Standby Generator FAQ

If you’re in the market for a standby generator, you may be overwhelmed by the amount of information to consider. From the generator’s size and fuel source to its installation location and maintenance plan, there are a lot of factors to consider when buying a generator. Our experts have compiled some of the most frequently asked questions in this standby generator FAQ and answered them to help you make the right decisions when it comes time to buy a generator.

What are the benefits of a standby generator?

A standby generator provides electrical power to your home during a power outage. Unlike a portable generator, which must be manually connected to a home’s electrical circuits during an outage, a standby generator is wired directly to your home’s electrical circuits during installation. When the lights go out, the standby generator automatically kicks in, restoring power to your electrical appliances. This means you and your family can enjoy the security and comfort of knowing you will have a continual supply of power, even during an emergency.

Standby generators have advantages beyond safety and comfort. For example, extended power outages may cause food spoilage and water damage, which can cost a lot of money. In some instances, power outages could also cause loss of income if the homeowner works from home. In cases where in-home medical equipment is in use, a standby generator could even mean the difference between life and death.

Therefore, a standby generator is most likely worth the investment if you live in an area that experiences frequent power outages or is prone to natural disasters. Humans depend on electricity for many aspects of their lives, and an extended interruption to that power supply can have serious consequences. Standby generators give you and your family peace of mind so that when the next power outage strikes, you are not left without power.

What should I consider when buying a residential standby generator?

Not all generators are the same. Before you buy a generator, you should consider these five key factors:

Fuel source. Standby generators can be powered using natural gas, propane, or diesel. Choosing the right generator fuel involves balancing cost, availability, and personal preference. See below for more information.

Power output. Standby generators vary based on how much power they are able to produce. You should choose a generator based on the maximum wattage your appliances will need to start up and operate.

Cost. Standby generators have a large price range, depending on the power output, fuel source, and manufacturer. As a general rule, the larger a generator, the more it costs. Additionally, generators that run on multiple fuel sources are more expensive than other types of generators.

Location. You will also have to consider where on your property the generator will need to be installed. Work with your installer to find a location that is out of the way but still able to be connected to your home’s electrical circuits.

Maintenance. Before you buy a generator, you should be aware of how much time and money you will have to put into maintaining it. Standby generators need to be run about once a week for 30 minutes to keep the engine healthy. You should also have a technician perform a detailed inspection of your engine every 6 to 12 months.

What is the best fuel source for a standby generator?

The best fuel source depends on your individual needs and preferences. Diesel-fueled generators are generally the most reliable, have the longest operational life, and are the least expensive to maintain and operate. However, diesel-powered generators have disadvantages too. They are less environmentally friendly and noisier to run than propane- or natural gas-powered generators. Depending on where you live, diesel-powered engines may be subject to restricted runtimes for environmental reasons.

If convenience is your primary concern, you’ll want to choose the most readily-available fuel source. For instance, if you already have natural gas service from your local gas utility, a natural gas-powered generator that is directly connected to your pre-existing gas lines is probably the best choice. Likewise, if you have a propane tank on your property for heating or cooking, you will likely want a propane-powered generator. Diesel is stored in individual containers and can be purchased at locations across the U.S. For more information on generator fuel options, check out this blog post.

How do I know what power output (a.k.a. size) I need from a standby generator?

Determining a generator’s power output, or size, is one of the most important aspects of choosing a generator. A generator’s size decides what appliances in your home you can run during an outage. The size you need depends on the peak load your generator will need to power all the appliances you want to power. The peak load is the sum of all of the individual appliance loads that would be running simultaneously when your generator is powering your home.

When calculating the peak load, you’ll want to focus on how many watts it takes for an appliance to start up rather than run. For example, if you want to run your refrigerator and hot water heater on your generator, and your refrigerator takes 1200 watts to start and your hot water heater takes 4500 watts to start, you’ll have a peak load of 5700 watts (5.7 kilowatts). That means your generator will need to have a size of at least 5.7 kilowatts.

Of course, many homeowners want to run more than two appliances, so the peak load would likely be higher. Some homeowners want unconstrained use of power during an outage. This is called “whole-home backup,” and it requires a larger and more expensive generator than if you only want to power certain appliances.

You can limit your power usage to crucial loads by switching the circuit breaker for non-critical loads to the off position during an outage. To ensure the most important appliances have enough power to start up, you may also want to install a critical load panel. Regardless, it’s important to determine your peak load before you buy a generator. You can do this by adding up your appliances’ individual loads yourself, or you can estimate your peak load using our generator sizing calculator.

How do I determine my peak load?

To determine your peak load on your own, make a list of all of your appliances and their respective levels of power consumption in kilowatts. If you are unsure of an appliance’s peak load, check the owner’s manual, or look online for an estimate. Be sure to include any appliance you’ll have powered on during an outage. This could include larger power consumption items such as your heating, ventilation, and air conditioning system, any sump or well pumps, dishwashers, clothes dryer, etc., as well as any smaller loads such as LED lighting, toasters, hairdryers, and so on.

Add up the power consumption value of each appliance. Use the starting wattage rather than the running wattage because the starting wattage will be higher. Multiply the consumption of anything that contains an electrical motor by three to account for inrush current. The number you come up with will be an estimate of your total power consumption. If this is too complicated, or if you want to double-check your calculation, feel free to use our free generator sizing calculator to help you determine your peak load.

What happens if I overload the generator?

Overloading a generator occurs when the appliances relying on the generator demand more energy than the generator can produce. As a result, the generator’s demand is overloaded, causing it to malfunction and potentially leading to internal damage. It’s more common for older generators, but any generator may suffer from overload when its energy demand is exceeded. Signs that your generator may be overloading include overheating, unexpected power reduction, and leftover soot in the generator’s exhaust.

To prevent generator overload, it is important to buy a generator that is the correct size for your home’s energy consumption level. If buying a generator that covers the maximum output of your home is outside your budget, be aware of which appliances you choose to run during an outage. Some generators are also protected by circuit breakers, which prevent the generator from experiencing excess demand.

What is a critical load panel?

Another way to prevent overload is by purchasing a critical load panel. A critical load panel is a piece of equipment, usually a small box attached near your home’s main circuit panel, that controls which appliances receive power from the generator during an outage. Not all homeowners who purchase a generator choose to install a critical load panel, but those who do use it to ensure certain appliances, such as air conditioning or heating, have enough power to start up and run. Items not connected to a critical load panel will not be powered when the grid goes down, giving more power to the appliances that are connected.

A critical load panel can add a few hundred extra dollars to your investment; however, it can help you save money by allowing you to buy a smaller generator and use less fuel during an outage. If you care primarily about running only a few appliances, then installing a critical load panel may be the best option for you. If you would rather install a whole-home backup generator or choose which appliances to run manually, then you probably do not need a critical load panel.

What is a soft-start module?

Another way to reduce the size of the generator you need is by buying a soft-start module. A soft-start module connects to your air conditioning compressor to enable it to start without requiring inrush current to be provided by your generator. In other words, it allows the air conditioning system to start up without using as much energy. A soft-start module requires some additional cost to purchase and install but enables you to get by with a smaller generator and less fuel consumption during outages.

What does a standby generator cost?

Buying and installing a standby generator costs anywhere from $6,000 to $20,000 or more. If this is outside your budget, you might consider a gasoline-powered portable generator. Small portable generators cost just a few hundred dollars, but they do not start automatically. Instead, they must be plugged into directly with an extension cord or connected to the home’s main circuit panel with a manual transfer switch. They generally do not provide enough power to cover more than a few essential items.

For more information on the real cost of a generator, read this blog post. You can also use AlltimePower’s backup generator pricing tool to learn how much you can expect to spend on a generator based on your home’s individual power needs. Once you price the generator you will need, you can opt to have independent dealers bid to give you the lowest cost.

What does it cost to operate a standby generator?

Buying and installing the generator is the largest chunk of your investment, but you’ll also need to pay a few hundred dollars a year in fuel, maintenance, and repair costs. Typical fuel costs range from around $30 per day for a natural gas generator up to around $100 per day for a diesel generator. These numbers can vary significantly depending on your average load and fluctuations in fuel costs over time.

Of course, you’ll only need to pay for fuel by the day during a power outage. During the rest of the year, you’ll spend only a little on fuel costs to run the generator each week. It costs no more than $10 to run a generator for 30 minutes on natural gas. Maintenance and repair costs will likely add around another $200 or more per year.

How do I select a location for my generator?

Finding the right location for your generator is important to do before you have it installed. You should discuss the best location for it with your installer. Many homeowners do this when the installer comes to the home to give an installation price estimate. Even so, it’s important to understand some of the most common concerns so that you and your installer can make the best decision on where to install it.

Your first priority should be to make sure the generator is installed in a location that optimizes its output. It must be connected to the fuel source, whether it be a natural gas line or a propane tank, and to the main circuit breaker panel. You should find a location that minimizes the electrical wiring and gas piping costs, but also be aware of how the generator’s location will impact you and your family. You’ll probably want to keep the generator in a location that is not frequented very often.

Also keep in mind that the generator will create some noise, so it might be smart to install the generator away from bedrooms or other living spaces you want to keep quiet. These choices could also impact the value of your home if you ever choose to sell it. Finally, you and your installer should discuss any clearances or other factors required by code. Some areas may limit how close to another home you can install a generator. If you have a small yard in a dense neighborhood, it may not even be possible to install a generator without breaking a code, so it’s important to be aware of any codes and regulations before you commit to purchasing a generator.

What is involved in maintaining a standby generator?

Once you install a standby generator, it may be tempting to forget about it until the next power outage. To keep the generator in good, working condition, however, it’s important to perform some maintenance. Standby generators should be run each week for 30 minutes. Running a generator is somewhat noisy, similar to running a gasoline-powered lawn mower, so keep that in mind when selecting the location for the generator on your property and when scheduling maintenance runs.

When running your generator, you should check to make sure it has adequate fuel levels and no fuel leaks. You’ll also want to check oil and coolant levels about once per month. Every 6 to 12 months, you should hire a technician to perform a more detailed inspection. Most dealers offer service contracts for around $200 per year. For more information on generator maintenance, read this blog post.

How many years will a generator last before it has to be replaced?

The lifespan of a generator depends on a number of factors, but you can expect your backup generator to last about 20 to 30 years, or 10,000 to 20,000 run hours. To increase the lifespan of your generator, be sure to avoid overloading it, as this could damage the engine. Running your generator every week and hiring a technician to perform routine maintenance checks will also help the generator last longer.

If your generator is on the older side, you’ll want to watch out for warning signs that it may be time for a replacement. If you are having trouble starting your generator or if the generator provides inconsistent power (i.e., you notice the lights flicker while running on the generator), the engine may be wearing out. Higher levels of carbon dioxide emission and higher fuel costs are other signs that it is time to replace your generator.

What is the difference between an air-cooled and a liquid-cooled generator?

When purchasing a generator, it’s important to keep in mind what kind of cooling system you want your generator to have. All generators heat up while running. Without a proper cooling system, a generator may suffer permanent damage from the heat. For this reason, generators come with either an air-cooling or a liquid-cooling system.

The type of cooling system a generator has depends on its size. Smaller generators use an air-cooling system, which uses fans to force air through the engine, cooling it as a result. They tend to be less expensive and easier to maintain. Larger generators, however, may produce more heat than an air-cooling system can manage, meaning they would require a liquid-cooling system. Liquid-cooled generators contain enclosed radiator systems for cooling. They are more expensive and require more maintenance.

How long does standby generator installation take?

Most home backup generators take about one day to install, or possibly two for especially large generators. If you want to install a concrete pad on which to put the generator, installation may take two to three days in total. It will also take a few days to obtain the necessary permits before the technician arrives to install the generator. Remember that during installation, the technician will need to shut off the power in your home for several hours.

Can I install a backup generator myself?

No, you should not install the backup generator unless you are a certified electrician. Installing a generator involves wiring it into your home’s electrical circuits. Unlicensed operators risk serious injury or death, or may end up causing damage to your home’s electrical system. Instead, you should choose a licensed installer with experience installing generators who offers a warranty.

Can a standby generator replace utility service?

It is generally a bad idea to try to replace your utility service with a home backup generator. Trying to power your home yourself would likely cost you much more in fuel costs than buying from the utility company since their power is distributed among thousands of customers. Trying to run an emergency backup generator endlessly would also require a lot more maintenance and lower the lifespan of the engine. In general, home backup generators should be used only in emergencies.

If you want to live entirely off-grid, you’ll need to buy a prime power generator or continuous power generator. These tend to be significantly more expensive than emergency generators, but they are specifically made to be able to run for long periods of time. For more information on going off the grid, read our blog post on the subject.

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