- Its not new tech, its greenhouses with indoor lighting
- Its an enclosed large monoculture of plants, which means you are prone to pest and fungus. [see note]
- It has a very large electricity demand (heat and electricity)
- It is labour intensive.
[note]
growing plants in the city is difficult, mainly because the food triangle is so distorted. In central london there are loads of aphids from the lime trees, and lots of powder mildew.
Now considering these setups are aimed at green leafy rapid growth plants, you're going to be spending lots of importing ladybirds. (not much you can do about powder mildew though)
The clean room would explain the cost. if the yield is really 500x traditional farms, that explains why its still more expensive than "organic" produce
Add the tasteless flavorless variety the indoor garden produce.
All those shiny indoor grown roma tomatoes imported from Canada so bland and flavorless in taste.
It's also possible to control a plant's life cycle, and harvest multiple times per year.
On the other hand, it's rare that the economics favor artificial light. Until energy becomes truly cheap, farms are mostly better off with the big fusion reactor in the sky.
Agriculture LEDs are designed to only emit 'growing' wavelengths. But the efficiency losses in converting sunlight to electricity via solar (20% typical) and from electricity to LED light (better, but not great) don't make it any better than growing in a glasshouse.
They try to make solar panels absorb across as broad a spectrum as possible, but they don't absorb everything by default. It's an ongoing research goal to add spectrum without increasing cost.
Would it be practical to make a vertical farm that takes advantage of the sunlight available, and just supplements it in the obscured areas? A vertical greenhouse kind of thing?
- It's much easier to grow plants inside because you don't have to worry about weird weather like frost or insects or fungus etc.
- You can claim organic status and that puts you in a higher price bracket
- You don't need to spend anywhere near as much on transportation so that saves you lots of cash
- You can have much tighter control of supply/demand dynamics (for instance ship smaller batches) because of local proximity
I'm sure there are more but those are the ones that spring to mind.