Home Standby Generator Buyer’s Guide: How to Buy the Right Generator

What is a home generator?

Anyone who lives in an area with frequent power outages can attest to the usefulness of a home generator. When the lights go out, a home generator will provide your home with power – and all the convenience and security that comes with it. If you’re on the market for a generator, this home generator buyer’s guide is for you. It will help you understand how a home generator works, what kind of generator is best for your home, and how much you can expect to pay for it. 

There are two basic kinds of generators: portable generators and standby generators. Portable generators are transportable and less expensive. While they can be used as a temporary backup power source, they do not last as long and typically cannot power your entire home. Standby generators, on the other hand, are a larger investment and cannot be transported, but they provide more consistent and long-lasting power to your home during outages. This home generator buyer’s guide focuses on standby home generators. 

Whether you want to buy a portable or standby generator, it’s important to understand your home’s energy usage before making a purchasing decision. How much energy you intend to use during an outage dictates the size or electrical output of your generator. Buying a generator that is too large or too small can damage your generator and appliances or cost you more money than necessary. To learn more about your energy usage, try using AlltimePower’s free Backup Power Calculator

The mechanics of a home generator

Home generators that run on a fuel source are a form of internal combustion engine. Similar to the engine in your car, a generator engine will convert the energy in a fuel source into mechanical energy. When a fuel source burns, expanding gases cause a piston to spin, which then turns a crankshaft. Ultimately, this mechanical energy forces the movement of electrical charges in a home’s wiring, which produces the energy needed to power your home’s devices. 

Fuel-powered generators run on natural gas, propane, diesel, or gasoline. Natural gas-powered generators can be connected to a home’s gas lines, which allows for more convenient and automatic access to power during an outage. Diesel-powered generators are the most common and most efficient fuel-powered generator. It’s a good choice for homeowners looking for the lowest-cost option available. 

Gasoline is a common source of power for portable generators, but it’s an inefficient and expensive option for backup generators. Because of its high volatility, it’s also difficult to store. Propane, which you may recognize by the metal cylinders it is stored in, is easier to store, but it is less efficient than gasoline or diesel. Regardless, it’s important to choose the best generator fuel source for your home before narrowing in on the generator of your choice. 

Alternatives to traditional standby generators

Fuel-powered generators are the most common choice, but they are not your only option. Some home generators run on solar energy through the use of rooftop solar panels. Solar-powered generators are clean and quiet, and they can help you reduce energy costs over time. Unfortunately, solar energy is generally not able to provide as much energy to a home’s appliances as traditional fuel sources, and they are more expensive to install. 

Another alternative to traditional, fuel-powered generators is a home battery backup system. Home batteries such as the Tesla Powerwall charge using power from the electrical grid. When the power goes out, the home battery uses the electricity it has stored to power your home’s devices. The result is a clean, quiet, and automatic source of energy that lasts anywhere from a few hours to a day. Some home battery systems can also be connected to solar power. That allows you to collect energy from the sun during the day to reduce utility costs or to use during an outage. 

Both solar-powered backup generators and home battery systems have advantages. Homeowners who are environmentally-conscious or want to find a quieter alternative to traditional home generators may prefer one of these options. Generally, neither of these alternatives can provide as much power as a fuel-powered generator. Homeowners who experience long power outages, such as those caused by natural disasters, may thus prefer a traditional generator. 

How much does a home generator cost?

Depending on the kind of generator you choose to install, the full cost of a whole-house generator for a medium-sized house is about $12,250 to $27,150 upfront, plus $165 to $485 per year in maintenance and repair costs. This includes the cost of the generator itself, plus the labor and material cost of generator installation. 

If this range is outside your budget, consider purchasing a portable generator instead. A portable generator can cost as little as $200. Alternatively, you can buy a partial-house generator instead of a whole-house one. A partial-house generator runs only some appliances in your home rather than all of them. For example, you may decide not to run your dishwasher and washing machine during an outage and instead direct all energy output to keeping the lights on and the air conditioning units working.

If you want to buy a partial-house generator, you'll need to decide which devices you most want to power. Next, you should calculate the size of the generator you would need to power them. You will also want to install a critical load panel, which will automatically power essential appliances, such as air conditioning or heating, while transferring power away from less important appliances. 

What size generator do I need?

Whether you decide to buy a partial- or whole-house generator will also impact the size (electrical output) of your generator. A larger generator will be able to provide more power than a smaller one, which in turn will mean you’ll be able to power more devices. To determine the ideal size of your generator, add up how much power it would take to power each essential appliance. 

When calculating the size of your ideal generator, it’s important to understand the difference between starting and running wattage. Starting wattage measures how much energy it takes to start a device, while running wattage refers to how much energy it takes to run an appliance once it’s been started. You want your generator to be able to both start and run your appliances, but since the starting wattage is higher than the running wattage for many appliances, you should focus on the starting wattage. 

Most devices include their starting wattage on a tag or in the owner’s manual. If you can’t find a device’s starting wattage, you can estimate it online. Next, add up the starting wattage of each device. This number will be the maximum amount of power you will want your generator to be able to supply. Also known as the generator’s peak load, this number is an important metric to keep in mind when shopping for a home generator. You can also find out your ideal generator’s peak load using our online home generator sizing calculator

Installation and maintenance

Choosing the right generator is only the first step in the process of purchasing a generator. You’ll also need to have your generator installed in your home. After a site survey and final purchase, your generator dealer will arrange a time with you to come to your home and install the generator. It may take two or three days to set up your generator, including the time it takes for professionals to connect your generator to your home’s electrical wiring and, if necessary, your home’s gas lines. 

Once your generator is installed, you’ll need to perform regular generator maintenance. This involves running your generator for a few minutes every week, regularly checking oil and coolant levels, and hiring a technician to perform a more detailed inspection every 6-12 months. Though it may be a pain, generator maintenance will ensure your generator will run when it’s needed, and it can increase the generator’s lifespan by decades. 

Finding the right home generator dealer

Once you know what kind and size of generator you want to buy, it’s time to find the right generator dealer. There are many generator dealers on the market, ranging from large retail or online companies such as Lowe’s or Home Depot to small, independent dealers. Given the investment involved in buying a generator, you’ll want to make sure the generator dealer you choose is reputable and affordable. 

Though most generator dealers you’ll find online are legitimate, some may be trying to scam customers. To avoid a scam, ask them to verify important information about generators on their site such as the serial number, brand, and size. You’ll also want to schedule a site survey and meet a representative before making a purchase. This will give you the chance to ask important questions about installation and your home’s individual needs. 

If you’re not sure where to start when it comes to choosing a generator dealer, you may want to use AlltimePower’s free, online generator service. After learning about your energy needs and generator preferences, we’ll match you with reputable generator dealers in your area. You will also have the opportunity for local dealers to bid to give you the lowest price.

Free Generator Estimate

Only takes 2-3 Minutes

Get Started