The short answer is: To choose the right generator size for your home, figure out what you need to power during an outage (essentials vs. everything), add up the total running and starting wattage of those items, and plan a little extra for future needs. A 25kW generator covers the basics; a 35kW handles most full-home setups. Bigger isn’t always better—match the generator to your actual usage to avoid waste and ensure reliability.
When the power goes out, the last thing you want is to be left without a reliable source of electricity. Whether it's for keeping essential appliances and medical devices running, protecting against food spoilage, or maintaining comfort during extreme weather conditions, having a whole-home generator can be a lifesaver.
But how do you choose the right generator size for your home? In this guide, we'll walk you through the process, helping you select a generator that fits your needs so that you’re prepared when the next power outage strikes.
Selecting the right-sized generator for your home isn’t just about purchasing the most powerful one available. Oversized generators can waste fuel and be unnecessarily expensive, while undersized generators might not be able to power all the appliances and systems you want to access during an outage.
The key is to find a generator that offers enough wattage to run everything you need during an outage, without overloading or wasting energy.
Before buying a generator, you need to determine your current and future power needs, and think about operating efficiency.
The first step is to determine your household’s power requirements. This involves identifying the appliances and systems you want to power during an outage. These might include:
Essential Appliances: Refrigerators, freezers, lighting, and heating/cooling systems.
Medical Equipment: Oxygen concentrators, CPAP machines, or other devices.
Electronics: Televisions, computers, and home office equipment.
Home Comfort and Protection: Sump pumps, water heaters, security systems, and other equipment.
Start by making a list of all the essential items you need powered during an outage. You should then calculate the wattage required to run these devices.
Generators are typically rated in watts and are available in two main types of power ratings: running watts and starting watts.
Running Watts: This is the continuous power the generator can provide while running. When choosing a generator, this is the most important number to consider, as it determines how much load the generator can sustain over time.
Starting Watts: Certain appliances, particularly those with motors (like refrigerators and air conditioners), require extra power to start. This is the surge power rating. For example, a refrigerator may use 600 watts while running, but it may require 1,200 watts to start. Always take this surge requirement into account.
Once you know which appliances you want to power, the next step is to add up the wattage required for each of them.
Step 1: Look at the wattage rating on the appliance or device's label (typically in watts or amperes).
Step 2: Add up the running watts for all appliances you want to power simultaneously.
Step 3: For devices with motors (like air conditioners or refrigerators), add the starting watts to the running watts to determine the total surge wattage.
Here’s an example calculation for powering what some would consider “essential” home appliances:
To run all of these, your Cincinnati home would need at least a 25kW generator.
Now if you’re looking to keep about everything on in your home, the list of appliances would look something more like this:
In this case, you’re looking more at a 35kW whole-home generator at minimum.
When selecting a generator, it’s a good idea to plan for future power needs. Consider potential additions to your home, such as a new appliance or even a home office setup, that might require more electricity later on. Selecting a generator with a little extra capacity now means you’ll be prepared for changes in your power needs over time.
Choosing a high-quality generator from a reputable brand is the best bet for long-term reliability. Look for customer reviews and ratings, and choose a brand that offers excellent customer service and warranty options.
At Thomas & Galbraith, we offer Generac generators to suit your needs and budgets. Our team can assist you with selecting and installing your generator so you can be confident it’s the right fit for your home.
Choosing the right size generator to run your entire home requires careful planning and consideration of your specific power needs. By understanding your wattage requirements, selecting the right type of generator, and planning for future power needs, you can make sure that your home is well-prepared for any power outage.
At Thomas & Galbraith, we’re here to help you make the right choice. Our expert team can guide you through every step of the process, from selection to installation, to provide you with a reliable backup power solution for your home.
Don’t wait for the next storm—make sure you’re ready with a generator that meets your needs and keeps your home powered when it matters most. For assistance with selecting or installing a whole-home generator, request a free estimate from Thomas & Galbraith today!