To power a refrigerator, microwave, and several lights, you’d benefit from at least 3,000 watts of power, depending on how much your microwave demands. Typically, refrigerators alone use 300 to 800 watts of power, and microwaves can use up to 1,100 watts. This alone puts you around 2,000 watts. This, plus lights, can reach over 2,000 and closer to 3,000 watts. If you are unsure of the exact wattage that your appliances need to power up properly, it is always smart to have a generator with a larger wattage. If you end up using a generator with a smaller output, you will overload your generator, which can cause your generator to short if it doesn’t have an overload sensor.