Best Management Practices for Wind Machines

By Hugh Fraser (Former OMAFA)

Wind machines have been shown to provide crop protection during extreme cold weather. However, some neighbours may be disturbed by the noise produced.

 Here are some neighbourly Best Management Practices for wind machine operation:

• Use the most up-to-date plant hardiness information and take into account critical plant temperatures when decisions are made to operate a wind machine. This data can be found on the egrape system.
• Use the best local weather forecasts available, so wind machines are only used when necessary.
• Do not include “wind chill” when determining the start temperatures for wind machines. Plants are not affected by windchill.
• Do not operate wind machines if wind speeds are much higher than 7 km/h as there is unlikely to be a strong temperature inversion or warmer air above the field anyway. Wind speeds that are 13 km/h or higher, can damage the blades of wind machines. Never operate wind machines if wind speeds are 21 km/h or higher, as this can seriously damage them.
• Monitor continually for strong temperature inversions, greater than 3˚C, on or near the farm to determine if operating machine(s) might provide some plant protection from cold injury. This includes a tower at least 10 m high to monitor air temperatures above the crop.
• Set start-up temperatures for wind machines based on sensors located below the fruiting wire and within 15 m of each machine.
• Monitor and automate start up/operation/shut down of wind machines, using a combination of real-time remote air temperature/wind speed/wind machine operation sensing devices and monitoring via cellphones/computers/pagers, etc.
• Set the differential (wind machine stop temperature) 2°C–3°C higher on wind machines than for start-up temperatures.

To avoid noise complaints:

• Explain to neighbours living within 125 m of a machine how and why wind machines operate, consider providing a copy of OMAFRA factsheet (listed below).
• Consider creating an early warning system to remind neighbours about possible wind machine use. Give neighbours a 24 hour cellphone number to call.
• Set machines closest to the neighbours to be the last on and the first off.
• Be diligent operating wind machines on farms where you do not live, as you are not always there to hear if and how they operate.

For more information on Wind Machine operation and Best Management Practices please contact your wind machine distributor and OMAFRA Factsheet Wind Machines for Minimizing Cold Injury to Horticultural Crops, H. Fraser, June 2010