I I have to bring my calculator and figure out what 15 1000 watt lights will pull. It will to be close to 150 amps though. It's not going to be cheap. Are you sure the service to your house is going to allow you to pull that much? Are all those lights going to be running at the same time? Sounds like a big commercial grow! In the United States a regular run-of-the-mill house usually has a 200 amp service supplying the entire home. Sounds like you need another two hundred amp service to supply your grow. The hardest part usually in a job by that would be getting a wire capable of carrying all the current in the building to the building. It usually requires a ditch. I don't have a contractor's license myself I just work for electrical contractors. So I don't bid jobs I just do the work. But if you got to change your entire service into a 400 amp service to make all this happen that's going to run you in and of itself close to a thousand probably, then probably damn near another thousand 4 getting the wire to the building and wiring up the building.
Like I said I don't bid jobs so I'm just throwing those numbers out loosely. But you're definitely going to be paying a good chunk of change. Especially if you require that service change, that's going to pretty much double it.
Is the same scenario in a basement you're just going to have to get a wire capable of carrying 200 amps from your main panel to the basement. Maybe a misunderstanding and you're not trying to run 15 separate 1,000 watt light fixtures. Doing it in a basement instead of an exterior building or bring the cost down a little bit. Like I mentioned a couple times already the ball buster is going to be a service change. And like the gentleman above-mentioned some houses are old have knob and tube wiring, and those are nightmares and very expensive nightmares for the homeowner. It also depends if you're going to get all this work inspected. Being the it'll be in a basement everything's going to have to be GFCI protected. Just make sure you get somebody that knows what they're doing