“Profarm T-cube,” a System That Solves Temperature-related Problems in Agricultural Greenhouses, and the Development Process

DENSO Tech Links Tokyo #15 was held on the theme of DENSO’s vision for “manufacturing plants” for agriculture. It introduced “Profarm T-cube,” a next-generation agricultural greenhouse which was developed to make agriculture accessible to anyone, anywhere; “AgriD,” a large-scale agricultural greenhouse; and “FARO,” an automated tomato harvesting robot. Takahiro Bessho of DENSO AgriTech Solutions took the rostrum to explain the significance of DENSO’s efforts to address issues related to food and agriculture, and to explain Profarm T-cube.*
* Profarm T-cube was jointly developed by DENSO Corporation, Daisen Co., Ltd., and Toyotane Co., Ltd.
* Profarm T-cube is the product name of DENSO's Medium-scale Semi-closed Greenhouse.

Dec. 22, 2022

Takahiro Bessho
DENSO AgriTech Solutions

DENSO’s Agriculture Business

I will first give an overview of DENSO’s food value chain business and Profarm T-cube. Our agriculture business is part of the non-automotive business in “DENSO’s Future Direction.” The company has high expectations and gives us much support.

The global financial crisis was one of the factors that drove DENSO to enter the agriculture business about 15 years ago. In 2020 the department name was changed to reflect the new scope of business, becoming the “Food Value Chain Business Development Div.”

What Is the Food Value Chain?

Some of you may not know the term “food value chain,” so let me explain it briefly. A food value chain extends from the farm to your dining table. Our division aims to offer added value in the entire process, not just transport and processing.
Today, I will focus on agricultural production, which is the most upstream part of the food value chain.

Food-related Issues and the Significance of DENSO’s Commitment to the Agriculture Business

I will explain food-related issues and the significance of our efforts. As you know, the farming population has been decreasing even though the global population is increasing greatly. We hope to help ensure the sustainable growth of agriculture and resolve food shortages, which will become important issues.

The environment for agriculture has become severer due to extreme weather and climate change. The amount of food waste has also been increasing. Farm products, which are carefully grown, are thrown away. Our mission is to develop technologies so that agriculture is not affected by climate and location and to add value to the distribution system.

Regarding DENSO’s vision for agricultural operations, we believe that the objective of both agriculture and the automotive components industry is “manufacturing.” The concept is to make agriculture profitable and to make farms more worker-friendly through an industrial approach.

In agriculture, the cultivation area must be increased to harvest more products. However, managing plants, which are living things, requires experience and know-how. Machinery is usually deployed to assist workers, who play the key role.

In industry, the focus is on manufacturing many products in the smallest area and achieving stable mass production through visualization and standardization. Machinery plays the key role and is used appropriately depending on the job.

We aim to contribute to agriculture by using an appropriate industrial approach.

About DENSO AgriTech Solutions

I will briefly introduce DENSO AgriTech Solutions, where I’m working. The company was established through a capital alliance with the Certhon Group, a leading specialist in horticultural facilities in the Netherlands where agricultural technologies have advanced through mechanization and automation. We aim to create and offer added value by combining their agricultural technologies with our manufacturing technologies.

DENSO AgriTech Solutions was set up two years ago. As shown in the lower right of the slide, the number of locations and customers where our horticultural facility solutions are used has been increasing gradually.

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Future Vision of the Food Value Chain

Regarding the future vision, we will be able to play an important role in city planning in line with the development of the food value chain.

Agricultural production may take place in urban areas. Farm products may be immediately processed into food products. An entire city may be connected by a cold chain and other mobility solutions, which are one of our strengths, to manage information properly and guarantee the quality of food products until delivery to consumers. We will contribute to good city planning.

Self-introduction and Profile

I have briefly introduced the work of the Food Value Chain Business Development Div. Now, I will focus on Profarm T-cube, an environmentally controlled medium-scale semi-closed greenhouse.

First, let me introduce myself briefly. I joined DENSO in 2006 and was assigned to the Ceramics Eng. Div. I worked in the design and development of catalyst supports for purifying the exhaust gas from vehicles. So, the early part of my career had nothing to do with agriculture.

After spending 10 years in the division, I volunteered to be transferred to a new business field through the internal job posting system. In fact, I started to work full time in agriculture in 2018 when I began developing Profarm T-cube. In 2020, I was temporarily transferred to DENSO AgriTech Solutions. I work as a sales engineer to sell horticultural facility solutions.

About Growth of Plants and Profarm T-cube

Before going into the details of Profarm T-cube, let’s consider how plants grow. Six main factors are necessary for plants to perform photosynthesis and grow: water and nutrients; light and CO2, which are required for photosynthesis; and temperature and humidity.

The balance is critical. The final energy produced is determined by the most negative of the six factors. We increase the efficiency of photosynthesis by supplying an appropriate balance of all the factors.

A proper environment and appropriate nutrients activate the growth cycle. I might add that the same is true for humans.

Profarm T-cube is our solution. The “environmentally controlled greenhouse” has a system to control the internal environment and is not easily affected by the weather.

DENSO’s “Profarm” is used as the controller.The standard size of the “T-cube” greenhouse is 2,000 m2, which is equivalent to about 10 tennis courts.Let me explain how the system works. Sensors monitor the indoor and outdoor status. Equipment for supplying the six main factors is operated automatically by setting desired environmental conditions in the controller.

Regarding the name “Profarm T-cube,” “Profarm” is a DENSO brand, and “cube” represents box-shaped greenhouses. “T” is for “Triple,” namely, the three companies that developed the Profarm T-cube, which were DENSO, a greenhouse manufacturer, and a nursery company.

Features of Profarm T-cube

Now, I will explain the features of Profarm T-cube. First, let’s take a look at the forced ventilation system, which actively controls ventilation in the greenhouse to improve temperature stability and uniformity.

Ordinary agricultural greenhouses have skylights and side-wall windows, which are opened for natural ventilation.

The lower part of the slide shows the simulation data and measurement data of wind speed distribution (upper row) and temperature distribution (lower row). The temperature increases when there is no wind, which is undesirable.

The forced ventilation system ensures active ventilation as intended. It eliminates stagnant air, increases temperature uniformity, and generates an air flow as needed.  

Concept of the Profarm T-cube Development Process

Next, I will explain the concept and approach of the development process. We apply the concept of standardization and design to the study of specifications of agricultural greenhouses.

Vehicles are developed based on standardization. A vehicle consists of tens of thousands of standardized parts. Standardization leads to stable quality, mass production, and low cost. And because obtained data is reproducible, it can be used for other development work.

Meanwhile, agricultural greenhouses are typically non-standardized. Most greenhouses are arranged to suit the shape of the land. Established know-how cannot be applied to other greenhouses. We thought we could help ensure stability and uniformity through standardization.

In terms of the design approach, human senses vary depending on the person. Accordingly, in experience-based design, the results and decisions vary depending on the person. We decided to design greenhouses by visualizing targets quantitatively and breaking down the mechanism theoretically in an industrial and scientific manner.

Visualization of the Data Measurement Environment for Greenhouses

Now, I will explain visualization. In the industrial design approach that I mentioned earlier, it is necessary to identify phenomena in greenhouses and the underlying factors. Thus, we decided to achieve visualization by developing a system for measuring the environment of greenhouses of commercial sizes.

Agriculture using horticultural facilities is widespread in Toyohashi, Aichi, so we built a greenhouse for development in the city and designated two different areas in the same plot of land: one area where the greenhouse was ventilated using skylights like Profarm T-cube, and the other area where the greenhouse was ventilated using ventilation fans. We analyzed the situation, checked hypotheses, reflected the results in the specifications, and evaluated the performance.

We built a greenhouse and gradually increased the number of measurement sensors, which reached about 300. We made great efforts to visualize the factors.

We measured various phenomena, including the temperature difference between zones in the greenhouse, noise and vibration generated by ventilation fans, and changes in the pressure in the greenhouse caused by forced ventilation. We also derived a formula to calculate the amount of ventilation. We worked on visualization and theory to design the specifications.

Let’s look at some of the results of visualization. The graph on the left shows the results of natural ventilation. The black line is the set temperature, and the blue line is the actual temperature. The green line is the wind speed in the outside air. The graph on the right shows the results of forced ventilation. The actual temperature is closer to the set temperature (black line) than that of natural ventilation on the left.

(In the graph on the left) In the case of natural ventilation, the temperature increased above the set temperature because there was not enough wind and the greenhouse was not ventilated. In the case of forced ventilation, changes in the temperature were minimized by actively using the ventilation system based on the control model, which determined the number of ventilation fans (three in total) that should be operated depending on the amount of ventilation required.

Outlook for Profarm T-cube

Finally, I will explain the future outlook for Profarm T-cube. As shown in the left part of the slide, Profarm T-cube is characterized by a stable, reproducible cultivation environment thanks to its standardized design.

Thus, Profarm T-cube is expected to make agriculture convenient and easy for farmers, enabling anyone, anywhere to engage in farming.

“Group farming” is the future that we envision. For example, to revitalize production areas where there are labor shortages, greenhouses designed for reproducibility and stability will be used by a team of farmers, some of whom may be inexperienced. The know-how of an experienced farmer will be shared to achieve stable results. This will help revitalize production areas.

Profarm T-cube is not a solution for large-scale farming, but we believe it can help revitalize communities by being used by a group of farmers.

That’s all for my presentation. Thank you very much.