[Report] A 2,000-Pyeong Farm Under Namseobum Terminal... Vegetables Ready for Dawn Delivery in Abundance

From Abandoned Underground Shopping Mall to High-Tech Farm... NextOn's 'Underground Plant Factory'
Maximizing Growth by Controlling Temperature and Humidity... Annual Crop Yield of 100 Tons
Reducing Electricity Costs by Utilizing Underground Space Characteristics... About 30% Compared to Conventional Smart Farms
All Nutrient Solutions Are Recycled... 43% More Antioxidants Than Regular Lettuce

NextOn's smart farm located underground at Seoul Nambu Terminal Station. It spans 6,942㎡ (2,100 pyeong) and has an area capable of harvesting 100 tons of crops annually.
[Photo by Joonhyung Lee]

[Asia Economy Reporter Junhyung Lee] "I never imagined there would be a farm in a place like this when I came for a job interview."

Nam-Bu Terminal Station, located in Seocho-gu, Seoul. A part of the underground passage connecting the station to the International Electronics Market is currently closed off with panels. At first glance, it seems like construction is underway inside, but that is not the case. When you open the panel door and enter, a 6,942㎡ (2,100 pyeong) farm operated by the smart farm company NextOn appears. This area can harvest about 100 tons of crops annually. A smart farm is a futuristic farm that maximizes crop growth by controlling light, temperature, humidity, and nutrient solutions using advanced technology.

NextOn transformed the abandoned underground shopping area inside Nam-Bu Terminal Station into a high-tech farm. The farm was completed in January and began shipping crops in earnest from March. An employee who joined NextOn at the time of completion said, "When I first came to the company, I got lost for a long time because I couldn't find the way," adding, "I thought there would be workers behind the panels, but I was surprised to see a large smart farm." This shows how the Nam-Bu Terminal Station farm is located in an 'unexpected place' right in the middle of the city.

Abandoned Underground Shopping Area Transformed into High-Tech Farm... Electricity Cost Reduction Effect

The underground space of Nam-Bu Terminal Station, where NextOn's high-tech farm is located, covers an area of 5,629㎡ (about 1,700 pyeong). Originally developed as an underground shopping mall in 1987, it had been abandoned without users for about 10 years. With the help of Seoul Metro, which owns the space, NextOn established a smart farm in a 1,400㎡ (about 420 pyeong) area. They stacked plant cultivators five levels high to increase the actual cultivation area to 6,942㎡, matching the building height.

To enter the smart farm, you must first go through an 'air shower.' This device blows strong air to remove foreign substances from the body and is commonly seen in semiconductor factories. After completing the air shower and entering the farm, you can see the subway stairs. Climbing these stairs leads to a farm surrounded by purple lights. Facilities found throughout the smart farm resemble those inside the station. This is because the Nam-Bu Terminal Station farm utilizes the existing facilities and structure of the underground shopping mall almost entirely, aside from essential equipment.

Unlike the outside station area where daytime temperatures exceeded 30°C, the farm interior was cool. The Nam-Bu Terminal Station farm maintains a temperature of 15?20°C 24 hours a day, optimal for growing lettuce, herbs, and other crops. Air circulators located between cultivators act like gentle breezes. Due to the underground characteristics, the farm is less affected by geothermal heat, resulting in relatively low electricity consumption for temperature control. Choi Seong-kwang, Executive Director of NextOn, explained, "Electricity costs account for a significant portion of smart farm operating expenses. The underground smart farm reduces operating costs for temperature control, enhancing price competitiveness."

To enter NextOn's Smart Farm at Nambu Terminal Station, you must climb these stairs. Facilities commonly seen within the station could be found throughout the Smart Farm.
[Photo by Joonhyung Lee]

LEDs Playing the Role of ‘Sunlight’ Are Key... Ensuring Quality and Freshness

Light-emitting diode (LED) lighting, which aids plant photosynthesis, is one of NextOn's core technologies. The LEDs are adjusted to wavelengths suitable for crop absorption. This is why the LED lights emit purple light instead of typical colors. Unlike general products whose surface temperature rises to 67°C due to heat generation, these LEDs do not exceed 35°C. The combination of LED advantages and the underground space characteristics allowed the Nam-Bu Terminal Station smart farm to reduce electricity costs to about 30% compared to typical smart farms.

NextOn CEO Choi Jaebin's decades of technical expertise accumulated at Seoul Semiconductor, a leading domestic optoelectronics company, served as the foundation. Executive Director Choi said, "Other smart farm companies usually purchase LEDs from Philips or Osram, but we develop our own LED chips, allowing us to optimize lighting wavelengths for each vegetable grown in the smart farm."

They also did not overlook ESG (Environmental, Social, and Governance) principles. The nutrient solution flowing through the cultivator pipelines is a formula directly composed by NextOn. The company uses special equipment to recycle this nutrient solution 100%. Virtually no wastewater generated during crop cultivation is discharged outside the farm.

NextOn utilizes special equipment to recycle 100% of the nutrient solution used for crop cultivation.
[Photo by Lee Junhyung]

They are confident in quality. According to NextOn's research, lettuce grown in the Nam-Bu Terminal Station farm contains 43% more antioxidants such as cynarin compared to organic field-grown lettuce. This result contrasts with the negative perception of crops grown in artificial environments. The company explains that the nutritional value of smart farm crops is guaranteed to the extent that they are developing technology to extract antioxidants from crops for use as bio-new materials.

The crops grown in this farm, such as lettuce, are supplied to e-commerce companies offering dawn delivery and department store food halls. Since vegetables grown in the Nam-Bu Terminal Station farm are also used in franchise cafe salads, they are easily accessible around us. Crops grown in the heart of the city are delivered immediately, ensuring freshness. Executive Director Choi explained, "We will install a robot harvester within this month, which will significantly increase crop supply through automation of the harvesting process."

Smart farm created by NextOn in an abandoned tunnel in Okcheon, Chungbuk. [Photo by NextOn]

Meanwhile, NextOn began gaining recognition by converting an abandoned tunnel in Okcheon, Chungbuk, into a smart farm. The tunnel had been abandoned for nearly 15 years after the old Gyeongbu Expressway was closed in 2002. They stacked plant cultivators 14 levels high in the 6,700㎡ (about 2,020 pyeong) tunnel, securing a cultivation area of 93,488㎡ (about 28,280 pyeong).