I use an oil filled radiator heater since they are safe as they get. Just set a timer for it to pop on when your lights go out. It does pull alot of watts, 3 settings 600watt/900watt or both on for 1500watt. I only use the 600watt setting with thermostat set low. It doesnt really need alot in my grow space to keep it warm, but for a basement you could probably go 600 watt thermostat setting high and it would keep the basement toasty and safe.