If I had a 1kw HPS or MH in my house it would ring alarm bells. It would make my electricity bill sky rocket. If its was used 18 hours during the veg stage then 12 hours for flower thats 18kw a day for a month or 2 then 12kw for another 2 months. I found out that my house uses about 20kw a day which is pretty much nothng. So adding a grow light would go up and might start ringing alarm bells.