Greenhouse agriculture has been growing rapidly worldwide. The controlled environment and high CO2 concentrations inside them can boost a farmer’s yield even in harsh conditions. More than 1.2 million acres (489,000 hectares) of crops were grown inside them in 2016, according to industry estimates.
Peeling off a portion of the sunlight that falls on them to produce energy can also reduce the carbon emissions used in agriculture, helping to head off the bigger greenhouse effect that’s warming the planet.
Scientists have been looking at other methods to harvest solar energy through windows as well. But unlike other technologies, these panels can already be purchased: One of Loik’s co-authors started a company to market them. Your pink, power-producing panels will set you back about $15 a square foot for a new installation, or about $22 a square foot to refit an existing structure, Loik said.
But how’s the food?
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Loik and his colleagues tested the panels by growing a variety of fruits and vegetables — including tomatoes, tangerines, cucumbers, lemons, and peppers. The panels also capture some blue light that plants would use otherwise, but it doesn’t appear to have any effect on their growth, they found.
Not only do the roof panels allow enough light for photosynthesis, but plants grown under them appeared to use less water. It’s not clear why yet, but follow-up studies are focusing on the tiny pores in a plant’s leaves that release water vapor.
“Particularly out here in California and in much of the West, water use efficiency is critical,” Loik said.
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