We researched dozens of generators, considering size, wattage, fuel source, battery life, and maintenance. Our top overall pick, the Generac Guardian 24kW Standby Generator (Model 7209), is Wi-Fi enabled for easy monitoring and is one of the largest air-cooled generators on the market. Here are the top home generators. This popular generator model maximizes power output but minimizes space requirements. The housing of the unit is 4 feet long and 2 feet wide, which is larger than the most compact generators available but on par with typical whole-home generators. Generac also equipped this unit with a Quiet-Test weekly self-test mode that operates at just 57 decibels. During regular operation, the generator is rated for 67 decibels, which is average operating noise but impressive for a generator of this power capacity. Keep in mind that this model doesn’t include a transfer switch, so you’ll need to purchase that separately. Price at time of publish: $6,397 As expected for a bare-bones generator, this model doesn’t have the ability for Wi-Fi monitoring. It also lacks an engine hour meter, but an aftermarket meter can be installed to help you keep up with routine oil changes and maintenance. To make maintenance and repairs easier, three sides of the aluminum enclosure are removable. Price at time of publish: $2,991 Regardless of what climate you live in or what season it is, this standby generator is equipped with a 24-volt starting system rated for use in temperatures ranging from -22 to 104. A battery tender ensures that the onboard batteries will always be ready to provide starting power. Take note that you’ll need to buy the batteries separately. Price at time of publish: $3,799 Considering its reliable several-hours runtime, this unit seems a reliable propane-powered solution to the increasingly frequent controlled power outages many communities have adopted to save energy. To ensure continuous electric power during disasters such as hurricanes, however, it may be more sensible to use gasoline instead of propane. Price at time of purchase: $1,499 The WEN GN6000 stands out among portable generators for being transfer switch-ready, thanks to a NEMA L5-30R outlet. It has plenty of other outlets, too—including two 120V household outlets, a single 120V 30A RV receptacle, a 12V DC outlet, along with the previously mentioned 120/240V four-prong outlet. With a half-load, you can expect this portable generator to run for up to 7.5 hours before it’s time to refill the 3.4-gallon gas tank. Price at time of publish: $461 The Goal Zero Yeti 1500X isn’t equipped to replace a whole-home generator, but it can serve as a short-term power supply. There are no fuel gauges to monitor, maintenance to perform, or exhaust fumes to worry about. In the event of a power failure, plug your most important devices and appliances into the outlets of the Yeti 1500X, which includes a pair of 120V AC outlets or USB ports. Price at time of publish: $2,000 Weekly self-testing by the Generac Guardian Backup Generator ensures that it’s ready to supply power to the most important systems of your home. This model conserves fuel and operates quietly, thanks to a short five-minute test cycle that operates at just 57 decibels. Price at time of publish: $3,279 Start by understanding how much power each home component needs. While an appliance’s actual wattage is shown on its power consumption label, count on needing around 2,000 watts to keep your refrigerator cold and most of the lights on; 3,500 watts to add a window air conditioner; up to 7,500 watts to add a sump pump and furnace; and 20,000 watts to power most everything. To know how many watts you need in a generator, add up the wattage of the appliances or equipment you’re most likely to simultaneously operate. You can use this worksheet to help in your calculations. This number is only the beginning, however, because wattage consists of three components: the power to start an appliance, to keep it running, and to withstand a power surge—that moment when the regular juice starts flowing again and everything starts up. Many appliances require more power during startup compared with their running energy consumption. If you don’t factor in the starting watts, you may overload the generator as you start up appliances or other items. In the same vein, the generator may be overloaded from a power surge if the machine can’t supply enough wattage. So, depending on whether you are powering just a few items or the entire house, understand how much total wattage your generator can produce. Generally, increased wattage equates to an increased generator cost. But most people would agree it is better to have adequate power than to be left in the dark or have to decide between running your refrigerator or keeping cool with a fan.

Size

Home generators require space for installation, so factor in the size of any model you’re considering. The size of a generator ranges from compact units, with footprints less than 3 feet long, to large, liquid-cooled units that measure 5 feet or more in length. As a general rule, the more power capacity, the larger the generator. Also, keep in mind that model specifications and local codes may dictate how much clearance is required between the generator and your home. Some small generators require as little as 18 inches of clearance.

Fuel Source

Generators generally are powered by one of three fuel sources—gasoline, natural gas, or propane. Most portable generators are gasoline-powered and generally, can keep lights on and fridges running, but little more, for several hours. They can’t be depended on for longer-term backups such as when you expect power to be out for several days. Since these generators, as with most gasoline-powered machines, produce exhaust fumes and carbon monoxide, these should always be used outside your home, where there is adequate ventilation. You also need to take measures to keep gasoline stored properly for long periods of generator inactivity. A fuel stabilizer is one method of ensuring that the gasoline in your generator remains ready for use. Natural gas and propane are more commonly used for larger home standby generators. Generally, these fuels are considered cleaner-burning sources of fuel and provide on-demand sources of power. Natural gas generators need to be permanently connected to a home’s natural gas supply; the generator can operate as long as the gas supply remains uninterrupted. Propane generators operate like propane gas grills, with a liquid propane tank that connects to the generator. While a typical grill tank holds 20 gallons, tanks for propane generators run from 100 gallons (about 50 hours of operation) to 1,000 gallons (about 500 hours). Alternatives to fuel-powered generators are solar or battery-powered power sources. The capabilities and run times of these machines vary greatly, but they may be the right match if you have more minimal power needs—typically used for camping, not for home.

Warranties

The investment you make in a generator is often backed by a manufacturer’s warranty. Most residential portable and inverter generators are protected by a 2- or 3-year warranty period that covers parts and labor. Standby generators, which are generally larger investments, usually offer 3- or 5-year warranty periods. Some warranties also cover travel costs for a technician to come and service the generator, but this varies by manufacturer and model. Read the fine print closely to see what is covered.

Type

Decide which type of generator is best for your needs: a portable generator or a standby (or backup) generator. When doing this, determine whether you want just to keep the lights on, or whether you want to run other electrical components as well, such as computers, the refrigerator, and a window or central air conditioner. Portable generators are best suited for temporarily powering an appliance or two and smaller tools, or electric-powered items, like fans or lights. They typically operate using gasoline as their fuel source. (See “Fuel Source,” above.) For this reason, it’s crucial that you never operate a portable generator inside an enclosed space—including your house, garage, or shed. In general, portable generators make life more bearable during short power outages but don’t support all the creature comforts such as a central air conditioning system, water heater, and other large appliances. Inverters are a type of portable gasoline-powered generator that use less fuel and offer quieter operation by constantly adjusting engine speed to power only what’s using the energy load. Those machines have a higher price tags. For whole-home generators, a standby generator is the most common option since it offers average power outputs ranging from 10,000 and 24,000 watts. This type of generator is permanently installed outside the home and is connected to a propane fuel tank or natural gas line. With the addition of a transfer switch, standby generators are ready to supply power for a few hours or a few days or more thanks to a readily available fuel supply and high wattages. Standby generators come in air-cooled and liquid-cooled models. Air-cooled units, which use fans to keep engines from overheating, can well serve residential homes with average power needs. Liquid-cooled generators tend to be found in higher-wattage units, which homes in warmer climates rely on to run central air conditioner systems. In addition, liquid-cooled generators generally offer a quieter operation.

Standout Features

Automatic Start

Some whole home generators automatically kick in when the power goes out. This enables the generator to start supplying power to your home when it detects an absence of juice from the electric utility. Usually, this feature is found only on standby generators and not portables. The peace of mind that comes with knowing your generator automatically steps in to power without interruption vital systems, like a sump pump and heating and cooling system, may be worth the higher price tag that often comes with these systems. Note that this isn’t the same thing as an electric start, which powers up your generator with the push of a button rather than the recoil start typical of most small motor machines. In the case of a generator equipped with an electronic start, you still need to manually start the generator to begin the flow of power.

Transfer Switch

A transfer switch, connected to your home’s power box, automatically changes the power source from the electric utility to your backup. The system is designed to detect when the generator starts so your home can use its energy. The switch then disconnects your home from the power grid and supplies power from your generator to designated circuits in your home. This process happens seamlessly if your generator has an automatic start (see above), which engages the machine after it detects an absence of power from the electric company grid. We strongly recommend that a transfer switch be installed by a professional electrician. Never plug your generator into a standard electrical outlet—doing so can create electrical hazards, including back feed that can endanger utility workers that may be repairing power lines.

Why Trust The Spruce?

Erica Puisis has been covering home appliances and tools that make everyday life easier. With experience investigating the best home generators and portable generators and developing buying guides that help consumers make informed choices, she is familiar with the features that matter and the brands that offer reliable performance. To find the best home generators for this list, she considered factors like power output, size, fuel type, and cooling system. Most of the generators on this list are whole-home generators, but portable and battery generators are included for short-term supplementary power needs.

Portable generators require you to manually initiate the power transfer. Those products require different safety precautions, including the often-repeated advice to never operate the unit inside the home or garage; and never plug a portable generator into hardwired appliances or standard electrical outlets.

Generally speaking, a generator should be installed at least 5 feet from windows and doors. Some generators can be installed as close as 18 inches to the house, but you still need the 5 feet of clearance from air intake locations on the house.

Portable generators should never be used indoors, including in a garage. Instead, this type of generator should be positioned outside the home, with sufficient clearance from doors and windows—typically, 20 feet or more.

Perform a weekly self-test or run the generator for at least 30 minutes once per month. Most whole-home generators feature automatic self-test cycles that run for 15 minutes or less each week. For portable generators, you need to run the system manually. Doing so keeps the motor and components from seizing up and becoming prone to breaking or failure. Make sure that you only operate the generator in a well-ventilated, open area—even during these short maintenance runs.Add fuel stabilizer to the tank when storing a gasoline-powered generator for an extended period. This additive helps ward off corrosion, rust, and sediment. Gasoline that has gone bad is a leading cause of small engine failure, so don’t neglect proper fuel storage.Regularly repair or replace motor components that are subject to wear and tear. Items like spark plugs, air filters, fuel filters, and more can become worn over time.Never let the oil run low in your generator and perform regular oil changes. Doing so can cause major engine damage or even failure of the motor. Monitor oil levels and replenish as necessary. Many standby generators have a meter for engine hours to alert you to when it’s time for an oil change.