Visible solar cells do not absorb light from greenhouse crops

Apr, 2021 - By SMI

Researchers at North Carolina State University discovered that crops can grow in greenhouses with built-in transparent solar cells in a new report. To find out, scientists grew lettuce under different wavelengths of light and discovered that the plants thrived.

Natural solar cells can be made translucent or semi-transparent, and the wavelengths of light they harvest can be modified, making them more versatile over other technologies. In principle, this makes them ideal for incorporating into greenhouse roofs. This organic solar cells could absorb certain wavelengths of light while allowing some to flow through to the plants below. The NC State team looked at how much energy this kind of setup could generate in the past study and discovered that it could be enough to make greenhouses energy neutral.

The researchers have grown groups of red leaf lettuce for 30 days in greenhouses, taking them to full maturity. The various groups of researchers were all subjected to the similar growth conditions, including fertilizer, temperature, and water and CO2 levels. The lettuces were divided into four classes: a control group that received standard white light, and three experimental groups that formed under light that was filtered in various ways. To imitate wavelengths that would be blocked by exposed solar cells, these altered the ratio of red to blue light they received.

The researchers then looked at many indicators of plant health, such as the amount and size of leaves, their weight, how much CO2 they ingested, and how much antioxidants they contained. Surprisingly, the lettuces seemed to flourish regardless of what kind of light they were exposed. Brendan O'Connor, co-corresponding author of the study, states that, "Not only did we see no substantial difference between the control and experimental groups, however, we also didn't see any important difference between the various filters". The team is currently investigating the effects of blocking various wavelengths of light on other crops, such as tomatoes, according to the researchers.