A:Answer It will depend on what type of 30W bulb you use in the LG 1.8 cu. ft. Over the Range Microwave Oven, Model # LMV1813ST. The maximum watts requirement has to do with heat since all bulbs give off heat. The higher the wattage, the more heat is created. There are CFL bulbs and incandescent bulbs available. CFL bulbs are marked with two numbers, the equivalent wattage which compares the light output to a incandescent lamp, and the actual wattage consumed by the bulb. The actual wattage is what you need to stick with. A 75 watt equivalence CFL gives off the lumens (brightness) of a 75 watt incandescent bulb. But it only consumes 13 watts, and thus gives off the heat of a 13 watt bulb. CFL bulbs operate at much lower voltages and temperatures so you should have no problems using a CFL that gives an equivalent amount of illumination to a higher watt incandescent bulb as long as the fixture can accommodate the physical size of the CFL. You should have the Sales Associates at Home Depot qualify you on this, but if unsure, complying with the recommendation prevents fires because a higher wattage may overheat the fixture causing damage or a fire...^IFV