Greenhouses and solar panels both need to be placed in areas with a lot of sunlight – so why not combine the two?
Semi-transparent solar cells could potentially be built into the glass roof panels of greenhouses, capturing light at wavelengths that plants don’t use anyway. Now, researchers at North Carolina State University have modeled how this might work and found that in some climates the cells could produce enough solar energy to make the greenhouse completely self-sufficient.
Organic solar cells (OSCs) have a few advantages over other designs. They still collect energy from sunlight, but can be made more flexible, transparent (or at least semi-transparent) and can be tuned to only absorb certain wavelengths of light. That potentially makes them perfect for greenhouse roofing – they can let most light through for the plants while harvesting enough to offset a decent chunk of the facility’s energy needs.
For this study, the theoretical greenhouses were modeled on the energy needed to grow tomatoes in three locations with different climates – Arizona, North Carolina, and Wisconsin. In the famously sunny Arizona, for example, a greenhouse with OSCs installed could become energy neutral while blocking just 10 percent of the light the plants need, which, according to the researchers, wouldn’t harm the plants.
In North Carolina, sunlight is a little more sparse, so a greenhouse would need to block 20 percent of the photosynthetic light to become energy neutral. Chilly Wisconsin winters would be too much to ever achieve neutrality though, but these greenhouses could still generate almost half of their energy needs.
The study, which was published in the journal Joule, could pave the way for self-sufficient greenhouses in the near future.
