Sheep living among rows of solar panels spend more time grazing, benefit from more nutritious food, rest more and appear to experience less heat stress, compared with nearby sheep in empty fields.
suggested that agrivoltaic farms – which combine grazing animals with solar panels – offer more efficient renewable energy at lower overhead costs, as well as reducing wildfire risks. The latest findings show that the practice is also good for animal welfare, providing further evidence for a win-win situation, says who carried out the work while at Wageningen University in the Netherlands.
She and her colleagues placed data loggers on the necks of 80 ewes, most of which were pregnant, living on 7.5 hectares of pasture on the central coast of California. The pasture, owned by , hosts 4.5 megawatts of solar photovoltaic power produced from panels that automatically face the sun.
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The researchers placed half the ewes in areas with a 60 per cent coverage of solar panels, and the other half in areas without any panels, in late autumn and winter, when temperatures averaged 17.5°C (63.5°F). They also sampled grasses from each grazing area to assess the amount and quality of vegetation the sheep consumed.
They found that the sheep on pasture with solar panels spent more than 70 per cent of their time under the panels and grazed 8 per cent more than those on land without solar panels. The sheep also spent 71 per cent more time lying down compared with those in open pasture, and 16 per cent less time just standing around idle – a behaviour that hints at poor welfare.
“They really liked being under the solar panels,” says Kampherbeek, adding that she herself preferred being in the shade under the panels. Heat stress is a common problem for sheep, which not only causes discomfort, but can lead to deadly heat stroke.
As for pasture quality, the nitrogen content was higher and carbon content lower in the solar panel fields, suggesting that the vegetation in this pasture – which was greener – was more nutritious and more easily digestible. That might be due to the reduced exposure to intense solar rays and to dew dripping off the panels, providing much-needed moisture, she says.
The results are likely to be even more pronounced in warmer seasons, she adds. Additional research is under way to analyse the data taken from temperature recordings during her study.
Sheep make good candidates for agrivoltaics because they are efficient foragers, keeping weeds off solar panels, and are small enough to pass under the panels, says Kampherbeek. And, unlike goats, they don’t chew the electrical wires.
The findings strongly suggest that solar power centres should be designed with a partner animal species in mind, she says.
Applied Animal Behaviour Science
