By Mary Wicks and Peter Ling
Everyone is looking to lower their energy costs, including those in controlled environment agriculture (CEA), which includes greenhouses and indoor farms. What is more important is the energy efficiency to improve profitability of crop production in heating seasons. CEA allows for better control and predictability of the growing environment, including temperature and light, and it can extend the growing season as well as expand food and ornamental crop production to urban areas and harsh environments. But CEA can be energy intensive, although energy needs vary depending on building design and materials, climate, and technology use. Heating, cooling and humidity control and electric lighting typically use the most energy.
Greenhouses have the advantage of natural light but provide little insulation for temperature control. Thus, they may need cooling in summer and heating in winter. They may also need supplemental lighting during seasons when sunlight intensity is diminished. Indoor farming, which often uses existing buildings in urban areas, may have better insulation but will still have some heating, cooling and ventilation needs for temperature and humidity control. And, with no natural light, it requires extensive electrical lighting.
New CEA structures, or retrofitted existing ones can include energy conservation features, renewable energy sources, or other design changes, but these may be capital intensive. Changes to lighting is a less expensive option, but a number of factors need to be considered. While LED lighting can reduce electricity use and does not generate as much heat as high pressure sodium (HPS) lighting, there are concerns about LEDs’ effect on plant growth and crop yield. Changes in cultural practices, such as plant selection and cultivation methods, may also reduce energy use but their limitations need to be considered. Because every operation is different, there is no one-size-fits-all solution.
Learn what growers can do to reduce energy use
On January 26 and 27, 2023, CEA growers will have the opportunity to learn ways to improve profitability of crop production in heating seasons, from lighting options to temperature, humidity, and CO2 control strategies to energy conservation, while maintaining crop quality and yield. The Ohio State University’s Greenhouse Management Workshop, which is held annually, brings together experts in industry and academia to provide practical, science-based information. This year’s workshop will be held at the Wooster Campus, with a virtual option, and will focus on the theme “More with less energy.”
On Thursday morning, OSU researchers will focus on fundamentals, including effects of supplemental lighting on plant growth, insect and disease management, as well as environmental and engineering considerations to improve heating efficiency. In the afternoon, attendees will tour campus greenhouses to learn about current research and then hear from speakers on energy efficiency, conservation technologies, and lighting and temperature strategies.
Friday morning speakers will cover energy impacts of cultural practices, including the pros and cons of cool nights and HPS versus LED lighting. Also, on the program are an overview of growers’ responses to the current energy crisis in Europe, USDA’s Virtual Grower V.4 software for modeling energy usage, and grant and loan opportunities for energy efficiency improvements. The afternoon will feature a tour of a commercial greenhouse.
Pesticide recertification continuing education credits have been requested for Ohio, Indiana, Pennsylvania and Michigan. The flyer (see website) will be updated with credits as they are approved. For program and registration details, visit our website: https://go.osu.edu/greenhouse-2023.
Mary H. Wicks and Dr. Peter Ling, Department of Food, Agricultural and Biological Engineering. Phone: 330.202.3533; 330.263.3857. E-mail: email@example.com and firstname.lastname@example.org. This column is provided by the OSU Department of Food, Agricultural and Biological Engineering, OSU Extension, Ohio Agricultural Research & Development Center, and the College of Food, Agricultural and Environmental Sciences.