As the climate changes and droughts become more frequent, many regions are struggling to maintain healthy ecosystems and agricultural productivity but new research from Colorado State University suggests an unexpected ally in the fight against drought: solar panels.
Scientists studied how solar arrays might benefit grasslands by reducing water stress during dry years. This idea, known as the aridity mitigation potential (AMP) of solar panels, proposes that while panels create shade (which can reduce plant growth by limiting sunlight), they may also help plants conserve water by lowering temperatures and reducing evaporation from the soil.
To test this, researchers monitored plant productivity across several locations in and around a solar array over four years with varying rainfall. The key question: do solar panels help plants grow better during dry conditions?
They found that in years with below-average rainfall, areas under or near the solar panels were up to 90% more productive than nearby open grassland. On average, productivity was about 20% higher in dry years within the solar array. The benefit was especially noticeable in areas that received partial shade in the hotter afternoon hours, when plants are under the most stress from heat and dryness.
In average rainfall years, the benefit was still present, though smaller, around 12% to 28% higher productivity in shaded zones. On the other hand, during very wet years, the shade from solar panels actually reduced productivity slightly, presumably because plants had ample water and instead needed more sunlight to grow.
Cornell Postdoctoral Research Associate Matthew Sturchio, an author on the paper, said: ‘There have been several studies reporting improved plant and water relations from solar arrays, however, this is the first analysis that shows how that pattern becomes more pronounced with increasing aridity or dryness like we see in Colorado.
‘The most important takeaway here is that even though this solar array was designed to maximise energy generation – not to promote beneficial environmental conditions for the grasses grown beneath – it still provided a more favorable environment during a dry year.’
The research also hints at boosting these results through design tweaks. For example, solar tracking systems that shift panel angles to follow the sun could be adjusted to allow more light through when moisture is plentiful and provide more shade when it’s hot and dry, a potential win for both energy output and plant health.
Sturchio said: ‘With small changes in array design, configuration and management, we may even realise untapped benefits, particularly those related to water use.’
The full research can be read here.
Photo: Colorado State University
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