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The U.S. power grid is suffering more outages than ever—about 45% of utility customers experienced one in the first half of 2025—and the resultant blackouts are lasting longer. As our aging electrical grid struggles to keep up with increasing air conditioner use due to a hotter planet, not to mention artificial intelligence’s insatiable thirst for power, the problem will likely get worse: The U.S. Department of Energy estimates the risk of power outages will increase a mere 100 times over the next few years.
If you’re looking to stave off the worst of the fallout from our shaky power grid, you might be looking to purchase a backup generator (not to be confused with a rechargeable power station) to ensure you can ride out an outage in relative comfort. But you really shouldn’t just roll up to the hardware store and buy whatever generator is on sale. Choosing the right generator for your home and your circumstances is essential. Here are the factors to consider.
How much power does your backup generator need to supply?
The first step in determining the right generator for your home is to determine how much power you’re going to need. This requires three data points: How long you’ll need generator power, how many things you’ll want to run off the generator during a power outage, and the wattage those appliances and systems will need.
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Duration. You can’t predict the future, but you can glean some information from your neighbors (or your own memory) about past power outages. Did they last for several uncomfortable days, or were they relatively brief? If the latter, you might not need a lot of backup power, unless you want to be prepared for any eventuality.
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Number of appliances. Think about what you’ll need to run off a generator. Will it be just a few lights and some phone chargers, or will you want to keep the heat on, run the refrigerator, and run a sump pump during a storm? Everything you add to the list will increase the capacity of the generator you’ll need.
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Wattage. Once you know all the things you’ll need to run, you’ll need to add up the wattage a generator will have to produce. Most appliances will have that information on a label somewhere; if not, the information’s usually in a user manual or online. If the label only provides amps, you can usually multiply that number by 120 (the standard voltage in most homes) to get a rough idea.
Add all those watts up, and you have a baseline of your power needs during a blackout. Some appliances, like a sump pump, will pull more power when they start up (called starting watts) before settling into a lower power draw (running watts), so it’s a good idea to multiply your baseline by 1.5 to ensure you have enough capacity for surges when the pump or fridge compressor cycles on and off.
For example, let’s say I want to run my fridge (600 watts), a sump pump (1,000 watts), my computer, and a few lights (400 watts combined). That’s a baseline of 2,000 watts, so I probably want a generator capable of producing at least 3,000 watts of power.
Should you choose a portable, inverter, or standby backup generator?
Next, you need to consider what kind of generator you’re looking for: A standby generator, a portable generator, or an inverter generator.
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Standby generators are the most expensive, but also the most comprehensive solution. These are typically fueled by natural gas directly from your home’s supply line (though you can buy models that use propane), and are designed to turn on whenever there’s a power loss. They’re big generators that are capable of running the whole house, often generating as much as 20,000 watts. They’re ideal if you anticipate frequent and lengthy power outages, or if you just want the peace of mind of knowing that you’ll enjoy uninterrupted power even if a storm knocks out your whole neighborhood. Typical cost: $8,000 to $16,000, usually requiring professional installation, and you’ll need outdoor space where it can sit.
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Portable generators are the most common and typically the most affordable. They have wheels and are designed to be moved around as needed, and range from as little as 1,000 watts of output to behemoths that can generate 20,000 watts (though the word “portable” starts to get a bit squishy with a generator that large—this model, for example, weighs 557 pounds). These are ideal for most people who just want a power option, and for folks who might use a generator at other times, like camping trips or when doing DIY projects around the house. Typical cost: Anywhere from $300 to about $4,000, depending on the specifications.
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Inverter generators are similar to portable generators, but run much more efficiently and quietly because they don’t run flat-out like most portable generators, they throttle up and down depending on the draw. They use less fuel and run longer, and are also usually mounted on wheels for portability—and their quieter operation also generates less interference for electronics like computers and routers. Many can produce enough power to run an entire house (typically around 5,000 watts), but they’re also typically much more expensive for the power they deliver. If you have the extra cash, an inverter is probably your best bet. Typical cost: About $350 to $4,500, depending on specifications.
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Power stations. Although sometimes referred to as “solar generators” because they can charge using solar power, these aren’t really generators—they’re large batteries that store power for later use. You can buy portable power stations that generate sufficient wattage for a whole house, and you can have larger systems installed that can take you off the grid entirely. They tend to be more expensive to purchase but cheaper to re-charge. But their main limitation is time: Once a power station is drained, it can be difficult (and slow) to recharge them using solar power alone.
What fuel will your backup generator use?
Another consideration for portable and inverter generators is the fuel type. As noted, large standby generators will usually run off of natural gas or propane. Smaller portable and inverter generators offer a few more options:
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Gasoline is the most common fuel type for portable and inverter generators. Gas is usually easy to buy, but gasoline goes bad, so you can’t just leave it in the tank or have a bunch stored in the garage indefinitely. You’ll have to drain the fuel tank when you’re not using the generator regularly, and make sure you stock up on fuel (or know how to siphon it from your car) when you think the power might go out.
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Propane. You can buy generators that hook up to a standard propane tank. Propane can be stored much longer than gasoline, and you don’t have to worry about draining a tank. But propane can be more challenging to acquire, depending on where you live. If your house already uses propane and you have a large tank on the property that gets refilled regularly, this might be the perfect choice.
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Diesel. Diesel generators usually require less maintenance because of their simpler design and the self-lubricating properties of the fuel. As a result, these generators can last longer than other models and require less attention. On the other hand, diesel fuel generates a lot of smoke and bad odors, and might not be convenient if you don’t live near a source.
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Dual and tri-fuel. If you want as many options as possible, you can buy dual fuel generators that can run on either gas or propane, or tri-fuel generators that can also use natural gas. These generators tend to be more expensive, of course.
Other backup generator features to consider
Finally, a few things you might want to pay extra for:
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Electric start. Most generators use the old-school pull-cord to start the engine. If you have trouble getting those going or have a physical limitation that makes that difficult, you can find models with a car-style push-button starter that can make life a lot easier. Keep in mind this will require a battery to be hooked up to your generator.
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Automatic shutdown. Generators are engines, and as such they generate pollution—you should never run a generator inside the house, or even too close to the house. Having a generator with a carbon monoxide detector that shuts down if it detects too much exhaust is an extra safety feature you might want to consider. Generators typically use oil for lubrication, too, so having a low-oil detection feature that shuts the generator down before it can damage itself is another feature you might want.
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Receptacles (aka spots to plug things in). All the wattage in the world won’t do you much good if you don’t have enough receptacles to plug into, so make sure you do a count before you buy.