The first thing is to differentiate between home gardening and commercial designed systems.
For the home you can build your own, or buy something like a Tower Garden.
Commercial systems are in a shipping container or in a warehouse.
Light is provided by LEDs to simulate sunshine.
Every company selects its own colour (spectrum).
A shipping container can be set up in an urban environment, being only 40’x 8′. But, it’s production is small and it has a high capital cost.
Containers works for schools, in food deserts or high-end restaurants. Freight Farms is the biggest name.
Warehouse production is between 500,000 and 2,000,000 lbs of veggies a year which is enough for one salad SKU in a large chain in NYC. Warehouses range from 15,000 – 200,000 sq. ft.
Growing is either bunk-bed style or tower style.
Bunk beds are what most people think of. Aerofarms and Bowery are the biggest names.
Tower growing is more efficient in space and harvesting and has less technical problems.
Local Salads and Plenty are the biggest names in Tower growing.