Generators run on a variety of fuel types, ranging from natural gas to solar power. Keep in mind that fuel costs varying by type:
Natural gas: $2,000–$21,000 per year
Liquid propane: $2,000–$21,000 per year
Diesel: $3,000–$20,000 per year
Gasoline: $500–$3,000 per year
Solar generator: $2,000–$25,000 per unit
Battery backup: $10,000–$25,000 per unit
As a safety measure, you should always turn off the main breaker while operating your generator’s backup breaker. In addition, you should also switch off all appliance breakers so you don't have a power surge when the main breaker turns back on. And finally, turning off the main breaker prevents back-feeding, which endangers utility workers with the risk of electrocution. Back-feeding could also destroy the electrical circuits of your neighbors if they use the same power network.
While the rating will tell you how many watts the refrigerator needs at the peak of its cycle, it requires additional wattage to start. At the bare minimum, you’ll need a 1,500-watt generator to get the fridge up and running after a blackout. A 2,000-watt generator should be sufficient for most home refrigerators.
Whole-house generators can run continuously for extended periods, even for weeks at a time (around 400 to 500 hours), as long as they have a sufficient fuel supply. However, this type of extensive use will increase wear and tear and can shorten the generator's overall lifespan. During long periods of operation, it's important to check and refill the engine oil as needed, potentially as frequently as daily depending on the model. If your generator uses a fuel tank, ensure it is kept full to prevent unexpected shutdowns.
Sizing a generator is a careful process that requires calculating the electrical load of your entire house. You have to take into account every device you want to use and their wattage requirements, plus the wattage needed to start them, and look for a generator that can safely run all that at around 80% capacity.
In more practical terms, a small home can run on a 10,000-watt generator (and if you only want to power a few key appliances, much less than that). A mid-sized home may need something between 15,000 and 22,000 watts. Larger homes require 25,000 watts or more.
The Alamo, NV homeowners’ guide to generator installs
From average costs to expert advice, get all the answers you need to get your job done.
Natural gas generators are whole-home standby generators that are connected to your home’s natural gas line. The average cost for a natural gas generator is $12,000.
Generators should give you peace of mind, but you’ll only get that if your installer knows what they’re doing. Learn how to hire a pro and what red flags to look for.
Thinking about a generator installation? Learn about backup power options, costs to expect, and how to hire the right local pro to keep your home running.