Solar panels may do more than just harvest energy – they could also help grassland stay greener during drought, according to new research.
A four-year field study has found that semi-arid grasslands partially shaded by single axis tracking photovoltaic (PV) arrays produced up to 20 per cent more plant growth during dry years than unprotected neighbouring fields.
At some microsites, such as the east-facing edges of panels, productivity gains reached 90 per cent.
The findings provide support for the “aridity mitigation potential” (AMP) hypothesis – that PV arrays in water-limited environments can offset reduced sunlight through improved water relations, including higher soil moisture and lower plant water stress.
“Solar infrastructure wasn’t designed to improve grassland health, but under dry conditions, it inadvertently created more favourable microclimates for plant growth,” said co-author Dr Matthew Sturchio from Cornell University.
The study took place at Jack’s Solar Garden, a 1.2 MW solar farm in Colorado, where researchers tracked plant growth under and around panels over wet, average and dry years.
In dry conditions, grass near the east-facing edges of panels – where plants got morning sun and cooler temperatures – grew best, even outpacing nearby open fields.
These edge zones covered just 23 per cent of the site but helped boost overall growth by 19 per cent during dry years. However, the benefit disappeared in average years and turned slightly negative when rainfall was high.
For Australian energy and land managers, the study suggests value in integrating solar and grazing uses – particularly in semi-arid rangelands where rainfall is unreliable and forage shortfalls are common.
With Australia facing more frequent and intense droughts under climate change, such dual-use solar strategies could offer both resilience and emissions reductions.
The authors also note potential to enhance outcomes with adaptive solar array designs – such as anti-tracking configurations that maximise shading when temperatures spike.
Future studies are planned to explore effects on warm-season C4 grasses common in hotter climates like much of inland Australia.
The study was published in Environmental Research Letters.