American researchers have said that in the near future greenhouses could become energy neutral by using see-through solar panels to harvest energy – primarily from the wavelengths of light that plants don’t use for photosynthesis.
The team at NC State University used a computer model to estimate how much energy a greenhouse could produce if it had semi-transparent organic solar cells on its roof, and whether that would be enough energy to offset the amount of energy the greenhouse required to operate effectively.
“A lot of the energy use in greenhouses comes from heating and cooling, so our model focused on calculating the energy load needed to maintain the optimal temperature range for tomato growth,” explained Brendan O’Connor, the lead author of the study. “The model also calculated the amount of energy a greenhouse would produce at each location when solar cells were placed on its roof.”
Although the model is complex, it did show that there is a relationship between the amount of photosynthetic light that growers are willing to sacrifice and the amount of energy the panels can generate: if growers are willing to sacrifice larger amounts of photosynthetic growth, they can generate more power. Another benefit is that the panels help to insulate the greenhouse by reflecting infrared light, keeping them cooler in the summer and warmer in winter.
“While the technology does use some of the light plants rely on, we think the impact will be negligible on plant growth – and that the trade-off will make financial sense to growers,” concluded O’Connor.
Photo Caption: The study says that semi-transparent solar panels mean that greenhouses can generate their own energy requirements
Photo source: NC State University