Most of our everyday lives are heavily reliant upon electricity. Residential and commercial generators provide backup power or whole-house power in the event of a power outage. Likewise, portable and inverter generators provide a main source of power to remote and mobile locations such as construction sites, RVs and boats.

Generators can be expensive depending on the type. Important things to consider when choosing a generator include size, output, capacity, fuel efficiency, noise level, technology and cost.

Top 10 Best Rated Generators

Founded in 1959 and based in Waukesha, Wisconsin, Generac makes power generators for industrial and residential markets. It rebranded its line of industrial generators in 2009 to include ergonomic and aesthetic changes.
Westinghouse was founded in 1886 and is headquartered in Monroeville, Pennsylvania. It designs and manufactures appliances including portable conventional and inverter generators for home, work and recreational use.

The ConsumerAffairs Research Team believes everyone deserves to make smart decisions. We aim to provide readers with the most up-to-date information available about today's consumer products and services.

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What features matter most in a residential or commercial generator?

How do you determine the correct generator size and output?

Determining the size of generator to buy comes down to which household appliances you want to power in the event of an outage. This will determine the kilowatt/watt capacity and the installation wiring of the generator, with most home standby generators being permanently connected.

  • Wattage: Generator manufacturers interchange the use of watts and kilowatts (one kilowatt equals 1,000 watts). A typical small- to medium-sized home needs a generator that produces around 3,000-8,000 watts, with larger, luxury homes and big businesses needing 50,000-200,000 watts.
  • Rectifiers: Newer generator models include a rectifier, which converts electrical output into smooth electrical waves, also known as sine waves. Sine waves are needed to power sensitive electronics like laptops, TVs and other high-end devices. Generators with rectifiers are more expensive but can be very efficient.
  • Single vs. three-phase: Single- and three-phase generators produce power differently, with a single-phase generator using one wave to produce power and a three-phase generator producing three separate waves of power, delivered in one sequence, ensuring uninterrupted power flow. Most residential power is single-phase power so most homes only need a single-phase generator, while most luxury homes and large businesses require a three-phase generator.

What types of fuel do generators use?

Generators generally use one of three types of fuel: gasoline, propane or diesel. Residential and commercial standby generators typically connect to the property’s fuel source to prevent the need to constantly refuel, while portable and inverter generators require manual filling.

  • Gasoline: Gasoline powers the majority of smaller, portable generators used for recreation purposes. They work by using a spark plug to ignite the gasoline and require manual refilling.
  • Natural gas: Natural gas is a popular option for home and commercial standby generators because you can connect them straight to the natural gas line that feeds into your property, eliminating the need to refuel your unit manually.
  • Propane/Liquid propane: Propane-powered generators are generally more expensive to operate because propane itself is more expensive than natural gas. However, you can get propane delivered to your home or use your home’s liquid propane line to provide continuous fuel flow.
  • Diesel: Diesel generators are preferred over gasoline because diesel engines are more efficient, producing more power at lower speeds. Diesel is cheaper and more fuel efficient than gasoline.
  • Dual-fuel: Dual-fuel generators are capable of using two types of fuel at the same time, using a governor that gradually adds the secondary fuel source until the optimal mixture is achieved for efficient operation.

How fuel efficient are generators?

It's always a good idea to know the estimated run time and how fuel efficient the generator you are interested in is, especially if it's one that requires you to refill the fuel supply manually. Many new generator models are fairly fuel-efficient, regardless of the fuel type. Large, standby units have technology that lets them maximize power and minimize fuel use.

  • Fuel efficiency: Natural gas and liquid propane are becoming the most popular types of residential and commercial standby generators because they are the most fuel efficient. Fuel efficiency will vary depending on the load it is operating under. For example, a natural gas powered 22-kilowatt generator will burn around three and a half gallons per minute on a full load, while a 38-kilowatt unit will burn around five and a half gallons per hour on a full load.
  • Load management: Some larger models of standby generators have load-management technology that lets them operate at maximum efficiency. Load management technology is designed to prevent too many high-current appliances from operating at the same time by automatically sensing if large appliances like and air conditioner or electric water heater should run or not.

How loud are generators?

The noise level a generator can produce is important. Whether you’re camping with a portable generator or at home when your standby generator kicks on, you’ll want a unit that runs smoothly and quietly. All generators are marked with a decibel rating, which is measured at an industry standard of 23 feet away from the generator.

  • Decibels: Most generators should run at or below 70 decibels (dB), which is about the equivalent of being in a car traveling 65 miles per hour. Most residential standby generators are designed to be quiet and produce about the same amount of decibels as an air conditioning unit (66-69dB).
  • Sound-reducing enclosures: Most new generator models use sound-reducing enclosures that keep units operating at around 65 dB for large residential and commercial standby units.
  • Inverter portable generators: If you are camping or near other people and need a quiet, portable generator, inverter generators are typically the quietest type because of the way they generate power.

What kind of advanced technology do generators use?

Modern generators have advanced features that make them more efficient, easier to use and maintain and more reliable than older models. From devices that automatically detect a power outage to a device that connects to cellular networks so you can use a mobile app to monitor your unit remotely, technology has made owning a generator relatively hassle-free.

  • Transfer switches: Transfer switches switch an electrical load between two sources. They are used with home and commercial standby generators to detect power outages and automatically switch the power load to the generator when one is detected. Once power is restored, it switches the power load back to the main source. Modern transfer switches can operate as fast as ten seconds of downtime in the event of an outage. Most companies sell them separately but require them for home and commercial units.
  • Paralleling systems: Paralleling systems are typically used for large businesses like hospitals, airports and data centers and work by synchronizing multiple generators to produce more power. Large boats use paralleling systems to connect multiple generators located in various parts of the vessel.
  • Low-oil shutoff: Most new generator models are equipped with low-oil shutoff capabilities. This prevents engine damage due to low oil levels.
  • Electric start with backup: Many portable generators are designed with an electric start, eliminating the need for a recoil rope starter, although those are still used as backups to the electric start.
  • Remote monitoring: Residential and commercial standby generators equipped with remote monitoring devices use wireless networks to relay operating data to a mobile app. Remote monitoring is popular with businesses so they can monitor their company’s power status.

How much does it cost to have a standby generator installed?

Most standby and whole house generators are installed as permanent fixtures outside of your house on a concrete pad, similar to an air conditioning unit. Standby generators that power your main appliances in the event of an outage cost less to install than whole house generators that power your entire house.

  • Standby generator: A standby generator is intended to power your main appliances in the event of an outage. Small to medium -sized standby generators cost around $500-$1,000 to install.
  • Whole-house generator: Large generators that power your entire home when the power goes out typically come with an installation fee of around $3,000-$5,000.
  • Additional costs: Some additional costs to consider before having a generator permanently installed include the concrete pad that the generator sits on, as well as the transfer switch. Transfer switches cost around $200 and must be installed in your power-inlet box by a professional electrician.

What are the different types of generators?

Home standby generators

Home standby generators sit close to your home like an air conditioning unit and hook up to your property's electrical system and natural gas source. They are connected to a transfer switch which lets the generator know when your home loses power and automatically turns it on seconds later. Home standby generators come in various sizes and output wattage depending on the size of your home and how many appliances you need to power.

Commercial standby generators

Commercial standby generators are similar to home standby generators but on a larger scale. Commercial models can use paralleling systems to connect multiple generators and provide more power from a single line.

Single vs. three-phase generators

Single- and three- phase generators provide power differently. Both types provide alternating current (AC) power, but a three-phase generator produces three separate waves of power, delivered in one sequence, ensuring uninterrupted power flow. Most residential power is single-phase, therefore requiring only a single-phase generator. Large businesses like hospitals, airports and data centers require three-phase systems.

Inverter generators

Inverter generators produce direct current (DC) power and convert it to alternating current (AC) power. This process creates a smoother electrical current, which is a more stable and safer for electronic devices.

Portable generators

Portable generators are light enough to carry or have a built-in set of wheels to make them easier to move to different locations. Small portable generators are mainly used for recreational purposes, while larger, industrial portable generators are used to power remote work sites.

Who would benefit from a generator?

Homeowners

Home standby generators provide a sense of comfort knowing your home will still maintain power in the event of a power outage. Most home standby generators can be hooked up to your home’s fuel source and installed with a transfer switch to kick on within seconds after you lose power.

Businesses

Businesses with backup generators will never lose revenue due to lost productivity or downtime during a power outage. Essential businesses like hospitals, airports, data centers or government facilities will never have to worry about not being able to perform critical tasks when the power goes out.

People with RVs and campers

If you own an RV or camper, a portable generator can power your appliances like TVs, electric grill, satellite receiver, portable fan or radiant heater.

People who host outdoor events

If you like to entertain or host events outdoors, a portable generator will allow you to power outdoor lights, heaters, fans and more.

Boaters

Boat owners use portable and backup generators to power their boat’s electric supply. Larger vessels can use multiple generators hooked up together to create more wattage from a single line.

Generator company reviews

  • Generac Power Systems

    For over 50 years, Generac has been making residential standby generators. Today it also makes portable and industrial generators, fully automatic transfer switches and accessories for backup power applications. Consumers can choose from multiple fuel types for their generators and many different series and models based on their specific needs.

    • Best for homeowners or property owners wanting reliable backup power.
  • Briggs and Stratton Generators

    Briggs and Stratton has been manufacturing gas-powered engines for everything from lawn mowers to race cars since 1908. Today, it uses its engine technology in its line of portable, home standby, inverter and commercial standby generators. Their generators boast innovations that reduce noise, improve efficiency and are easy to use.

    • Home standby generators: Briggs and Stratton offer multiple series and models of home standby generators to ensure your home maintains power during storms or unforeseen circumstances. It has 15 models of home generators in four series: Fortress, Managed Whole House Power, Selected Circuit and Whole House Power series. Home generators are equipped with oil warmers to ensure they maintain power during cold temperatures. Home standby generators include commercial-grade engines that range from 12-60 kilowatts per hour.
    • Commercial standby generators: Briggs and Stratton have 11 models of commercial generators that are designed to handle power outages at your business or luxury home to reduce downtime and lost revenue. Models range in output from 35-200 kilowatts per hour and are equipped with a customized transfer switch to automatically switch critical power from the generator to the business or home. Commercial generators come with a three-year or five-year parts, labor and travel limited warranty.
    • Portable generators: Briggs and Stratton manufactures over 20 models of portable generators designed to power your home, backyard or outdoor adventure vehicles and devices. Portable generators come in four series that offer differing wattage: Elite, PowerSmart, PRO and Standard series. Depending on the intended use, you can find a portable unit with an output as low as 2,000 kilowatts or up to 10,000 kilowatts.
    • Inverter generators: Briggs and Stratton has three models of inverter generators that range in output from 2,000-3,000 watts. These models are designed for camping, tailgating and similar recreational activities and have USB adapters, are safe for sensitive electronics and are parallel capable, meaning more than one can be hooked up together.
    • Pricing: Prices for Briggs and Stratton generators are not listed on their website, but you can use their website’s dealer locator to find the closest dealer.
    • Best for consumers looking for a portable, home or commercial generator.

  • Westinghouse

    Westinghouse got its start over 115 years ago, patenting the rotary steam engine. Throughout the years it has designed and manufactured multiple consumer appliances such as energy efficient light bulbs, LCD TVs and conventional portable and inverter generators. Its generators are designed for powering home appliances in emergency situations, campers and RVs and industrial job sites.

    • Best for consumers needing a portable generator for travel or recreational purposes.
  • Honda Generators

    Honda is known for its design and manufacturing of large and small vehicles and power equipment. Additionally, it makes a line of portable, inverter generators for home, work and recreational use that can power anything from common household appliances to industrial motors. All generator models designed by Honda are made to be used with regular unleaded gasoline. For a safe and easy-to-use experience, Honda recommends installing a transfer switch before using its generators.

    • Portable-power generators: Honda’s portable-power generators offer homeowners a backup power source to keep common household appliances running in the event of a power outage. You can choose from over 20 models ranging in power output from around 2,000-7,000 watts and run-times ranging from approximately eight hours per gallon of gas to over 20 hours for every 3 gallons of gas.
    • HP2S: HP2S is Honda’s universal transfer switch that can be installed by an electrician to work with any Honda generator. It works by automatically switching to an installed battery upon a loss of power, to provide power while you start your generator. Once you move your generator outside and start it up, you plug it into the universal transfer switch (HP2S). Once your power comes back on, the HP2S will automatically switch back to utility power.
    • Power management: Honda helps you calculate how much power you will need from a generator for home, recreational or industrial needs. You can check their website for a detailed explanation for each category but a typical small home will need around 3,000-5,000 watts with larger homes needing around 5,000-6,500 watts. Campers, tailgaters and boaters will need around 1,000-2,000 watts of power to handle their needs.
    • Industrial generators: Honda helps you decide which generator is right for your industrial needs by asking how many tools you will be powering at one time. A single tool will require around 2,000 watts (120-volt tool), two tools will need around 3,000-4,000 watts (120-volt tools) and multiple tools need 4,000 plus watts depending on the voltage of the power tools.
    • Pricing: Honda lists the pricing for all generator models online. Prices vary depending on multiple factors like wattage and engine type but its generators range from $949.95-$5,399.05 MSRP.
    • Best for consumers needing a portable generator for home and recreational use.

  • Yamaha Generators

    Yamaha has been designing and manufacturing a wide range of products for over 130 years, including musical instruments, electronics and power sports equipment. It began making generators in 1973 and today offers 14 models of inverter and premium-grade industrial generators.

    • Inverter generators: Yamaha’s line of inverter generators includes eight models ranging in output from 1,000-6,300 watts. Models come with varying special features, but most include a fuel petcock to prevent stale gas and gummed-up carburetors, a smart throttle that changes speed based on load and an oil watch warning system that prevents engine damage caused by low oil levels.
    • Industrial generators: Yamaha has six models of premium-grade industrial generators that range in output from 2,600-12,000 watts. These industrial, portable generators are ideal for camping, tailgating and other outdoor activities, as well as running home appliances in emergency circumstances. Most industrial models can provide around eight hours of power on a single tank of fuel. Yamaha includes an online chart under each model that shows the capabilities and applications of each unit.
    • Included accessories: Yamaha includes free generator oil, fuel protection and shipping on all of its generators. Orders received by 12:00pm CST will ship on the same day.
    • Warranties: All Yamaha generators come with a three-year limited warranty with the option of adding up to six years of an extended warranty at an additional cost.
    • Pricing: Prices for the inverter generators range from $791.10-$3,689.10 depending on the output capacity. Prices for the industrial models range from $749-$3,959.10 depending on the output capacity.
    • Best for consumers wanting a portable generator for tailgating or outdoor activities.

  • Kohler Generators

    Kohler can trace its roots back to 1873 making cast iron castings. Today, along with plumbing fixtures, engines and furniture, it manufactures multiple models of industrial, home, portable, mobile and marine generators. Kohler generators can be fueled by natural gas or diesel and can be used to power anything from campers, boats and RVs, to large businesses and data centers.

    • Gas generators: Kohler designs and manufactures over 100 customizable gas generators for light commercial and heavy industrial use. They are designed specifically for standby, prime or continuous power applications and can run on fuel, dual-fuel, natural gas or propane. A full list of gas generator models and specifications are available online.
    • Diesel generators: Kohler’s diesel-fueled generators are designed and built to power large businesses such as hospitals, data centers, gas stations and airports. Models that are fueled by diesel range in output from 100-4,000 watts with their newest line of KD series diesel generators producing up to 4 megawatts of power. A full list of models and specifications is available online.
    • Paralleling systems: Designed for large businesses and data centers, Kohler’s Decision-Maker Paralleling System offers 100 percent integration into your current utility setup. Whether you just need emergency backup power or prime power, Kohler can customize a system to fit your business’ needs. The paralleling system uses multiple generators (up to 9+) to provide enough power to run large facilities.
    • Marine generators: Using a variation of the Decision-Maker paralleling system, Kohler lets you pair two or more generators with a single communication wire. This allows boat owners to place a generator in the starboard and port side, as well as a nighttime generator in the back, all connected to one switchgear.
    • Sizing program: Kohler has a sizing program app called “Power Solutions Center” that you can download on your PC or mobile device. Its easy-to-use features like drag-and-drop, automatic one-line diagrams and pre-populated engineering tools let you spec and size your power system on the go.
    • Best for large businesses, data centers, hospitals and airports.

  • Champion Power Equipment

    Since its beginning in 2003, Champion Power Equipment has expanded from its California base and opened locations in Tennessee, Wisconsin and Toronto. It has also expanded its product line to include portable, inverter and home standby generators for work, home and recreational use. Champion’s generators can operate using gas, propane or dual-fuel and include either a pull or electric start or wireless remote start.

    • Home standby generators: Champion offers two models of home standby generators, giving your home a permanent backup power source. They connect to your Liquid Petroleum Gas (LPG) or natural gas system so you never need to refuel it. You can choose from an 8.5- or 12.5-kilowatt model. Transfer switches are sold separately.
    • Inverter generators: Champion has 18 models of inverter generators, including gas, propane or dual fuel options, as well as pull-, electric- or wireless remote-start options. Their output range of 1,000-4,000 watts, coupled with their lightweight portability, makes Champion’s line of inverter generators optimal for RV and tent camping, hunting and fishing needs and events.
    • Industrial generators: Champion’s industrial generators are designed to be portable and durable to make working on remote job sites like farms and construction easier. It has over 60 models of industrial generators ranging in output from 1,000-12,000 watts. They can be fueled by gas, propane or dual-fuel and have a pull-, electric- or wireless remote-start.
    • Dealer locator: Champion does not sell all of its products directly to the public. They offer an online dealer locator to help you locate power equipment and home standby generators.
    • Installation costs: Champion offers installation for their two models of home standby generators. A Champion dealer will give you an exact quote based on your needs, however, installation costs are additional and generally run around $2,000-$3,000 for a home standby unit.
    • Best for consumers wanting an industrial or portable generator.

  • Honeywell Generators

    Honeywell manufactures consumer products like thermostats, sensors, security alarms and dehumidifiers. It also designs and makes a line of backup power generators for home, commercial and recreational use. Honeywell’s generators run on natural gas, diesel or propane and can be a single- or three-phase model depending on the size of your property.

    • Home backup generators: Honeywell manufactures over 25 models of home backup generators that range in output from 7,000-150,000 watts. They hook straight into your home’s fuel source so there’s no need for refueling, and they come with a premium two- to five-year limited warranty. Honeywell provides an online calculator and a free, in-home assessment to help you decide which generator is the right size for your property.
    • Commercial generators: Honeywell’s line of commercial backup power generators includes 15 models ranging in output from 15,000-130,000 watts. Each model comes with a two-year limited warranty, an external viewing window and RhinoCoat aluminum casing to protect against all types of weather. Honeywell’s commercial models include a feature called WhisperCheck, which runs a weekly self-test at a low RPM to make sure it is in working order.
    • Portable generators: Honeywell offers eight models of inverter and conventional portable backup generators with output ranging from 1,400-7,500 watts. Each model comes with a two- to three-year limited warranty, push-button electric start and a low-oil shutdown feature that protects against engine damage due to low oil levels.
    • Mobile Link: Mobile Link is a cellular remote monitoring device and app that lets you receive and share information about your generator system from any mobile device. Most home and commercial generator models come with this device, which uses cellular networks to send data as opposed to Ethernet connections like some generator models.
    • Transfer switches: Automatic transfer switches monitor your home’s utility power and automatically kick on within seconds of an outage. Choosing the right transfer switch depends on what items you want to supply power to. Honeywell will help you determine which transfer switch is appropriate for your home based on your power load.
    • Best for consumers needing a backup power source for their home, business or RV.

  • All Power Generators

    All Power is based in North Carolina and manufactures and distributes power equipment worldwide. Its products include engines, pressure washers, lawn mowers, snow blowers and portable generators. Its line of portable generators include 15 models that are powered by either gas, propane or diesel.

    • Gasoline generators: All Power’s line of gasoline-powered generators have a power output ranging from 1,300-8,000 watts and a one- to eight-gallon fuel capacity. Each gasoline model comes with a low-oil shutdown feature to prevent engine damage from lack of oil and wheel kits to make transportation easy and convenient.
    • Diesel generators: All Power’s diesel generator models produce a power output ranging from 6,500-7,000 watts and run-times around 11 hours when running on half of a load. Each model includes an electric start and a recoil back-up start.
    • Propane generators: All Power’s propane-powered models have a power output ranging from 3,500-10,000 watts and an eight-hour run time when running on half of a load. Each model includes a propane hose, mobility kit and either a 420cc engine, six and a half horsepower engine or a 13 horsepower engine.
    • Product registration: All Power includes an online form to fill out for product registration, including your product’s model and serial number. Proof of purchase will be necessary for all warranty claims.
    • Support and service: All Power includes a support and service page on their website that allows you to submit a ticket to their support team, access a knowledgebase of articles, manuals and FAQs, and read about company news and products. Additionally, you can find email addresses for support, sales and new orders, as well as the company's mailing address.
    • Best for consumers needing a portable generator.

  • GE Generators

    GE designs and manufactures products across many sectors, including power and water, oil and gas and aviation. It is also a common brand for consumer power products and appliances. Its line of standby generators and transfer switches are designed to provide backup power for home and commercial needs.

    • Residential generators: GE’s line of residential generators includes nine models ranging in output from 8,000-60,000 watts per hour. The smaller models can power small properties with low natural gas pressure come with a comprehensive five-year warranty. The larger models have the Symphony II power management feature, which allows you to manage where power is directed to help you power your entire house with lower wattage. Large home models also include a five-year limited parts and labor warranty.
    • Commercial generators: GE’s commercial-grade generators come in six models ranging in output from 35,000-62,000 watts per hour and include single- and three-phase units. All commercial generators come with a five-year limited parts and labor warranty, a low oil pressure shutdown feature, remote monitoring and can run on natural gas or liquid propane.
    • Transfer switches: GE includes transfer switches with each model of home standby generator. There are three different types of switches for different sized homes: 50, 200 and 400 Amp. Small properties can use a 50 Amp switch while larger properties with larger generators need the larger transfer switches. Once you know how big of a generator you need, you can get a transfer switch that matches that generators wattage output.
    • Sizing calculator: GE includes a sizing calculator online to help you determine the correct size generator for your property. It includes all essential appliances, allowing you to select any additional high-wattage appliance you may wish to power in the event of an outage.
    • Pricing: GE lists all pricing for its home standby generators online. They range in price from $2,199-$17,999. Commercial generator pricing can be obtained upon request.
    • Best for consumers needing residential or commercial backup power.