rv

Lighting is a very inefficient way to provide heat.
There are ceramic bulbs that fit in a standard light socket that produce infa-red heat, not those red bulbs that you see keeping meat warm at a buffet.
These are non light emitting and have been used in Europe for decades and can be found here through any place that carries reptile supplies.
They are available in several different wattage choices and you can put a rheostat inline to raise or lower the output.
They aren't cheap but they last a long time.
I've had them last as long as 5 years of almost continuous use.