When a new solar array is proposed, it’s common for neighbors to push back. Sometimes their opposition is simple NIMBYism or maybe political posturing. And sometimes, it’s a legitimate concern, especially when the worry is that farmland will be lost.
This is where the opportunity for agrivoltaics comes into play.
Agrivoltaics. I swear I didn’t make it up. It’s a funny word for a simple idea: the simultaneous use of land for solar power and agricultural production.
When it’s done right, solar panels are elevated above the land allowing for agricultural uses beneath them. The solar panels create microclimates in their shade that do not preclude, and can even benefit, agricultural activities.
What are microclimates? They are the extremely localized environmental conditions provided to a space – sometimes only inches between two spaces.
Solar arrays create these conditions by casting shadows on the land, keeping areas cooler or more moist. Solar panels redirect rainwater, dew and snow, making some areas a little wetter and others drier. They reflect heat radiated from the earth at night, making the ambient air temperature a little bit warmer on cold fall nights.
The solar array structure itself can dampen strong or desiccating winds on the land beneath them. This means that between the rows of solar panels, every inch, row-to-row, has a slightly different microclimate. I liken solar arrays to forest canopies giving dappled light to the land beneath.
With hotter and drier summers here in the West, a little more shade can help. I first realized the shade’s potential years ago on my farm when I saw that the thickest grass on my hay pasture received afternoon shade from an elm tree.
Many of the crops we grow in Colorado are non-native, from our leafy greens to root crops to our grasses for hay — brome, alfalfa, timothy, and orchard grasses all come from overseas. Most non-native crops would prefer a different climate over our bright and dry 14-hour summer days. A single-axis tracking solar array, where the panels follow the sun east to west, will move shade across the land beneath it so that no spot gets full sun or full shade. This reduces direct sunlight by 25-50% in the spaces between the rows of panels. Such shade creates microclimates that more closely mimics the native habitats of some of our favored vegetables and cash crops.
I know this because I live a few hundred feet from my family’s 1.2-megawatt, single-axis tracking solar array covering 4 acres of our farm. Our solar array is called Jack’s Solar Garden. We collaborate with the National Renewable Energy Laboratory, Colorado State University, and the University of Arizona to study these microclimates and how vegetation responds to them.
Leave a Reply