Are protective solar panels the future of French vineyards?
The grapes, planted in 2018 on a commercial vineyard near Perpignan, were grown on a pilot basis alongside a three-hectare outdoor plot of the same three grape varieties.
In addition to producing electricity, the panels were lined up like Venetian blinds (called louver shutters in French) in order to protect crops as much as possible from the scorching sun, hail and frost, as well as to increase soil moisture during the summer.
Alexandre Cartier, spokesperson for Sun’Agri, the company behind the panels, said: “The quality and quantity of the grapes grown under the panels looked superb at harvest and at least as good as the control vines without. panels.
“It is too early to tell if there is a marked difference in the wines produced, but we will see. ”
The panels were spread over 4.3 hectares on the Domaine de Nidolères in Tresserre. This year the test plots were hit by a late spring frost with a wave of polar air.
“There isn’t much you can do to stop the freezing when there is an air mass like that, what we call black frosts, but where the freezing is due to radiated heat when there is no clouds, as happens with hoar frosts, the vines under the panels are protected at 2C compared to other areas next to them, ”said Mr. Cartier.
During heat waves, the difference can be larger, with shaded vines up to 5 ° C cooler than the surrounding area.
The panels also keep the soil moist longer, extending a plant’s growing season by 14 days and reducing overall evaporation by 40%.
When hail threatens, the panels can be closed – they are the same used in rooftop installations and should withstand all but the largest hail. The first harvest was carried out by hand, but mechanical harvesters can pass under panels 5m high.
“We have shown that we are able to make significant differences in terms of temperature, humidity and the amount of light on the vines – all factors which can result in the grower being able to produce the best suited grapes. to the wine he wishes to make, ”said Mr. Cartier.
“It will become more and more important with global warming”
Since the panels are mainly used to control the environment below, their electricity production over a year is between 15 and 20% less than if they were installed for optimal electricity production.
It costs around € 800,000 per hectare to install the Sun’Agri system, which in most cases can be recovered in 10 to 15 years. The panels were also installed in two commercial orchards.
Mr Cartier is confident that more farms will follow, both in France, where there is government support in the form of guaranteed electricity prices higher than for normal panels, and elsewhere.
“With global warming, it will become more and more important,” he said.
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