Earth’s Future http://doi.org/cf5m (2017)

Solar power is undergoing an explosion in capacity with costs falling rapidly. Nevertheless, large-scale deployment of conventional photovoltaic panels in the manner of ‘solar farms’ creates a land use trade-off with agricultural production.

Credit: Derek Meijer/Alamy Stock Photo

Michael Loik from the University of California, Santa Cruz and co-authors describe a promising new technology that can generate electricity while allowing enough light transmission for crop production underneath. The ‘windows’ — called Wavelength-Selective Photovoltaic Systems (WSPVs) — absorb some of the blue and green wavelengths of the light spectrum (green light is typically not utilized by plants) by means of a dye that then transmits a portion to narrw solar panels within the windows. The remaining light, though altered, passes through where it can be utilized by plants for growth.

The technology shows great potential for integrating electricity generation and food production in greenhouses, so Loik and colleagues investigate whether the ‘window’-modulated light affects plant development and physiology. They found minimal effects on the number and fresh weight of fruit for a number of commercial crop species grown under WSPVs. For tomatoes, they even found a small decrease in water use compared with those grown in conventional greenhouses. These panels therefore seem to offer a promising way to decarbonize food production.