On a warm late winter morning, Antonio Lancellotta, a 35-year-old farmer, shows me around one of his family's unorthodox 1.8-acre (7,280 square metre) greenhouse in Scalea, southern Italy. Rows of lush citron trees (Citrus medica), heavy with white flowers fill the space. Yet, above the trees, at about 12.5ft (3.8m) above the ground, alternating lines of transparent plastic sheets and photovoltaic panels roofed the field.

The Lancellotta family was one of the first in Italy to experiment with "agrivoltaics", where crops are grown underneath solar panels. "Look at the quality of this citron," Lancellotta says, holding a large heart-shaped yellow fruit. "Perfect."