“Real-time lighting control is a critical element in our strategy"

In 2015, a group of investors purchased an abandoned 12.5-acre greenhouse facility in North Tonawanda, N.Y., that they named Wheatfield Gardens. Located about 10 miles north of Buffalo, the Venlo glass greenhouse was constructed in the early 1990s by a local power company called Oxbow Power. The greenhouses were initially operated by Village Farms to produce vining vegetable crops.

“In the 1990s, in order for utility companies to build power plants, the companies were required to do something with the excess steam that was generated to produce electricity. Many of these power plants were built adjacent to industrial manufacturing sites.” said Paal Elfstrum, CEO at Wheatfield Gardens. And that’s why the 12.5-acre greenhouse located in North Tonawanda, NY was bought by a group of investors and renamed Wheatfield Gardens. “The power company built the greenhouse facility to be the thermal host for the excess steam the power plant was producing. The steam was piped to the greenhouses to heat the facility.”

But then, regulations changed and the power company lost interest in the greenhouse. “The regulations for the power plants went away in the late 1990s so they no longer needed to have these thermal hosts to operate,” Elfstrum said. “Eventually, the greenhouse was shuttered in 2012, as they could not compete with the imports coming in from Canada and Mexico.”

When Elfstrum and his partners acquired the greenhouse facility in 2015, they initially started with vine crops.

“We had a deal with a local grocery chain to grow eggplants, English cucumbers and beef-steak tomatoes. We were trying to market our crops as the locally-grown option. Unfortunately, it was difficult to differentiate our product even though it was locally grown. For many consumers it’s difficult to tell whether a cucumber has been grown in the U.S., Canada or Mexico.”

Although Elfstrum and his partners wanted to produce commercially profitable crops, more importantly, they wanted to use the greenhouse as a proving ground for their own controlled environment technology.

“We used Wheatfield Gardens as an opportunity to demonstrate our novel patented technology that optimizes the integration of on-site power production with controlled environment agriculture. Behind labor, the second highest operational cost for most greenhouses and all vertical farms is energy. We took an aggressive approach at improving our resource efficiency by using cogeneration and the benefits that come with it, including generating our own heat and electricity. We could also capture the carbon dioxide and deliver it to the plants to increase yields.”

To differentiate its products, Wheatfield Gardens pivoted away from tomatoes and cucumbers to high value crops, including lettuce and herbs which were added in 2016 and industrial hemp for cannabidiol (CBD) production in 2017.

Elfstrum worked with researchers at Cornell University and fellow industry colleagues from the GLASE consortium to look at alternative crops. Butterhead lettuce produced in floating rafts became the company’s benchmark crop. In addition to butterhead lettuce, Wheatfield Gardens is producing multiple varieties of hydroponic lettuce, herbs and auto-flowering hemp cultivars in deep water culture.

“Lettuce travels so far to get to East Coast markets with 90 percent coming from the West Coast,” Elfstrum said. “That travel time doesn’t make sense to me. They are basically trucking water across the U.S. The flavor suffers as well during the long-distance transport.”

In 2018 Wheatfield Gardens installed dimmable LEDs that offered light spectrum control.

“The LEDs allowed us to compete with other lettuce growers and enabled us to be a consistent supplier to our customers year round,” Elfstrum said. “The LEDs were more efficient than high pressure sodium as well as being dimmable and controllable. That’s what we wanted because we are trying to be as efficient as possible without sacrificing quality. For lettuce we look to achieve a daily light integral of 17 moles.”

When the LEDs were installed, the company also installed a light controller.

“The original light controller was very comprehensive, but it was over-engineered for the purpose of controlling the lights and what we wanted it to do.”

The company has recently installed a Candidus light control system to compare its features to the original light controller.

“The Candidus lighting controller enables us to really have tight control over the DLI,” Elfstrum said. “We’re measuring how much energy it takes to achieve the DLI on a seasonal basis. We are able to determine if using supplemental light allows us to reach the lettuce head weight we are trying to achieve.

“The lights will come on if we don’t reach the 17-mole DLI threshold. If it was cloudy all day, the Candidus lighting control system automatically realizes the deficit and turns the lights on at night to reach 17 moles. That’s the beauty of this control system. We can graph when the lights are operating so we can see when the lights were needed.”

Elfstrum said the real advantage of installing the Candidus light controller has been the ability to dim the lights on an active basis to save energy and lower costs.

“We can compete in the winter because we have the LED lights,” he said. “If the sun does come out during the winter, we could receive enough light so the Candidus controller automatically shuts off the lights and we save on energy.

“The Candidus controller, with its sensor at plant level, offers enhanced control. It begins to dim the lights where our other controller will not. The other controller will just shut the lights off. The dimming function on the Candidus controller is a great option because it allows us to save money and we’re not lighting when the sun is providing all the light the crops need. When the sun emerges and provides the light needed, the Candidus controller reacts to conserve electricity.”

Elfstrum also likes the Candidus controller’s ability to track trends and to look at lighting use history.

“The controller really has the functionality that we wanted,” he said. “It is more intuitive than any of the other controllers that we looked at. It was designed by a grower for a grower. Many lighting controllers have been designed by lighting company engineers who don’t have growing experience.”

“Real-time Lighting control is a critical element in our strategy to lower the carbon footprint and costs of Hemp/Cannabis production. The Candidus lighting controls system enables us to collect real-time and historical data that can improve our growing decisions in the future by using AI and machine learning to make more informed adjustments to inputs like CO2 and fertigation.”