In a small footprint you need drastically-lower energy requirements. Also, with the advent of LED lighting, you use even less in atmospheric regulation, which becomes the major power-saver outside of the lighting itself.

Also, the trick to vertical tomatoes is not what most people expect. They should look more into the upside-down pot idea and think about how best to take advantage of a top-down hanging system, like near-360 degree lighting between rows of hanging tomato plants to maximize exposure along the entire length of the curtain. These can be mounted horizontally under the nft channels the hanging plants grow from, allowing them to receive all the light they want while leaving walkway space (and overhead human-vision lighting space.)

It takes a LOT of research to make things work and everyone just promises a turn-key system. THAT can't work. My systems work because of research and lots of first-principles thinking.