Best Whole-House Generators

There are four primary types of generators you should consider for emergency backup power: portable generators, inverter generators, standby generators and solar batteries. Identifying which type is right for your home is the most important decision you’ll have to make when purchasing a house generator.

Portable generators

Portable generators are the most affordable type, but they also have the least utility. These are likely what most people envision when they think about emergency backup generators. They typically consist of a gas motor on a wheeled frame that you can plug electronics into for emergency power. You need to start them manually to begin producing power.

Portable generators use internal combustion engines to generate alternating current (AC) electricity. Rather than storing electricity, they produce it as needed, so they typically power much less in real time than other types. They can provide emergency power for a refrigerator, freezer or small electronic devices, but they usually won’t support whole-home backup power.

On average, portable generators cost between $300 and $3,000, according to our experts.

Inverter generators

Inverter generators are similar to portable generators in that they use a physical, fossil-fuel-powered motor to produce electricity. The primary difference is that they also include an inverter, which converts AC electricity to DC and then back to AC. This helps generate more stable energy and allows the motor to operate at variable speeds based on demand.

“(Inverter generators) are the high-tech cousins of portable generators,” said Kristopher Evans, senior product manager at Briggs & Stratton Energy Solutions, a generator and backup battery company based in Wisconsin. “They use advanced electronics to smooth out the electrical current, (and) they are also much quieter, more fuel-efficient and lighter…than traditional portables.”

Inverter generators are more appropriate for sensitive electronics, like smartphones, smart TVs and laptops, which require a consistent power supply, making them more popular than portable generators for today’s electricity demands. They cost between $300 and $4,000, though, so they are more expensive on average.

Standby generators

A standby generator is one of the most popular options for homeowners looking for whole-home backup during power outages. These units are usually mounted on a concrete slab and are connected to your electrical system. They can automatically switch over to backup power in the event of an outage, creating a seamless transition without the need for a manual start.

Like portable and inverter generators, standby generators also use an internal combustion engine to produce power, but they more often use natural gas or propane for fuel since they’re permanent fixtures.

“The moment the local power grid goes down, (standby generators) turn on automatically within seconds, whether you are home or not,” said Evans. Since they don’t require manual starting, they’re one of the most popular options for whole-home backup.

However, they’re much more expensive than portable and inverter generators, costing between $10,000 and $25,000 for the equipment and installation on average, according to our experts.

Solar batteries

Another increasingly popular option is a solar battery, which isn’t technically a generator but can provide similar benefits. Rather than generating power, solar batteries store electricity that comes from a solar array or the grid. They’re most effective and affordable when you charge them with solar panels.

Most solar batteries can hold enough electricity to power your entire home through a blackout, and if you couple them with a solar array, you may be able to maintain a fully-powered home indefinitely at very low cost.

If you have solar panels, deciding whether you want a solar-powered home with a generator backup or a solar-powered home with a backup solar battery is a key decision to make. Relying entirely on solar will usually be more affordable overall, but coupling solar panels with a gas or propane generator usually provides greater peace of mind and doesn’t rely solely on sunshine.

A Tesla Powerwall, one of the most popular home solar batteries, costs an average of $14,300, including installation, making a solar battery one of the most expensive options. However, you won’t have fuel costs when you’re relying on your backup battery.

The average cost of a home generator ranges from $10,000 to $25,000, but your price will depend on many factors, including the type of generator you want, the output, the capacity, the brand and more.

You can use the table below to get an idea of what your home generator will cost, but you should always reach out to a professional to get a more accurate estimate for standby generators and solar batteries.

There are countless backup generators available, but you can narrow down your options and make sure you choose the type that works best for your home by considering the following factors.

Wattage

One of the most important things to think about when it comes to choosing a whole-house generator is the output capacity.

“A good place to start with is what you actually need to keep running,” said Cole Ashman, CEO of Pila Energy, a home battery backup company based in San Francisco, CA. “Most people immediately think about their whole house, but this can be cost prohibitive and isn’t an option for renters. When you really think about the essentials, it usually comes down to a few items for people: fridge, Wi-Fi, phones, a medical device (and) some lights.”

You can then take the total power you need in your home and use it to find a suitable output from an available generator.

“A generator's size is measured in watts, which is simply the amount of electrical work it can do at one time,” said Evans. “Sizing a generator incorrectly can ruin your appliances or damage the generator itself.”

You should think about running watts and starting watts when sizing your generator. Running watts provides the amount of electricity required to keep your appliances and devices powered once they’re on. Starting watts describes the initial surge of electricity your devices need to turn on. Starting watts are especially important for things like refrigerators and AC units.

A good rule of thumb for safety and adequate power is to take the starting watts of your appliances and devices and add them to the running watts of devices that don’t take a surge of power to start up, such as lights. You can base your required output on that total.

However, “the best way to determine the proper generator size is to have a qualified professional perform a load analysis and discuss your family's priorities,” said Evans. “Every home is different, and two homes of the same size can have dramatically different electrical requirements based on HVAC systems, appliances and lifestyle.”

Cost and pricing

Of course, upfront cost and ongoing cost are crucial factors when pricing your generator.

You can power limited appliances and electronics with a portable generator, which comes with the lowest cost of the different types. Portable generators usually cost between $300 and $3,000, and you don’t need professional installation.

If you want to power more sensitive electronics, like phones, laptops and smart TVs, consider paying more for an inverter generator, which will reduce the risk of damage to your belongings. However, this type of generator can cost as much as $4,000.

A standby generator is significantly more expensive than a portable or inverter generator, and it usually needs to run for an hour or two a week for maintenance, which can add to ongoing costs. Standby generators cost between $10,000 and $25,000.

Solar batteries will cost between $10,000 and $20,000 each on average, but you may need multiple batteries to support whole-home energy consumption.

Fuel type and capacity

You should always consider the fuel type of the generator you’re considering, as well as the capacity, as these factors can help you narrow down your options and decide on a generator that suits your demands.

First, think about fuel type. Portable generators usually run on liquid gas, allowing you to refill using a portable gas tank. Inverter generators also commonly use liquid gas but can also run on natural gas or propane, which requires less input from you. A tank with a higher capacity will last longer between refuelings.

Standby generators run on natural gas or propane, so they always have a fuel source and don’t require manual refueling. Solar batteries rely either on the grid or power from your solar panels and also don’t require refueling.

If your area experiences infrequent blackouts, a portable or inverter generator will likely be sufficient. However, if you see frequent power outages, a standby generator or solar battery is probably best for convenience, reliability and peace of mind.

Additional features

Many modern generators have additional safety and convenience features that you may want to consider when choosing one. It’s a good idea to upgrade to a generator with carbon monoxide detection and automatic shut-off capabilities, as these can make your unit safer to use.

Some manual-start generators also have electric starts, which make starting the unit significantly easier than it would be with a pull cord. This is a great feature to consider if you’re thinking of purchasing a portable or inverter generator that requires a manual start.

You can easily set up portable and inverter generators yourself with no experience, but the process of installing a standby generator is more complicated and requires help from a professional.

Here’s a breakdown of the process from start to finish:

• Permitting and site selection: First, your professional installer will figure out the best place to install your generator based on your property and the location of your electrical and gas or propane connections. They’ll also consider permitting requirements and costs before pouring a concrete foundation to house your unit.
• Plumbing connections: Next, “a licensed plumber runs a gas line from the home’s main natural gas meter or propane tank to the generator site to supply continuous fuel,” said Evans. The utility connections may require additional permitting costs, but they will allow your generator to run safely and legally.
• Automatic transfer switch (ATS) installation: Your pro will then install the ATS, which disconnects your home from the grid in the case of a power outage and defaults to your generator for power. This is a necessary component to keep electrical line workers safe.
• Final wiring and testing: According to Evans, your pro will then disconnect your home from the grid to simulate an outage and test for proper functionality to complete the installation.

Home generators need varying levels of maintenance, depending on the type of generator you choose.

Portable and inverter generators need the most maintenance. “The biggest killer of portable generators is old fuel,” said Evans. “Gas goes stale in about 30 days, creating a gummy residue that clogs the engine's fuel system. Homeowners must use a fuel stabilizer, run the engine every few months to keep parts lubricated and change the engine oil after every 50 to 100 hours of use.”

Standby units carry out their own maintenance but still require some input from you for proper functionality. “These units are designed to run a self-test automatically for 10 to 15 minutes once a week to keep the battery charged and fluids circulating,” said Evans. “However, they still require an annual professional tune-up to replace the oil, spark plugs and air filters, ensuring they are ready for a major storm.”

Solar batteries require no maintenance, largely because they just store energy and don’t produce it. “Because batteries don’t run on fuel, updates are done over the air via standard software updates, so it gets smarter and performs better over time,” said Ashman. “The technology’s app tells you if maintenance is ever needed.”

A whole-home generator provides power during blackouts and peace of mind during inclement weather, but it also comes with some important downsides to consider before committing. Make sure you think about all of the following upsides and drawbacks before you purchase or install a generator for your home.

A whole-house generator may be worth it for you if any of the following apply to you and your situation:

• You or a family member relies on medical devices that require constant power.
• You experience frequent blackouts or power outage threats in your area.
• You work from home and rely on electricity to remain connected.
• You live in an extremely cold climate where a power outage could quickly lead to frozen pipes.
• You live in a flood-prone area and rely on a sump pump to keep water out of your home.
• You rely on well water, and a power outage would also mean you don’t have access to water for drinking, cooking or bathing.