal in Sweden anyway. You could get more or less out of the turbine by choosing the right generator, gearbox and number of revolutions.

Transformer / Regulator (what kind of energy do you want?)

• Direct current (DC) or alternating current (AC)? AC generates magnetic fields that is needed for many (or most) electrical devices like TV’s and the like. DC can be used if you only want to have a couple of light bulbs running. There are many machines like electrical heaters that can use DC, and if not, they can be converted with some minor mechanical skill.
• Are you going to use a water heater? One can direct the motion energy from the turbine into some kind of a water tank to generate heat by friction. This heat can be directed to a water heater via pipes and other elements. Heat directing can be done without water as well by directing the friction energy or heat in a rubble of stones.
• Store the energy; how? DC can be stored with batteries, but AC can’t. If you want to have AC then you need to have a generator that can produce it. If you want to store the energy, then you need a charger that can regulate the energy going into storage. There is always some energy loss within such a system.

Offered by Geson.