Fayette school superintendent Russ Griggs has heard people express surprise about the district’s wind turbine in a couple of situations.
Some people are surprised that it doesn’t spin faster on days when the wind is blowing briskly. The answer, Griggs explains, is due to the way the system is built. A more rapid spin isn’t necessary for peak generation of electricity.
He’s also heard comments about the opposite situation—surprise to see the turbines moving in a light wind. That’s a condition that won’t be seen anymore.
It’s possible that wind at the top of the turbine is considerably stronger than what’s felt in the school parking lot, but light winds that put the blades into motion won’t have that effect now that a change was made.
“Adjustments have been made to the wind turbine for it to sleep, or idle, at low wind speeds,” Griggs explained.
The turbine was set to begin working in a wind as light as seven miles an hour, but that setting was advanced to a higher speed.
“At the lower wind speeds the turbine actually uses more power than it produces to turn the blades into the slow moving winds,” Griggs said. “Electric motors turn the blades into the wind. The adjustment will make the turbine more efficient and reduce wear and tear on the components when not turning.”
When people see an idle turbine, they’re often concerned that it isn’t working correctly, Griggs said.
“Many people have commented on the times the turbine is not spinning, concerned that it is not working. The idea is to make it work better.”
If the turbine is idle during a strong wind, there are two possible causes. Either the wind speed exceeds the maximum allowed before the unit shuts itself down, or the wind is gusty and shifting direction. In the latter condition the computer system suspects a “turbulent imbalance” and shuts down.
When that happens, a text message is sent to a school maintenance staff member who will make a visual inspection of the unit. If no problem is detected, the turbine is restarted.
Griggs said total production since January is approximately 95,000 kilowatt hours or 31 percent of the electricity used at the school during the current calendar year.