According to a study from scientists at the University of Georgia, a new, internet-linked lighting system for greenhouses could drastically decrease the electrical bill of a farmer.
The study, recently published in Plants, demonstrated that a predictive lighting control system could enhance lighting for plants by forecasting sunlight and only working the lights when required. The data revealed that farmers could cut their greenhouse electrical costs by nearly 33% by enhancing their lights.
On cloudy or rainy days, plants are given additional lighting to compensate for the inadequate sunlight. While effective, these lights can be costly, inefficient, and use up large amounts of electricity. A 2017 report from the U.S. Department of Energy projected that horticultural lighting consumed $600 million worth of electricity annually.
When LED lights first came to market, they gave us an opportunity to control greenhouse lighting on a level that was not possible before. At the time, a lot of research was happening to optimize the lights themselves, but almost no one was working on smart control of the lighting system.
Marc Van Iersel, Professor, College of Agricultural and Environmental Sciences, University of Georgia
“The electricity used for the lights is anywhere from 10% to 30% of the cost of running a greenhouse,” Van Iersel said. “Our research began with the idea that, if we can reduce this cost, we can very quickly have an impact on the efficiency and sustainability of greenhouses.”
A team of University of Georgia scientists engineered a new lighting system that could decrease a greenhouse’s electrical demand without harming the plants.
Electrical engineering master’s student Shirin Afazli developed a control system that employs sensors to measure current weather situations, and Ph.D. student Sahand Mosharafian and associate professor Javad Mohammadpour Velni formulated light-predicting algorithms in their laboratories.
Together, the system can forecast the amount of sunlight in the future. This allows it to improve the lights inside the greenhouse and supply plants the right amount of light.
Greenhouses are mainly used during the spring and winter, so the researchers verified their system in both growing seasons. While both experiments demonstrated diminished costs while sustaining plant growth, the new system had a bigger effect during the spring. It decreased costs by 33% in the spring but just 4% in the winter.
The system makes the most savings while the sun is bright. As winter months have shorter days, the lights are needed to be on more frequently.
According to the scientists, the real cost savings could be much higher. Their experiments presumed a fixed cost for electricity, but in the reality, farms are conditional on variable pricing. The team has already taught the system to account for this difference and plans to publish future research that demonstrates higher savings rates.
As the population continues to grow, finding ways to harvest more food with limited resources becomes progressively critical.
In 2017, Van Iersel co-founded a startup company, Candidus, based on his study into efficient greenhouse lighting. The company manufactures improved lighting control systems for greenhouses.
Afzali, S., et al. (2021) Development and Implementation of an IoT-Enabled Optimal and Predictive Lighting Control Strategy in Greenhouses. Plants. doi.org/10.3390/plants10122652.