On a quiet winter evening, residents in Northern Massachusetts settle in for a peaceful night. The street lamps make the freshly fallen blanket of snow sparkle under their glow, and warm light spills from the windows of homes where families are tucking in for the night. At this moment, everything feels perfect.
But overnight, as temperatures drop and the winds pick up, the gentle falling flakes turn into fast-moving sheets of snow. Tree branches sway back and forth, some giving way to the weight of the snow and the force of the winds, and the peaceful night has suddenly turned into a full-blown winter storm. As ice coats the power lines, a sudden flash gives way to complete darkness! The entire street, as far as you can see, has lost power. With a storm this powerful and no end in sight, the worry sinks in: when will your power be restored?
Power outages are much more than inconveniences. Losing power does more than cause minor disruptions in daily life; it can spoil food, leave homes without heat or AC, and create significant safety issues in extreme weather. With a home generator, crucial systems and appliances can continue to run, protecting sensitive electronics and preventing frozen water pipes. Most importantly, a backup generator provides residents with safety in potentially dangerous circumstances.
In this guide, we’ll explain the basics of home generators, the different types of generators available, and the various sizes, along with the purposes of each. For those who aren’t familiar with generators, wattage, and other details of backup power, we’ll cover how to pick the right size for your home’s needs to deliver optimal performance and safety when the power goes out.
Why Consider a Home Generator?
If you have ever experienced a nor’easter rolling off the shores of Lake Michigan, you probably already know why they’re helpful. But for those that need a reminder, home generators supply electricity to your home when the main power utility fails. By automatically restoring power almost instantly after the power goes out, home generators provide homeowners with comfort in circumstances that would otherwise feel stressful.
Many factors, such as severe weather, equipment failures, or unexpected outages, can cause power failures. It’s during these times that a whole-home generator really shines, providing access to heat, lighting, refrigeration, and other essential home systems. Having a generator installation with an appropriately sized generator can help a homeowner:
- Keep living spaces comfortable and livable during power outages.
- Keep food from spoiling and save money by preventing loss of refrigerated or frozen items.
- Protect essential systems such as sump pumps, security systems, and HVAC systems, and keep them functional.
- Power medical equipment (if used).
- Protect sensitive electronics and appliances during power loss.
Because power outages can last anywhere from hours to days, especially during the winter, having a reliable backup power source is extremely valuable. With modern generators being cleaner, quieter, and more efficient than ever, whole-home systems are a realistic option for many Northborough households.
Types of Home Generators
Backup generators come in a wide variety. Most residential generator systems fall into two general categories:
Portable Generators: True to their name, portable generators are small in size and not stationary. These generators are mobile and have to be set up manually during a power outage. These units are affordable and run on fuels such as gasoline, diesel, natural gas, or propane. Portable generators help run only a few essentials, such as refrigerators, lights, or sump pumps, and are a budget-friendly option that does not require a whole-home generator installation. However, if not used with proper ventilation, these generators present a carbon monoxide hazard. Best for occasional use or camping, portable generators are not a complete and safe solution to powering an entire home when the power goes out.
Standby or Whole-Home Generators: This type of generator system is fixed in place and connected directly to your home’s electrical box. Generators resemble an air-conditioning unit and are connected to a permanent fuel reservoir. These generators are powered by diesel, propane, or natural gas and automatically turn on when power is disrupted, supplying the entire house with power during an outage. Because standby generators are connected to the electrical box and power up automatically to run the whole house, they are considered the best and most comprehensive solution for homes.
In addition to portable and standby generators, inverter generators also provide a safe, clean power source when needed for sensitive electronics. However, they are typically used for outdoor and camping activities, not as a whole-home power source. Because the focus of this article is choosing the right size generator for your home, the remaining sections will primarily refer to a standby or whole-home generator, as it is the most reliable option for powering the entire house.
Common Whole-Home Generator Sizes and What They Power
Generators are categorized by their size, which relates to their electrical output (measured in kilowatts). The size of the generator a home will require depends on factors such as the number and type of appliances, the size of the house, and the amount of power the home uses. Below are the most popular sizes for residential use:
10-14 kW: These generators are suitable only for essential circuits. For example, lights, a refrigerator, a freezer, a sump pump, or a few outlets. These generators are best suited for smaller homes and budget-conscious homeowners who want the most basic coverage in a power outage. The power they provide is more of a partial backup than full coverage.
16-22 kW: With the addition of more kilowatts, this generator can power the essential circuits of an average-sized home, along with central A/C units, electric water heaters, electric ranges, and multiple appliances at one time. An ideal size for full-home support, generators in this size range can keep a medium-sized home fully operational in the event of a power disruption.
24-36 kW: The best size for larger homes with higher electrical demands, these generators can power multiple A/C units, pool heaters, and hot tubs.
38-60 kW: These commercial-grade units are suitable for residential properties such as large estates or home-based businesses. Units this large are not needed for the average Northborough home.
You can see there is a wide range of sizes for homeowners to choose from when picking a home backup system. Read below and learn how to calculate the right size for your home.
How to Calculate the Right Size Generator for Your Home
When choosing the right size generator for your home, you should never just guess. Undersizing a backup generator can leave you in the dark when you least expect it. Here’s a simple step-by-step guide to sizing a generator for your home:
- Identify and list every appliance you want to run during a power outage. Be sure to list items by their priority, starting with the “must-haves” and ending with the “nice-to-haves.”
- Find the running and starting wattage for each item on your list. The running wattage is the amount of power an appliance needs to stay running, while the starting wattage is the power required to start the appliance.
- Add up the running and starting watts of everything you wish to power during an outage. A generator must be large enough to handle both the starting and running wattage. For example, a refrigerator may need 700 watts to run, but over 1200 watts to start.
- Add the highest starting wattage to your total running watts. Convert wattage to kilowatts by dividing your number by 1,000, then add a 20% buffer to ensure your generator won’t have to run at 100% when in use (this will increase the lifespan of your generator and improve fuel efficiency).
While there are many online resources, such as calculators and DIY methods for generator size and installation, a professional electrician can ensure a generator is the right size, safe to operate, and dependable. Having an assessment for a generator installation in Northborough by a licensed electrician ensures that all factors are taken into account and that the proper size for your home is recommended.
The Right Fit for Your Home
Choosing the right home generator is an important decision for homeowners who don’t want to be left in the dark when the power grid fails. More complex than picking the largest size you can afford, choosing a home generator involves matching capacity to your needs. Understanding the different types and sizes available, and how to calculate your home’s unique electrical demands, can help keep your home powered when you need it most. While homeowners can estimate their power requirements, the safest and most accurate approach is to work with a professional. Interested in a whole-home generator? Consult with a reputable local electrical contractor to ensure your investment is safe and performs when you need it, providing comfort when the next storm rolls in.