Vertical farming usually uses LED lighting, not direct sunlight.
That’s one method of bringing"sunlight" to plants. Another would be to grow them outside.
And I think the idea is that once the water is present on a given level it gets recirculated and reprocessed there, so it wouldn’t need much additional pumping.
Even if all you do is pump all the water from the floor of each level to the ceiling of the respective level, you’ve done the exact same amount of work as pumping all the water for the top floor back to the roof in the first place. Only you’ve done it with a hundred pumps and a hundred times the points of failure and repair rate as a single pump for the entire building.
You’d be so much farther ahead to just install a reservoir on the roof that gets filled by a single pump and let gravity feed the lower floors. Much the way we already do for flat farming.
And then you’ve got to make up for the inefficiencies lost in planting and harvesting. Vertical farming brings nothing to the table except a smaller footprint in a world where that’s not a real advantage.
A far better use of empty office buildings would be to convert much of the space into full-time living space.
I’m not imagining any problems. The difficulties I’ve outlined are genuine issues that have to be addressed. I think you’d be surprised to learn how much difference there is between a thing existing and it actually operating efficiently.
“Based on an analysis we did for a large private-equity firm, we don’t actually see a scenario where in the next 10 years vertical farming will compete with field-grown at scale in North America,”