biomimicry
“ We theorized if we stuck some plants
under the panels, the in-ground and
the above-ground efforts would
both benefit.”
Thompson says that kale, cabbage, and other cool-season
crops start earlier and grow longer in the gardens. Big bush
beans, basil, sweet potatoes, and other frost-sensitive, warm-
season plants also do well, as the layout works like a heat
sink. “We don’t have hard freezes under the roof panels like
we do in our open gardens,” he says.
As these early findings are so glowing, what about possible
commercial applications of this system? Researchers are
meeting with agricultural policy economists and local growers
to better understand the barriers to wider application. One of
the negative factors might involve height from crop to top.
“If you’re doing head lettuce where the machine coming
through is 30 feet or more tall, this doesn’t work. And crops
requiring a lot of aerial pesticides present a different set of
problems,” says Barron-Gafford.
78
grow cycle
Plants under photovoltaic panels
receive less direct sunlight, but this
may lead to reduced evaporative loss
of soil moisture (white arrow), allowing
for significant water savings. Also, the
microclimate under agrivoltaic panels
may be cooler than under panels in
typical ground-mounted installations
because of this moisture release.
“The biggest scaling question involves arid areas like our
Sonoran Desert and many areas in Imperial Valley,” he
concludes. “In some cases, it’s not sustainable to continue to
grow crops there using business-as-usual methods because of
drought conditions and the amount of water needed. Many of
the formerly irrigated patches have now been solar-paneled—
converted to renewable energy—so you don’t have to have a
trade-off of one or the other. You can have both. If you’ve been
farming for generations in your area, you don’t have to give
that up. You can overlay something that will actually help
certain crops and produce power at the same time.”