How to build a successful vertical farm

By Ellis Janssen, Global Director City Farming at Signify

The interest in growing plants indoors in vertical farms keeps increasing.

Business expert Ellis Janssen shares 3 key lessons learned from building a successful vertical farm enterprise around climate, lighting and spacing.

The most crucial part when setting up an indoor farm is to have a grower that understands how to cultivate plants indoors. New (sensor) technologies and the Internet of Things (IoT) offer great opportunities for indoor farming, but if you don’t have a grower, you will not get out the most of your operation. You can have great packaging and attractive marketing tools, but the product itself will determine your success. That being said, these are some of the most important factors that can determine the success or failure of your vertical farm investment:

• Crop selection
• Lighting selection and design
• Airflow design and climate control
• Spacing strategies for plants
• Crop logistics and automation
• Irrigation and nutrition
• Data, sensors, control and software
• Substrate choice
• Target audience and sales channels

When we look at how to get the highest return on investment for a vertical farm, we focus on creating a facility that allows you to produce the highest yield of crops (measured in grams) using the most ideal amount of light (measured in moles or mol). That’s because your LED grow lights are amongst the highest expenses in city farming infrastructure and operation. Keeping that in mind, here are a few of our most valuable tips for increasing your grams per mol. The information is based on research from the Philips GrowWise Center, as well as commercial projects in a variety of locations ranging from the US to Japan and Europe.

Step 1: Get the climate right

One aspect that many new vertical farm growers overlook when creating an indoor farming environment is maintaining the best climate conditions. If we assume 50% of the electrical input power is converted into light, the remaining 50% is converted directly into heat. Proper airflow can remove direct heat, but the light that is absorbed by crops will indirectly be converted into heat too. Typically, crops evaporate water to  eliminate indirect heat, however this process results in  higher humidity. To keep increasing humidity and temperature under control, you must implement a good ventilation and air handling system in your vertical farm. Without this, yields will decrease, resulting in additional costs and hassle after installation to fix inefficiencies.

Step 2: Get the lighting right

Once you have established  good climate conditions, how can you get the highest yields from it? We have done hundreds of research projects on growing plants indoors, focusing on yield and the most optimal light intensity for a certain crop or variety. Yield, however, is not always the most crucial and single most important part. Let’s take red oak lettuce as an example. When this lettuce is grown outside in a field it turns red because of stresses from sunlight and temperature variations, and it typically yields less compared to its green counterpart. When the same variety is grown indoors, it remains mostly green in the absence of UV light, while showing comparable or sometimes even better growth than the green version. At the Philips GrowWise Center, we have four full-time plant specialists who develop so-called light and growth recipes for specific crops. Based on their research, we developed a coloration light recipe for red oak lettuce that turns a mostly green head of red oak lettuce into a dark red lettuce in just three days. Growers can cultivate a large head of lettuce in their regular growth cycle, apply this light recipe as a pre-harvest treatment, and get a great quality crop with much higher yields and the proper appearance. Together with breeding companies we screen and develop varieties that could help them differentiate their products even more based on taste, quality or colour.

Step 3: Get the spacing right

The spacing strategy you use when growing plants indoors is another way to improve your grams/mol. You want to space plants so that each one gets an optimal amount of light, and so that you are lighting the plants rather than shelves. Knowing the ideal spacing strategy can avoid you having to invest in spacing robots, because you can check the extra yield spacing plants delivers, compared to the investment needed for the automation of this strategy. For vertical farm projects, we can contribute to your business calculations with advice on the best spacing and light recipe for each crop. Based on that information, you can decide if manual spacing, or spacing robots are the most cost-efficient choice for your facility. Our cooperation with the leading breeders in the industry will also enable you to pick the right variety for your crop specific requirements.

Ellis Janssen is the Global Director City Farming at Signify, Horticulture LED Solutions. With a background in international business, Ellis has several years of experience in lighting & vertical farming. Ellis leads the multi-disciplinary team of plant specialists, sales application engineers and business developers to build vertical farms globally, tailored to the specific, local business needs of the customers /entrepreneurs. Keys to her work are her passion for food, people and sustainability.

Signify is a Partner of the Asia-Pacific Agri-Food Innovation Summit and Rami Hajjar, CEO South East Asia, will speak on the panel ‘Improving Resource Efficiency and Scaling Production for Indoor and Rooftop Farms’ on November 18, 2021. View the full agenda.