You can determine what size generator you need for a transfer switch by matching the switch to the largest outlet on your generator. Larger generators can power up to 10 circuits, while most 5,000-watt generators can provide power to six circuits. So, if your generator’s largest outlet is 30 amps, you’ll need a 30-amp transfer switch.

While diesel is relatively stable, it won’t last nearly as long as propane and you may have to replace it if it sits unused for too long. Diesel can sometimes struggle to work efficiently or start engines during especially cold weather, so it’s not the best choice for every climate. Compared to fuels like propane and natural gas, diesel generators tend to be noisier and create more exhaust, which isn’t always ideal for home use.

These advanced generators use a key fob or a smartphone app to remotely start, which is ideal for getting power back on immediately without venturing outside. This feature is more common on whole home generators, but you may be able to find it on large portable generators, too.

If you’re wondering whether gas generators produce carbon monoxide, know that natural gas generators do not produce carbon monoxide if they are functioning properly, as natural gas burns cleanly. However, if the generator malfunctions and the gas does not burn completely, there is potential for carbon dioxide to be produced. To prevent malfunctions, it's crucial to perform regular maintenance, including running the generator weekly and scheduling professional inspections every 6 to 12 months. Also, be sure to test your carbon monoxide detectors regularly to ensure they function in the rare case of the generator producing carbon monoxide.