The 7 Best Home Generators of 2023

What to Look for in a Generator

Wattage

The watts produced by a generator quantify the generator's ability to power whatever is plugged into it. This is one of the most important things to know about any generator you’re considering.

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.