A current research study reveals that lettuce can be grown in greenhouses that filter out wavelengths of light utilized to create solar energy, showing the expediency of utilizing transparent photovoltaic panels in greenhouses to create electrical power.
“We were a little surprised — there was no real reduction in plant growth or health,” states Heike Sederoff, co-corresponding author of the research study and a teacher of plant biology at North Carolina State University. “It means the idea of integrating transparent solar cells into greenhouses can be done.”
Because plants do not utilize all of the wavelengths of light for photosynthesis, scientists have actually checked out the concept of producing semi-transparent natural solar batteries that mostly take in wavelengths of light that plants don’t count on, and integrating those solar batteries into greenhouses. Earlier work from NC State concentrated on just how much energy solar-powered greenhouses might produce. Depending on the style of the greenhouse, and where it lies, solar batteries might make numerous greenhouses energy neutral — and even permit them to create more power than they utilize.
But, previously, it wasn’t clear how these semi-transparent photovoltaic panels may impact greenhouse crops.
To attend to the concern, scientists grew crops of red leaf lettuce (Lactuca sativa) in greenhouse chambers for 30 days — from seed to complete maturity. The growing conditions, from temperature level and water to fertilizer and CO2 concentration, were all continuous — other than for light.
A control group of lettuces was exposed to the complete spectrum of white light. The remainder of the lettuces were dived into 3 speculative groups. Each of those groups was exposed to light through various kinds of filters that took in wavelengths of light comparable to what various kinds of semi-transparent solar batteries would take in.
“The total amount of light incident on the filters was the same, but the color composition of that light was different for each of the experimental groups,” states Harald Ade, co-corresponding author of the research study and the Goodnight Innovation Distinguished Professor of Physics at NC State.
“Specifically, we manipulated the ratio of blue light to red light in all three filters to see how it affected plant growth,” Sederoff states.
To figure out the result of eliminating different wavelengths of light, the scientists examined a host of plant qualities. For example, the scientists paid very close attention to noticeable qualities that are very important to growers, grocers, and customers, such as leaf number, leaf size, and just how much the lettuces weighed. But they likewise examined markers of plant health and dietary quality, such as just how much CO2 the plants soaked up and the levels of different anti-oxidants.
“Not only did we find no meaningful difference between the control group and the experimental groups, we also didn’t find any significant difference between the different filters,” states Brendan O’Connor, co-corresponding author of the research study and an associate teacher of mechanical and aerospace engineering at NC State.
“There is also forthcoming work that delves into greater detail about the ways in which harvesting various wavelengths of light affects biological processes for lettuces, tomatoes and other crops,” Sederoff states.
“This is promising for the future of solar-powered greenhouses,” Ade states. “Getting growers to use this technology would be a tough argument if there was a loss of productivity. But now it is a simple economic argument about whether the investment in new greenhouse technology would be offset by energy production and savings.”
“Based on the number of people who have contacted me about solar-powered greenhouses when we’ve published previous work in this space, there is a lot of interest from many growers,” O’Connor states. “I think that interest is only going to grow. We’ve seen enough proof-of-concept prototypes to know this technology is feasible in principle, we just need to see a company take the leap and begin producing to scale.”
Reference: “Balancing Crop Production and Energy Harvesting in Organic Solar Powered Greenhouses” by Eshwar Ravishankar, Melodi Charles, Yuan Xiong, Reece Henry, Jennifer Swift, Jeromy Rech, John Calero, Sam Cho, Ronald E. Booth, Taesoo Kim, Alex H. Balzer, Yunpeng Qin, Carr Hoi Yi Ho, Franky So, Natalie Stingelin, Aram Amassian, Carole Saravitz, Wei You, Harald Ade, Heike Sederoff and Brendan T. O’Connor, 17 March 2021, Cell Reports Physical Science.
DOI: 10.1016/j.xcrp.2021.100381
The paper will appear March 17 in the journal Cell Reports Physical Science. Co-lead authors of the paper are NC State Ph.D. trainees Melodi Charles and Eshwar Ravishankar. The paper was co-authored by Yuan Xiong, a research study assistant at NC State; Reece Henry and Ronald Booth, Ph. D. trainees at NC State; Jennifer Swift, John Calero and Sam Cho, professionals at NC State; Taesoo Kim, a research study researcher at NC State; Yunpeng Qin and Carr Hoi Yi Ho, postdoctoral scientists at NC State; Franky So, Walter and Ida Freeman Distinguished Professor of Materials Science and Engineering at NC State; Aram Amassian, an associate teacher of products science and engineering at NC State; Carole Saravitz, a research study associate teacher of plant biology at NC State; Jeromy Rech and Wei You of the University of North Carolina at Chapel Hill; and Alex H. Balzer and Natalie Stingelin of the Georgia Institute of Technology.
The work was finished with assistance from the National Science Foundation under grants 1639429 and 1905901; the Office of Naval Research, under grants N00014-20-1-2183, N00014-17-1-2242 and N00014-17-1-2204; North Carolina State University; and NextGen Nano Limited.
