Advances in transparent solar cells mean that we will soon be able to install them in windows and greenhouses. But in the latter case, could they shield the plants from sunlight? To find out, researchers at North Carolina State University grew lettuce under different wavelengths of light and found that the plants had no problems.
Organic solar cells appear as a reliable system for generating renewable energy, thanks to a series of advantages. They can be more flexible than other technologies, made transparent or semi-transparent, and the wavelengths of light they collect can be tuned.
In theory, this could make them perfect for fitting into greenhouse roofs.
There, these organic solar cells could capture certain wavelengths of light while letting some of it pass to the plants below.
In a previous study, the team from North Carolina State University investigated how much energy such a setup could produce and found that it could be enough to make greenhouses energy neutral.
But, of course, a big piece of the puzzle was missing: No one asked the plants how it affected them. So that was the goal of the new study.
Researchers grew clumps of red leaf lettuce in greenhouses for 30 days, allowing them to reach full maturity. The different groups were exposed to the same culture conditions, such as temperature, water, fertilizer and CO2 concentration. The only difference was the light.
The lettuces were divided into four groups: a control group that received normal white light and three experimental groups that grew under light passed through different filters. These changed the ratio of red light to blue light they received, to mimic the wavelengths that transparent solar cells would block.
Next, the team monitored various markers of plant health, such as the number and size of leaves, weight, the amount of CO2 absorbed, and the levels of antioxidants they contained. And, perhaps surprisingly, lettuce turned out to grow no matter what kind of light it received.
Not only did we find no significant difference between the control group and the experimental groups, but we also found no significant difference between the different filters.
Brendan O’Connor, co-author of the study.
The team says they are currently working to test the effects of blocking different wavelengths of light on other crops, such as tomatoes.
More information: www.cell.com