Ok, you gotta look at the numbers to see this. It costs me $40-50 a month to run a 1000W for 12 hours/day and 400W for18 hours/day. Wattage is wattage. The space heater is a great way, they are usually around 1000-1200W.

The watts add up per hour, so if you run 1000 for 12 hours, that is 12 KW. A 400 for 18 hours is 7.2 KW. Total of 19.2 KW. If you pay $0.10 (a high number I think) per KW, that is like 1.92 per day or so.....That sounds high. My electricity is around $0.075 per KW. Also you have to consider fans, heating pads. heaters if you are using them.

So if you want a good story, fabricate one that uses KW hours correctly.