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A Vertical Farm at 50°C

Imamura here. While running system tests at a new vertical farm, there was a day when I got home and broke out in a cold sweat that wouldn’t stop.

The Ride Home That Day

From morning through evening, I’d been running operational checks on a new environmental control system. Air conditioning, lighting, nutrient solution supply — switching each one on and confirming it responded as intended. Methodical, unglamorous work.

I confirmed that everything was working normally. Satisfied that everything was ready for the next day, I headed home. Opened a beer, bit into some fried chicken, half-watched the TV. A happy start to the evening.

Then a thought drifted across my mind.

“Did I turn off the growing room lights?”

Once that question surfaced, it wouldn’t leave. The AC test, the nutrient solution test, the lighting test — I had a clear memory right up to switching the lights on to test them. What I couldn’t bring back was whether I’d turned them off afterward. The TV that had been background noise stopped registering entirely.

No use trying to push the thought away. I abandoned the fried chicken halfway through and went to start the computer. Fortunately, this system had remote access.

Frozen at the Screen

The moment I opened the remote monitoring display, a sound escaped me involuntarily.

Lights: ON. Grow room temperature: 50.0°C.

For a moment, the numbers didn’t register. 50°C — in the growing room — 50°C. Wait, the sensor maxes out at 50, so the actual temperature might be even higher. A total loss — but nothing’s planted yet. Still, the equipment. Turn it off. Now.

A sealed, isolated space, with high-output LEDs running for hours — of course that much heat would build up. Even so, this was not the scale of “left the lights on” I had imagined. This was nothing like forgetting to switch off the living room light at home.

I grabbed the mouse. Lights: OFF. AC set to minimum. I sat in front of the screen and willed the temperature to drop.

49°C, 48°C, 45°C — each degree felt like it moved at a pace unlike any clock I’d ever watched. The sweat from my palms was transferring to the mouse, making it slip. Whatever buzz I’d had from the beer was long gone.

What saved me was that the facility hadn’t yet started full operation. There wasn’t a single crop growing. Had there been, everything would have been wiped out. The staff coming in the next morning, walking into the smell of vegetables that had been steam-cooked — just imagining it still gives me a cold sweat.

The temperature eventually came back down to normal. The next morning I went in earlier than usual and did a full equipment check as a precaution. Nothing was wrong.

What I Now Do Without Fail Before Leaving

Forgetting to turn off the lights. Misconfiguring the nutrient solution supply settings. Miskeying a temperature setting. These kinds of slip-ups are not rare in a vertical farm. Each one on its own is just an “oh, I messed up” moment — but get unlucky, and an entire crop is wiped out. It’s a genuinely frightening business.

Since that incident, I haven’t skipped my pre-departure checklist once. Lighting, air conditioning, nutrient solution, locks. I go through each item using pointing and calling — pointing at each one and saying it aloud. The list doesn’t literally say “50°C” — but even writing this now, that “50.0” on the screen from that night comes back to me with perfect clarity.

Thankfully, a second 50°C incident has yet to occur.