When it comes to preparing for power outages, one of the most reliable solutions is having a home generator. A generator can provide the necessary backup power to keep your home running during times of need. However, selecting the right size generator for your home can be a complex decision. Choosing the wrong size can lead to inefficiency, unnecessary costs, or even a system that doesn’t meet your needs. In this article, we will discuss how to determine what size generator is ideal for your home, based on your power requirements and other important factors.
Understanding Generator Sizes
Generators come in various sizes, and the size you need depends on the power demands of your home. The power of a generator is typically measured in watts, which is an indicator of how much electricity the generator can supply. The size of a generator you need will depend on the number of appliances and devices you wish to power simultaneously during an outage.
There are two primary types of generators for home use: portable generators and standby generators. Portable generators are smaller and can power only a few essential appliances, whereas standby generators are larger and can power an entire home, including heating systems, lights, and large appliances.
Portable Generators
Portable generators are ideal for homes that don’t require a full backup power system. These generators can supply enough energy to keep lights, refrigerators, and a few other essential appliances running. Portable generators are typically used in emergencies or for short-term power outages. They range from small units, offering about 1,000 watts of power, to larger ones capable of generating up to 10,000 watts.
Standby Generators
Standby generators are a permanent fixture installed outside your home. They automatically start working as soon as a power outage occurs. These generators are more powerful and can run your entire home without interruption. Standby generators can produce anywhere between 7,500 to 20,000 watts or more, depending on the size you choose. They are connected directly to your electrical panel and use either natural gas, liquid propane, or diesel fuel.
Factors to Consider When Choosing a Generator Size
When choosing a generator for your home, there are several factors to consider that will help determine the correct size.
1. Calculate Your Power Requirements
The most critical step in determining the right size generator is understanding how much power your home uses. You need to calculate the wattage required to run essential appliances such as your refrigerator, heating system, lights, and electronics.
To do this:
- Make a list of all the appliances you want to power during an outage.
- Check the wattage requirements for each appliance. Most appliances have labels that indicate how many watts they use.
- Add up the wattage for all the appliances you plan to run simultaneously.
- Don’t forget to account for startup watts, which are higher than running watts for some appliances like refrigerators and air conditioners.
2. Consider Your Future Needs
When selecting a generator, think not only about your current power needs but also about potential future requirements. If you plan to add new appliances or expand your home in the future, you may need a generator that can handle the increased load.
3. Generator Wattage
Generators are rated for their output in watts. There are two types of wattage to consider: running watts (the continuous power required to keep appliances running) and surge watts (the extra power needed when appliances start up).
Make sure that the generator you choose can provide enough running watts to support your household needs, plus a bit extra to cover surge watts. A general rule of thumb is to select a generator that can provide at least 20% more watts than the total running watts required for your appliances.
4. Fuel Type
The type of fuel your generator uses will also play a role in determining its size. Standby generators typically run on natural gas or propane, while portable generators can run on gasoline or diesel. The availability of these fuels in your area and the cost of running the generator will affect your choice.
5. Budget
Generators come in a wide range of prices, with portable generators generally being more affordable than standby units. While the initial investment for a standby generator is higher, they offer the convenience of automatic power restoration and can power your entire home. Portable generators, on the other hand, are cheaper but have limited capacity and require manual operation.
How to Size Your Generator
To properly size a generator, you need to take into account both the wattage of the devices you plan to power and how often you need to run them.
Here’s how you can do that:
Step 1: Identify Essential Appliances
Identify the appliances and systems that you absolutely need to power in an emergency.
These typically include:
- Refrigerator
- Heating and cooling systems (air conditioners, heaters, fans)
- Lighting
- Medical devices
- Well pump (if applicable)
- Home security systems
Step 2: Calculate Total Wattage
Next, calculate the total wattage required to power these appliances. For instance, a refrigerator may use 600 watts while starting up, but only 200 watts while running. An air conditioner might use 2,000 watts to start and 1,000 watts to run. Add up the running watts and surge watts for each appliance to get a total figure.
Step 3: Add a Buffer
Once you have the total wattage for your appliances, add about 20% to this number. This buffer will ensure that your generator can handle short-term surges and operate efficiently without being overloaded.
Step 4: Choose the Generator
Now that you have an accurate wattage estimate, you can choose a generator. For a small home, a generator that produces 5,000-7,500 watts may suffice. Larger homes or homes with more electrical demands may need a generator producing 10,000-20,000 watts.
Types of Generators
Generators can be categorized based on their type, fuel, and power capacity.
1. Inverter Generators
Inverter generators are a more advanced type of portable generator. They offer cleaner and more stable power, making them ideal for sensitive electronics like computers and televisions. Inverter generators are typically quieter and more fuel-efficient than conventional generators.
2. Diesel Generators
Diesel generators are more fuel-efficient and tend to have a longer lifespan compared to gasoline-powered generators. However, they can be louder and more expensive. Diesel is also a less common fuel source, and availability may vary depending on your location.
3. Natural Gas Generators
Natural gas generators are ideal for standby applications, as they can be connected directly to your home’s natural gas line. They are relatively low-maintenance and provide an uninterrupted power supply as long as the gas line remains functional.
4. Gasoline Generators
Gasoline generators are the most common and generally the most affordable type of portable generator. They are suitable for short-term use and are often chosen for emergency preparedness. However, gasoline has a limited shelf life, which can be an issue during long-term storage.
Generator Sizing Example
To better understand the process, let’s consider a typical home with the following power requirements:
-
Refrigerator: 600 watts
-
1-2 Window air conditioners: 2,000 watts each
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Lights: 300 watts
-
Microwave: 1,200 watts
-
Well pump: 1,500 watts
Total running watts = 600 + 300 + 1,200 + 1,500 = 3,600 watts
Total surge watts = 2,000 (air conditioners start-up) + 1,500 (well pump start-up) = 3,500 watts
Add a 20% buffer to this:
3,600 watts × 1.2 = 4,320 watts
In this case, a generator rated for at least 5,000 watts would be ideal, with the ability to handle both the running watts and the surge watts.
Conclusion
Choosing the right size home generator is a vital decision that ensures your home is protected during power outages. By understanding your power needs, accounting for surge watts, and considering factors like fuel type and budget, you can select a generator that will efficiently meet your household requirements. Whether you opt for a portable generator or a larger standby generator, the key is to accurately estimate your energy demands and choose a generator that offers enough power with a little extra capacity for peace of mind.
