Colorado researchers double saffron harvest on solar-shaded rooftop, earning $60,000
A Colorado State University team showed that saffron grown under semi-transparent solar panels yields twice as many flowers and twice the dried spice compared with unshaded plots, while also generating electricity and projected net revenue of about $60,000.
Researchers at Colorado State University investigated how a green roof equipped with semi-transparent solar panels could support saffron cultivation. Conducted on a 46-kilowatt array covering 4,356 square feet at the CSU Spur campus in Denver, the experiment used panels transmitting 30-40% of light and positioned 6-8 feet above the planting medium. Compared with fully exposed rooftop plots, the shaded beds produced twice the number of saffron flowers and twice the amount of dried spice.
A five-year financial model projected net earnings of about $61,000 from electricity, dried saffron (priced at $35 per gram) and corm sales, although initial costs would exceed revenue in year one. The findings echo earlier Moroccan research that identified 30% shade as optimal for saffron yield. While the approach promises additional seasonal income for cities, it also requires labor-intensive planting and hand-harvesting, and careful planning for maintenance of both the photovoltaic and agricultural systems.
Why it matters
It shows how solar installations can simultaneously generate power and high-value crops, offering a new revenue stream for urban rooftops.
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