Could tinted solar panels boost crop yields and farms’ incomes?

Researchers at the University of Cambridge say they have demonstrated the use of such solar panels to generate electricity and produce ‘nutritionally-superior’ crops simultaneously

Could the use of tinted and semi-transparent solar panels result in leafier and more nutritious plants and boost the income of farms through electricity generation?

Researchers at the University of Cambridge say they have demonstrated the use of such solar panels to generate electricity and produce “nutritionally-superior” crops simultaneously, which they believe can result in higher incomes for farmers and maximise the use of agricultural land.

The use of crops and electricity have already been produced simultaneously using semi-transparent solar panels – a technique called ‘agrivoltaics’.

But in a new adaptation, the researchers at Cambridge used orange-tinted panels to make the best use of the wavelengths, or colours, of light that could pass through them.

They used basil and spinach plants as test crops and grew them under tinted solar panels that absorbed light from the blue and green parts of the spectrum, while filtering the orange and red lights to the crops below, which is important for photosynthesis.

While the crop receives less than half the total amount of light it would get if grown in a standard agricultural system, the colours passing through the panels are said to be the ones most suitable for its growth.

Dr Paolo Bombelli, a researcher at the University of Cambridge’s Department of Biochemistry, who led the study said: “For high value crops like basil, the value of the electricity generated just compensates for the loss in biomass production caused by the tinted solar panels. But when the value of the crop was lower, like spinach, there was a significant financial advantage to this novel agrivoltaic technique.”

The researchers found the combined value of the spinach and electricity produced using the tinted agrivoltaic system was 35% higher than growing spinach alone under normal conditions, however, by contrast the financial gain for basil grown in this way was only 2.5%.

The calculations used current market prices – basil sells for around five times more than spinach.

The value of the electricity produced was calculated by assuming it would be sold to the Italian national grid, where the study was conducted.

Professor Christopher Howe at the University of Cambridge’s Department of Biochemistry, who was also involved in the research added: “Our calculations are a fairly conservative estimate of the overall financial value of this system. In reality if a farmer were buying electricity from the national grid to run their premises then the benefit would be much greater.”

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