Plant Factory Mechanism Fully Explained! The Only Guide You Need

Hello everyone! I’m Shohei.

What if fresh vegetables could be harvested every day in the heart of your city?

That dream-like scenario is made possible by a “plant factory.”

Breaking through the constraints of traditional agriculture – weather, location, season…
Plant factories grow vegetables in environments that feel like something out of a sci-fi movie.

It’s truly the “future of agriculture.”

But what kind of mechanism is it? Can you really grow delicious vegetables?
… There are many things you might be wondering about, right?

In this article, we’ll thoroughly explain everything you need to know about plant factories!
From the mechanism to types, advantages and disadvantages, and more.
By the end of this article, you should have a comprehensive understanding.

By the way, some people are worried about whether plant factories have any risks.
I’ve written about that in detail in the following article.

What is a Plant Factory? – The Basics

As the name suggests, a plant factory is a facility that grows plants in factory-like equipment.
But what’s different from a regular factory is that the product isn’t machines, but “vegetables,” right?

And the biggest point is that you can artificially control the growing environment.

What is a Plant Factory? – A “Factory” That Grows Vegetables by Controlling the Environment

More specifically, you can control temperature, humidity, light, CO2 concentration, Nutrient solution (water with dissolved fertilizer), etc., according to the type of crop and growth stage.

Why do we do that?
Because we want to grow crops in a way that is convenient for producers.

In other words, we want to improve taste and quality, or increase production.
Plus, it’s easy to manage because it’s left to machines, and you don’t have to worry about the weather and feel stressed.

So, we’re creating a custom-made environment that is most comfortable for the crops.
The technology for that is a plant factory.

So, what’s the difference between cultivation in fields and greenhouses, and plant factories?
The biggest difference is the “degree of environmental control.”

Open-field cultivation is greatly influenced by the natural environment, such as rain, wind, and sunlight.
Greenhouses can control the environment to some extent, but not as much as plant factories.
Plant factories can produce vegetables stably and systematically, regardless of the weather. This is the biggest characteristic and strength of plant factories.

The History of Plant Factories – Surprisingly Old

Plant factories have been around for longer than you might think.
The prototype of the plant factory was born in the United States in the 1950s. At that time, research began on growing plants in closed environments, aiming for food production in outer space.

Then, in the 1970s, plant factory research started in earnest in Japan.
Against the backdrop of rising concerns about the food crisis at the time, there was a demand for a stable food supply system.

But the initial plant factories were too expensive and never reached practical use.

Plant factories began to develop significantly from around the 2010s.
With the advent of LEDs, power consumption was greatly reduced. That’s when the balance between income and expenditure finally came into balance.

Even recently, the trend of aiming for further labor saving and improved productivity continues.
Plant factories are finally about to enter a period of widespread use after more than half a century of research and development.

Plant Factories Will Become an Essential Technology in the Future

Let me explain.

There are two major social issues behind this.
These are the problems of “stable food supply” and “climate change.”

First, about “stable food supply.”

The world population continues to increase, approaching 10 billion by 2050.
As the population increases, the demand for food will naturally increase as well.

However, the area of agricultural land on Earth is limited.
Moreover, it continues to decrease rapidly due to desertification and urbanization.

Furthermore, in Japan, the aging of farmers and the shortage of successors are serious problems.
If this continues, Japanese farmers will disappear all at once within a few years.

Then who will make the food?
That’s the situation.

And the “climate change problem.”

Recently, haven’t you often heard things like “Vegetables can’t be harvested due to the heat wave”?
Vegetable prices also often go up, right?

In recent years, abnormal weather conditions have become more frequent, causing serious damage to agricultural production.
Record-breaking heat waves, long-term droughts, heavy rains, large typhoons…

This year was terrible…. Will next year be okay?
No, right? There are no other factors that will dramatically improve the global environment.

“Abnormal” weather will continue in the future.

If such situations continue every year, a stable food supply will be difficult.

Plant factories are expected to be a trump card to solve these problems.

Three Forms of Agriculture: Comparing Open-Field Cultivation, Facility Cultivation, and Plant Factories

Plant factories are just one form of agriculture.

I will explain the mechanism of plant factories, but pay attention to the differences from other forms of agriculture.
I think you will be able to understand what kind of characteristics it has.

Three Forms of Agriculture and Combination of Cultivation Methods

Agriculture is broadly divided into three categories: open-field cultivation, facility cultivation, and plant factories.

And there are various cultivation methods,
The following table summarizes which cultivation methods are suitable for each.

	Open-Field Cultivation	Facility Cultivation	Plant Factory
Soil Cultivation
Hydroponics
Solid Medium
Aeroponics

• ◎: Optimal
• 〇: Suitable
• △: Possible with conditions (limited)
• ×: Unsuitable

Facility Classification

• Open-Field Cultivation
  • Cultivation in outdoor fields without roofs or walls. Using natural environments such as sunlight and rainwater, requiring a large area of land.
• Facility Cultivation
  • Using facilities with roofs and walls such as greenhouses. Reducing the influence of outside air and allowing some control over temperature and humidity. Stable production is possible compared to open-field cultivation. Facility construction and maintenance costs are required.
• Plant Factory
  • Able to artificially control the growing environment in a closed space. Optimizing light, temperature, humidity, CO2, Nutrient solution, etc., allowing year-round cultivation and planned production regardless of the weather. Advanced equipment and technology, high operating costs are required.

Cultivation Method

• Soil Cultivation
  • Cultivating plants in soil. Basic crop management is required, such as fertilizer and watering. Widely used in open-field cultivation and facility cultivation.
• Hydroponics
  • Cultivating plants using only Nutrient solution without soil. Clean, with few pests and diseases, and the growth rate of crops is fast. Advanced Nutrient solution management is required, mainly used in plant factories.
• Solid Medium
  • Using solid media such as coconut husk and rock wool. Taking advantage of the characteristics of both Nutrient solution and solid medium. Easier to manage than hydroponics, used in facility cultivation and plant factories.
• Aeroponics
  • Cultivating by spraying Nutrient solution in a mist onto the roots. A type of aeroponics, with high oxygen supply efficiency. Advanced environmental control is required, and can be used in limited environments such as plant factories.

By the way, some people sometimes worry about whether vegetables from plant factories are safe.

In my opinion, the word “factory” has the worst possible image.
If you know the mechanism well, you should realize that there is no risk at all.

What about plant factory vegetables? I have written about this in detail in the following article.
If you are interested, please take a look.

Comparing Differences Between Facility Classifications

The differences between open-field cultivation, facility cultivation, and plant factories are the degree of control over the cultivation environment, productivity, and cost.
Let’s take a look at each difference.

	Open-Field Cultivation	Facility Cultivation	Plant Factory
Environmental Control	Low	Medium	High
Productivity	Low	Medium	High
Quality	Inconsistent	Relatively Stable	Uniform
Cost	Low	Medium	High
Environmental Impact	High	Medium	Low
Stable Supply	Unstable	Relatively Stable	Stable
Climate Change Resistance	Low	Moderate	High
Cultivated Items	Seasonal items	Wide range of items Expanded compared to open-field cultivation	Leafy vegetables, some fruiting vegetables, etc.

Points for Each Item

• Environmental Control:
  • Plant factories highly control temperature, humidity, light, CO2, etc., creating the optimal environment for crop growth. Facility cultivation allows some environmental control, but open-field cultivation depends on the natural environment.
• Productivity:
  • Plant factories have the maximum amount of harvesting per unit area. Facility cultivation has higher productivity than open-field cultivation, but it does not reach plant factories.
• Quality:
  • Plant factories have uniform quality, and it is also possible to control nutritional value and functional components. Open-field cultivation is affected by the natural environment, so quality is likely to be inconsistent.
• Cost:
  • Open-field cultivation has low initial investment, but plant factories have many costs such as facility construction costs, equipment costs, and operating costs. Facility cultivation has intermediate costs between open-field cultivation and plant factories.
• Environmental Impact:
  • Plant factories can significantly reduce water usage and pesticide usage per unit area. However, energy consumption is high. Open-field cultivation requires a large area of land, and the environmental impact from pesticides and fertilizer is also large.
• Stable Supply:
  • Plant factories can be cultivated year-round regardless of the weather, so they can provide a stable supply. Facility cultivation is also relatively stable, but open-field cultivation is greatly affected by weather and seasons.
• Climate Change Resistance:
  • Plant factories are less susceptible to the effects of abnormal weather and are resistant to climate change. Facility cultivation is also more resistant than open-field cultivation, but not as much as plant factories.
• Cultivated Items:
  • Open-field cultivation is mainly seasonal vegetables. Facility cultivation allows the cultivation of a wider range of items. Plant factories mainly cultivate leafy vegetables, but functional vegetables are easy to make.

The Mechanism of Plant Factories

Now, let’s focus on plant factories, which is the main topic of this article.

The image of a plant factory is vegetables planted densely in shelves stacked up and down…

Such equipment uses hydroponics.

Actually, there are many other types of cultivation methods.

Comparing Differences Between Cultivation Methods (Plant Factory)

Plant factories have a closed environment, so hydroponics is very compatible and widely adopted.

In addition, there are cultivation methods that take advantage of the characteristics of plant factories, such as solid medium cultivation and aeroponics.

Let’s take a look at the differences in cultivation methods mainly used in plant factories.

Item	Hydroponics	Solid Medium Cultivation	Aeroponics
Cultivation Method	Cultivation with only Nutrient solution, no soil required	Using solid medium (coconut husk, rock wool, etc.), drip irrigation	Exposing roots to the air and spraying Nutrient solution in a mist
Features	Clean, few pests and diseases, fast growth, easy to automate	Easier to manage than hydroponics, taste closer to soil cultivation, easy to dispose of wastewater	Rich in oxygen supply, promotes root growth, saves space
Advantages	Clean, few pests and diseases, fast growth, easy to automate	Easier to manage than hydroponics, taste closer to soil cultivation, easy to dispose of wastewater	Rich in oxygen supply, promotes root growth, saves space
Disadvantages	Nutrient solution management is important, high equipment costs	Requires disposal of medium, slightly high initial costs	Advanced environmental control is required, high equipment costs, high technical difficulty
Cultivation Examples	Leafy vegetables (lettuce, salad greens), herbs, green onions	Fruiting vegetables (tomatoes, strawberries), flowers	Leafy vegetables, seedling production, research

Comparing Differences Between Facilities (Plant Factory)

In addition to the differences in cultivation methods, they can also be classified by whether they use sunlight or artificial light.

This difference is also quite large, and the electricity bill, equipment costs, and labor costs are completely different.
Sometimes it even determines the success or failure of the business.

Including open-field cultivation, let’s compare four facilities: solar type, combined type, artificial light type.

	Solar Type	Combined Type	Fully Artificial Light Type	Open-Field Cultivation
Ratio of Cultivation Form	44%	14%	42%	–
Main Light Source	Sunlight	Sunlight, LED 81%, Sodium Lamps/Fluorescent Lights 38%	LED 96%, Fluorescent Lights 8%. LEDs are mainly introduced after 2013	Sunlight
Water Source	Well Water 62%, Tap Water 38%	Well Water 60%, Tap Water 33%	Tap Water 78%, Well Water 20%	Rainwater, Well Water, Tap Water, etc.
CO2 Application	Applied in 83%	Applied in 86%	Applied in 89%	Natural CO2 Concentration
Main Cultivated Items	Tomatoes 71%, Strawberries 8%, Fruiting Vegetables Other Than Strawberries 8%, Leafy Vegetables Other Than Lettuce 6%	Tomatoes 27%, Lettuce 27%, Flowers 20%	Lettuce 91%	Diverse
Number of Employees (Year-Round: Regular)	Less Than 110 People 34%. Average 9.8 People Per Facility	Average 9.2 People Per Facility	Average 8.0 People Per Facility	Depends on Management Scale
Number of Employees (Year-Round: Non-Regular/Part-Time)	20-50 People 35%, 50 or More People 24%. Average 44.0 People Per Facility	20-50 People 31%, 50 or More People 31%. Average 46.3 People Per Facility	20-50 People 19%, 50 or More People 21%. Average 28.3 People Per Facility	Depends on Management Scale
Number of Employees (Fixed Term)	Excluding Those Without Employees, Less Than 1-5 People 26%. Average 9.6 People Per Facility	Average 16.4 People Per Facility	–	Depends on Management Scale
Work Ratio in Major Items	Production (Especially Crop Management) Most at 35% or More	Production (Especially Crop Management) Most at 35% or More	Harvesting 27%, Shipping 24%, Transplanting/Final Transplanting 19%, Washing 10% in Order	Depends on Item and Cultivation Scale
Settlement by Yield Per Working Hour	Smaller Deficit Ratio for Larger Yield Per Working Hour	–	Smaller Deficit Ratio for Larger Yield Per Working Hour	–
Cost Ratio by Yield Per Working Hour	Smaller Labor Cost Ratio for Higher Yield	–	Smaller Labor Cost Ratio for Higher Yield	–
Settlement by Yield Per Unit Area	Larger Profit/Break-Even Ratio for Larger Yield Per Unit Area	–	Larger Profit/Break-Even Ratio for Larger Yield Per Unit Area	–
Recent Settlement	Profit/Break-Even 73%	Profit/Break-Even 60%	Profit/Break-Even 45%	–
Annual Sales	Average 430 Million Yen	Average 460 Million Yen	Average 190 Million Yen	Depends on Management Scale
Settlement by Cultivation Area (Major Items)	Larger Profit/Break-Even Ratio for Larger Area	–	Larger Profit/Break-Even Ratio for Larger Area	–
Cost Ratio by Cultivation Form	Labor Costs Largest at 30%	Labor Costs Largest at 30%	Labor Costs Largest at 30%, Electricity Costs 27%	Depends on Item and Cultivation Scale
Cost Ratio by Settlement	Smaller Utility Costs/Depreciation Costs Ratio for Profits	–	Smaller Utility Costs/Depreciation Costs Ratio for Profits	–

※ This plant factory data is based on the results of the “Large-Scale Horticultural Facility/Plant Factory Actual Condition Survey/Case Study” conducted by the Japan Greenhouse Horticulture Association.
※ Open-field cultivation cannot be simply compared with numerical values because conditions vary greatly depending on weather, location, management scale, and crops.

Considering Plant Factories from a Business Perspective

Now, let’s consider plant factories from a business perspective.

Plant factories are attracting a lot of attention as a business opportunity due to their advantages of stable supply, high quality, and reduced environmental impact.

However, of course, there are not only advantages.
If you are considering entry, you should understand the disadvantages as well.

I have written enthusiastically about the advantages and disadvantages of plant factories in the following article.
Please take a look at this as well.

Plant Factories Also Have Quite a Few Challenges

I have been in the plant factory business for many years, and there are still many challenges….

I will summarize the points that you should pay particular attention to.

To be honest, the reason why major companies are withdrawing one after another after entering the plant factory business is due to the following reasons.

• High Initial Costs and Running Costs:
  • Building a plant factory requires a large initial investment in facilities and equipment. In addition, running costs such as electricity bills and air conditioning costs tend to be higher than in traditional agriculture. In particular, in fully artificial light plant factories, a lot of power is used for LED lighting and air conditioning, so cost reduction is a major issue.
• Advancement of Cultivation Technology and Lack of Human Resources:
  • Plant factories require the efficient production of vegetables by making full use of specialized knowledge such as plant physiology and environmental engineering. However, there is a shortage of human resources with this knowledge and experience, and the development of human resources is an urgent task.
• Limited Items and Varieties:
  • Currently, plant factories can only cultivate a limited number of crops. Leafy vegetables such as lettuce are the main crops, and there are many crops that are difficult to cultivate, such as grains such as rice and wheat, fruit trees, and root vegetables.

Various research and development and efforts are being made around the world to solve these problems.
For example, technological innovations are being promoted to save energy and improve efficiency, such as plant factories that use sunlight and the development of environmental control systems that use AI.

However, it cannot be said that it is being used to its full potential. There are still large parts that rely on human hands.

Plant factories are still a developing technology.

Secrets to Success in the Plant Factory Business

So, what should you be aware of to succeed in the plant factory business?

It is necessary to maximize the potential of plant factories while establishing your own strengths.

The points are as follows:

• Clearly Define Targets and Needs: Who do you want to deliver what kind of vegetables to? It is important to clarify the target market and produce vegetables that meet those needs.
  • Example: Neighboring restaurants (rare herbs and baby leaves, high-value-added vegetables), supermarkets (general vegetables with stable quality), health-conscious consumers (functional vegetables and pesticide-free vegetables, etc.)
• Differentiation Strategy: Clarify the difference from competitors! New companies are entering the plant factory business one after another, and competition is intensifying. Therefore, it is important to differentiate yourself from other factories.
  • Differentiation points: Quality, variety, price, service, brand story
• Create Innovation: Always keep evolving! Plant factories are in a field of rapid technological innovation. It is important to always incorporate the latest technologies and information and work to improve production efficiency and reduce costs.
  • Example: Introduction of automated and labor-saving systems, use of renewable energy, research and development of new varieties and cultivation technologies

In other words, in conclusion, you will fail if you just “try to grow and sell vegetables.”

For example, many companies that enter from different industries have a product-out perspective, but they must have a market-in perspective.

Even with vegetables, you won’t be able to sell them unless you have the perspective of “making what sells.”

Also, it is difficult to make a profit with a plant factory unless it has a certain scale.
This is also a point to succeed in business, so please also see the article below for details.

I Can Also Help You Level Up Your Plant Factory

The plant factory business is attracting attention as a growing market.
However, there are many situations where you have a hard time with the operation.

Many plant factories have various problems such as “productivity does not increase” and “vegetables do not sell.”

Please let me help you with the sites that have such problems.

Staff education, training, content provision, etc.
I support plant factories in various ways.

When I was on the front lines of the field, I always thought, “I wish there was someone I could consult with…,” but in reality, there are not many such people.

There is no such service itself.

Therefore, I think I can give you realistic advice that is close to the people on site.

If used well, it can solve management issues and is expected to further grow the business.