Alright, heres my new plan someone tell me if they think it will work. First i have my own orchard and there is a huge drained water tower up on my hill in the middle of the boonies. Im planning on getting 2 more 1000 watt systems to add to my 400 watt. Its cylinder shaped and has one hole on the bottom for me to barely fit my skinny little body into. It is about 12 feet in diameter (from one edge of the floor to the other. I am going to milar it up in there and will have about 50 good sized plants. But first i have to build a frame inside in order to hang my lights from. This water tower is probably about thirty feet high and hasn't been used in years. It has a hole at the very top the size of the one on the bottom for hot air and other stuff to help get vented. These lights may make this tower hot but i am doing it now so it will be much cooler in the fall, I might even be able to grow up there in the winter becuase the lights might keep it hot enough for the plants to live. If not I"ll still have one hell of a grow around December. Oh yeah Im getting a 5000 watt generater to run my lights. The generator will not fit in the tiny whole but there is a fence about 50 yards away with some heavy bushes and green vegitation to help conceal my generator, i will also put a old apple bin which should completely cover it and dig a small trench for an extention cord. What do ya think?
I see several drawbacks. How are you going to supply all the fresh air 50 plants will need? To maximize lumens and cut costs you will have to build an inner chanber. Generators are VERY expensive, loud, and make smoke. It will be VERY noticable. What happens if/when you get bigger?
Honda now make run silent generators petrol engined 4 stroke that supply 110/240v the tanks maybe last 4-7hrs dependant on the power drain dont know how much they would cost maybe £200/$400 more than a regular loud one. Maybe conecting a car petrol tank via fuel lines could get you more running time.
The big hole in the roof and the hole in the side witch you can use for venting, make the entry a propper lockable door & try to put a canopy above the roof hole either that or make sure you have good floor drainage for excess water but a canopy would be better, you dont want rain-water landing on your lights. Sounds like it could be a good plan, if you can afford it just remember if you sell enough your grow room will evetualy cost you $0000=£0000