Mountain View, CA 94040 Ph. (650) 814-5177 Taktron Energy Systems email
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Wind Energy

Wind power has been in use for thousands of years! Starting with early sails and windmills to grind grain and pump water, it has progressed now to on of the most economic ways to generate electricity. (Wind generators qualify for energy rebates!)

As a standalone system or in conjunction with other energy sources, it is quiet, renewable, and cost effective. Wind is often available when the sun is not shining, so it can be a good complement to solar energy systems as well. As wind often blows in the morning and evening, it can provide power at times when it is needed the most. Most systems include battery backup to equalize load demands.

Taktron Energy Systems carries the South West Wind Power line of wind generators, tools, towers, and controllers.

SWWP Air403 Wind Generators & Towers

SWWP Whisper Wind Generators & Towers

Universal System Controller
To bring everything together, we carry the EZ-Wire System Center. This unit monitors all components such as the wind generator, batteries, loads, solar panels, etc. as well as being a wiring center. Voltage, current and battery charging are all coordinated and displayed on the 6 function LED display.Controls up to 40 amps from the solar modules, 80 for the Whisper 175.

• battery charge in percent(%)
• battery voltage
• battery amps
• wind amps
• solar amps
• load amps

Is your site a good wind generator candidate?:

#1 requirement - Wind! Most areas have wind for a portion of the day - a good site has wind most of the time!

• Average wind speed of nine miles per hour (mph) or more at the location of the wind generator
• Combo wind/solar, cost effective power may happen during only a portion of the year. (Winter usually has more wind, summer more Sun)
• Power goes up by the cube of the wind speed. Twice the wind speed = 8 x the power!
• Maximum power is usually designed for 30mph. (from the above, at 15mph, that is only 1/8 of the design power)
• Recommended mounting is at least 20 feet higher than surrounding obstacles within 300 feet to avoid turbulence.

OK, so how do I measure the wind speed?

A number of methods may be used, including visual effects from the table below.

Estimating wind speed from visual effects
Pink = No Wind Power Potential Yellow = Some Potential for Wind Power Green = Good Wind Power Potential
Wind Speed (MPH)	Wind Effect
0-1	No drift on smoke rising up
2-3	Smoke drifts slightly
4-7	Wind felt on face; leaves rustle; flags move slightly
8-12	Light flag flutters gently; Tree leaves and twigs move
13-18	Small tree branches move, flags flutter; Loose paper and dust moved about
19-24	Small trees and bushes sway; flags flap vigorously
25-31	Large branches of trees move. Audible whistle from power lines.
32-38	Large trees move; Flags straight out
38 +	precautions of high wind must be considered

Taktron Energy Systems also carries the NRG Wind Totalizer. This instrument keeps track of wind over a period of time, much like your utility meter. Wind speed averages may be easily calculated by dividing the 'wind miles' by hours it has been running. If the unit is installed and checked regularly, (weekly/monthly) a very good wind analysis of the site would allow accurate prediction of power available. (1-2 years of data is best). Some data may also be available from local weather stations, farmers, etc.

Other instruments availble for wind spead measurement are the Dwyer and Kestrel wind speed indicators. They measure instantaneous speed, but do not record the data. Both instruments can be tower-mounted for good speed analysis

Height vs. wind speed
Feet above ground level	30	120
Wind speed increase above ground level	1.5 x	2 x
Power increase from ground level	3 x	6 x

Wind Generator Towers:

Freestanding tower or Pole? Wire guyed for stability? Generally it isn't recommended to mount towers onto roofs (potential roof damage, and noise), but rather directly onto the ground. Any wind installation must be carefully engineered for safety. Usually this involves a large concrete base for a pole or concrete pads for towers. It is not a task to be taken lightly, as the wind loads need to be calculated carefully.

Pole mounted:

• Large concrete base
• Minimum space requirement
• Tilt-up is most economical and easiest to install (prewired/mounted prior to tower erection eliminates climbing)
• 4-5 inch steel tubing can be purchased locally to reduce freight charges

Guyed Tower:

• Steel truss tower
• Most cost effective
• Most ground space (especially with guy wires)

Wire Size:

As with all energy systems, the maximum return on investment from power will be available by minimizing the voltage drop from the generator to the controller/battery. Typically ~2% drop is optimum for wire cost vs. losses. With the DC output of AIR403, you can refer to common DC wire tables. The Whisper wind generator uses 3 phase AC that is rectified at the controller, and allow a smaller wire size. (wire size is 1/2 the rated load, but you need 3 for the 3 phases). If wire size/pricing is an issue and particularily for longer runs, the price of Whisper HVLV (240VAC) output may be attractive and even lower overall.