There are thousands of turbines in the California desert. Their job is to generate and dispatch clean power.
One of the green energy giants growing in size and output is the San Gorgonio wind farm. But it’s bringing changes to the local climate along with its growth.
The land under the blades started behaving erratically.
Suddenly, the turbines weren’t just harvesting the wind anymore. The actual physics of the environment were shifting.
How did the farm end up changing the climate so drastically?
How turbines are linked to localized climate shifts
The conditions in the San Gorgonio Pass are as fierce as you’d expect from a desert. The thousands of turbines in the area are designed to last through the incredible heat and the Californian winds.
It took some marvelous engineering to install such an expansive presence under such intense conditions.
The volume of clean electricity generated by the new-age energy technology is impressive.
And it’s all done on land that would be used for nothing otherwise.
But there are consequences to this immense generation activity.
Researchers started picking up subtle anomalies as the maze of turbines grew denser. Precision weather instruments detected microclimate shifts. But only around the spinning rotors.
Then the ground below the blades started behaving in new ways. And it wasn’t simply down to a natural regional climate trend.
Something man-made and immediate was changing the weather—an inadvertent effect of harvesting it.
The mechanism behind the shift wasn’t all that easy for scientists to figure out. What goes on when thousands of enormous rotors spin simultaneously?
Cool days and hot nights
The anomaly in the San Gorgonio stats was obvious at a glance.
Two distinct, conflicting trends were picked up by meteorological sensors.
Near-surface temperatures dropped during the blistering hot days. Beneath the massive turbines, the ground was markedly cooler than the open desert nearby.
The system flipped at night. Normally, the air would cool rapidly as soon as the sun sets. Instead, it remained stubbornly warm with elevated temperatures throughout the dark hours.
This was a complete inversion of typical desert climate behavior.
And the fluctuations were strictly local, according to the study “Impacts of Wind Farms on land surface temperature,” published by Nature Climate Change in ResearchGate.
The phenomenon could not be put down to global warming, seeing as the disruptions were immediate. What was it about the motion of the blades that flipped the thermometer?
Wake mixing: What we couldn’t predict
The answer is a phenomenon called “wake mixing” that has to do with the atmospheric boundary layer.
The spinning blades mix the layers above the ground.
The rapid cooling of the desert floor at night means a thin layer of cold air is normally trapped at the surface. A warmer layer of air is left directly above.
The blades chop right through the two layers of the atmosphere.
The rotors physically drag the warm upper air down to the surface. This prevents the ground from cooling like it normally would.
During the day, it’s the reverse.
The physical structures block and reflect some of the incoming solar radiation. But the blades continue to mix the air.
This creates a localized canopy effect, shielding the ground from daytime heat at its peak.
It’s not bad news, say meteorologists
This temperature swapping is not an environmental disaster. But it is definitely a fascinating look at the footprint of human engineering.
When we harvest natural forces on such a major scale, we automatically change the environment.
Is clean energy infrastructure really capable of permanently altering the climates of the landscapes we choose? And are we prepared for the consequences?