Study measures impacts of covering fields with solar panels
A team of researchers at Lancaster University and the Centre for Ecology and Hydrology in the U.K. have published the first detailed study of what impact ground solar panels have on their immediate ecosystems and the environment.
The researchers point out that solar ground farms are spreading around the world, which “represents a significant global land use change with implications for the hosting ecosystems that are poorly understood.” Just in 2013, for example, the amount of land used for ground mounted solar arrays rose from 554 to 2,272 square kilometres. It is predicted that their expansion will continue. “This,” says the researchers, “means a significant land use on a global scale and has prompted urgent calls for a detailed understanding of the impacts of solar parks on the fields beneath them.”
The study was done at Westmill Solar Park, a 5-MW plant that has 36 PV array rows covering 12.1 hectares. The rows are 4.4 metres wide with a gap between rows of 11.2 metres. The panels were tilted 30 degrees to the south.
Over a year the researchers measured the solar panels’ impacts on the soil, vegetation, air and greenhouse gas emissions.
Among many findings, they observed that in summer the area under the PV arrays was cooler by up to 5.2 degrees C and drier, compared to areas in the gaps between the panels and a control area.
In the winter, the area under the panels was up to 1.7 degrees C cooler. They also found that the diurnal variation in both temperature and humidity was reduced under the panels during the summer.
Plant growth was four times higher in the gap areas between the panels and in the control area, than on the ground in the solar panels’ shade.
Dr. Alona Armstrong of Lancaster University said the study raises key questions: “Solar parks are appearing in our landscapes but we are uncertain how they will affect the local environment.”
She continued: “This is particularly important as solar parks take up more space per unit of power generated compared with traditional sources…. With policies in dominant economies supporting solar energy, it is important that we understand the environmental impacts to ensure we get more than just low carbon energy from the land they occupy.”
Dr. Armstrong put a positive spin on the situation, point out that in sunny, dry countries the shade under the panels could be used to grow crops that can’t survive in full sun. She also suggested that water could be collected from panel surfaces and used for irrigating crops.
To read the University of Lancaster news item, click here.
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