Vertical farming dramatically reduces the physical footprint of food production, but given the high cost of energy, it is vitally important for the financial sustainability of vertical farming that it operates as efficiently as possible. For this reason, sensors perform a critical role, which is why Vaisala sensors have been deployed in the UK by the Jones Food Company (JFC) in its existing vertical farms, and in the enormous new facility in Lydney, Gloucester (JFC2) that is likely to become one of the largest vertical farms in the world.
The company’s first commercial vertical farm (JFC1) started production in 2018 with 5,000m2 of growing space and the capacity to produce 150 tonnes per year of fresh produce. JFC2 will be much larger with a growing area of 15,000m2 with a growing capacity of 1,000 tonnes per year.
JFC’s Innovation Centre in Bristol has the capacity to trial ten different crops under different conditions, concurrently. “This is fundamentally important to the success of the business,” explains operational grower Justin Au. “When a customer approaches us looking for a specific crop, we are able to rapidly conduct trials to determine the optimal growing conditions for that crop, and at every stage of its development. The monitoring and control system allows us to change both the intensity and spectra of light from the LEDs, as well as the nutrients in the irrigation water, and the temperature, humidity and carbon dioxide levels in the growing rooms.
“Currently, we are growing herbs such as basil, dill, parsley, coriander, mint and chives; salads such as lettuce, rocket, pak choi, spinach, chard, kale and watercress, as well as other crops such as strawberries. Inevitably, the range of crops that we can grow commercially with vertical farming will continue to expand.”
Water is constantly recycled at all of the JFC facilities with continuous measurements of pH and conductivity helping to ensure the regulation of plant nutrients with dissolved fertilisers. The Vaisala sensors measure temperature, humidity and carbon dioxide, all of which have significant impacts on the growth of plants. “We chose the Vaisala sensors because we need long-term accuracy and reliability, and the control system can only be as good as the sensors, so it makes sense to use the best,” Au says.
JFC’s Innovation Centre control systems were programmed and commissioned by Luke Grundmann, who says that he was particularly impressed with the prompt and proactive support provided by Vaisala engineers to connect and configure their modbus RTU sensors using a generic USB to RS485 converter and freeware software. “The special programming lead had not arrived but even so, the Vaisala engineer skilfully guided me through the process using what I had to hand,” Grundmann explains.
JFC utilises Vaisala sensors as standard, following previous experience with them in a grain dryer control system. Its head of engineering, Christoph Grundmann, says: “At JFC, we are seeking to produce crops as cost-effectively as possible, but it would be a foolish economy to purchase low-cost sensors, because the cost of failure would be high, and the reliability of the Vaisala sensors means that the cost of ownership is low. It was also important for the sensors to have MODBUS communications capability, which saved a significant amount of time and money during installation, and means that any future changes will be quick and simple to implement.”
Temperature and humidity at the JFC facilities are controlled by a separate HVAC system, but Christoph Grundmann says: “The HVAC at JFC1 came with its own sensors, so we have replaced them with Vaisala’s. At JFC2 we will use the Vaisala sensors to check and validate the measurements being made by the HVAC system, and intervene if necessary.”
The first harvest for JFC2 is due in the summer of 2023, and with 15 layers, every acre becomes 15 times more productive. The roof of the new facility is entirely covered with solar panels, and energy will come from renewable sources. Rainwater will be harvested and filtered, and 95% of water will be recycled.
To maximise the efficiency of growing conditions in JFC2, the entire facility will be monitored by a network of Vaisala sensors. They include 46 relative humidity (RH)/temperature sensors, 12 CO2 sensors, 10 temperature/RH/CO2 sensors, two atmospheric pressure sensors and a Vaisala WXT 530 series multiparameter weather station.
Commenting on the monitoring system, Vaisala product manager Antti Viitanen says: “The accuracy and reliability of these sensors will be crucial to the efficiency of the ongoing demand-controlled management of plant growth conditions, because accurate measurements help maximise crop production, while avoiding waste and minimising costs.”
BOX: FARMING IN THE DESERT
Siemens has provided automation and building technology to the recently opened Bustanica vertical farm in Dubai, the world’s largest of its kind. The $40 million facility is owned by Emirates Crop One, a joint venture between Emirates Flight Catering, which serves more than 100 airlines, and Crop One Holdings, an industry leader in technology-driven indoor vertical farming.
Technology from the Siemens Xcelerator portfolio has been integrated throughout the farm to ensure efficient production, reduce waste, and increase the farm’s overall sustainability. Siemens Smart Infrastructure’s building management system Desigo CC controls and monitors air conditioning and ventilation, while Siemens Digital Industries’ Simatic automation and control systems deliver optimal growing conditions by controlling the lights and CO₂ levels required by the plants. Sinamic series variable frequency drives along with automation stations make sure plants receive the right nutrients and water supply. Sentron electrical components distribute power to the grow racks.
Siemens Scalance components create a communication network connecting these automation technologies while protecting the facility with Siemens cyber security solutions. Siemens Xcelerator is an digital business platform that enables customers to accelerate their digital transformation easier, faster, and at scale. At its core is a curated portfolio of connected hardware and software, a powerful ecosystem of partners, and an extensive marketplace.
Bustanica’s system is designed to circulate water to the crops to maximise water usage efficiency. When the water vaporises, it is recovered and recycled into the system, saving 250 million litres of water per year compared to traditional outdoor farming for the same output. The 330,000 sq ft facility requires 95% less water than conventional agriculture, and provides an output of 1 million kg of produce per year that are free of pesticides, herbicides and chemicals.
Bustanica’s produce will initially be provided to airline passengers flying to and from Dubai. The company plans to sell leafy greens and other produce in local supermarkets, and because the greens are grown in a controlled environment, consumers can eat them straight out of the bag.