vertical farms

vertical farms usually use shelves like in a warehouse 

for the plants to grow in 

that leaves a lot of room in the hallway between the shelves 

for workers and equipment to move in 

but it reduces the amount of area for plants to grow in 

better would be an entire floor full with plants 

that's only 1 or 2 meters high 

with lamps in the roof 

and machines hanging from the roof that could move on rails 

that adds soil, plant seeds, adds fertilizers, water plants 

and harvest plants 

or if it's an aquaponic system, then makes appropriate adjustments 

the machines would be able to move between floors 

by using rails between floors 

which would reduce the amount of machines needed 

and thereby reduce costs 

a warehouse could be used 

with a construction inside that's built with as many floors as possible 

the plants would preferably be short food crops such as: 

potatoes, peanuts and beans 

rice, corn and wheat are too tall 

and would make each floor higher

which could prevent such a system from being economical 

the reason that vertical farms have had financial problems 

is probably because they produce and sell sallads 

and people don't need to eat sallad 

in fact most people don't want to eat sallad 

so produsing and selling sallad is a niche market 

but people need to eat food crops such as: 

wheat, rice, potatoes, peanuts and beans 

businesswise 

people don't need to eat sallad 

but people need to eat potatoes, rice, corn or wheat