When the power goes out, whether due to a storm, an equipment failure, or a natural disaster, a generator can provide crucial backup power to keep your home running smoothly. However, choosing the right generator size is essential to ensure it meets your needs without being an over- or under-investment. This article will guide you through the process of understanding your power requirements, calculating your wattage needs, and selecting the best generator for your home.
Understanding Power Needs
Before purchasing a generator, it’s important to assess which appliances and systems in your home you need to keep running. Calculating the total wattage required ensures you choose a generator with sufficient power without excessive capacity.
Common Household Items and Their Average Wattage Requirements
The wattage needed for each appliance can vary, but here are some common items and their average wattage:
Refrigerator: 600-800 watts (starting surge may be higher)
Sump Pump: 800-1,200 watts
Window Air Conditioner: 1,200-1,800 watts
Microwave Oven: 1,000-1,500 watts
Electric Stove: 2,000-3,000 watts
LED Light Bulbs: 10-15 watts each
TV: 150-400 watts (depending on size)
Washing Machine: 500-1,000 watts
Hair Dryer: 1,000-1,800 watts
Space Heater: 1,500 watts
By totaling the wattages of the items you need to power, you can better understand your total energy requirements.
Types of Generators
Standby Generators
Standby generators are permanently installed outside the home and are automatically activated during a power outage. They connect directly to your home’s electrical system and can power the entire house.
Pros
Convenience: Automatic start-up when power is lost.
Capacity: Can support larger loads, including central HVAC systems and high-power appliances.
Longer Runtime: Runs on natural gas or propane, so they can operate for extended periods without refueling.
Cons
Cost: Initial purchase and installation are more expensive than portable generators.
Space: Requires a dedicated installation location.
Portable Generators
Portable generators are smaller, mobile units that can be moved and used to power selected devices during an outage.
Pros
Affordable: Typically less expensive than standby generators.
Versatile: Can be used for other outdoor activities like camping or tailgating.
No installation required: Can be used immediately once set up.
Cons
Limited Power: May not power an entire house, especially large appliances.
Manual Operation: Must be turned on manually when the power goes out.
Fueling: Requires gasoline or propane, and refueling may be necessary during extended outages.
Recommended Brands and Models
Standby Generators: Brands like Generac, Kohler, and Cummins are top choices for reliability and performance. The Generac Guardian Series and Kohler 20RESCL are popular for residential use.
Portable Generators: Brands like Honda, Westinghouse, and Champion are highly recommended for their efficiency and durability. The Honda EU2200i and Champion 100165 are widely used for backup power in small to mid-sized homes.
Calculating Total Wattage
To determine how much power your generator needs to supply, you must calculate both running watts (the continuous power required) and starting watts (the surge power needed to start certain appliances like refrigerators and air conditioners).
Step-by-Step Guide
List All Essential Appliances: Write down all the appliances and devices you want to power during an outage.
Find Their Wattage: Look for the power rating (in watts) on the appliance or consult the user manual.
Calculate Running Watts: Add up the running wattage for all devices you want to keep running.
Calculate Starting Watts: Some devices, like refrigerators, have higher startup wattage requirements. Ensure you add the highest surge wattage for those appliances.
Total Wattage: Add the total running watts and the highest starting watts to determine the generator size.
Example
- Refrigerator: 800 watts (running), 1,200 watts (starting)
- Microwave: 1,200 watts (running)
- Lights (10 bulbs): 150 watts
- TV: 400 watts
Total running watts = 800 + 1,200 + 150 + 400 = 2,550 watts
Total starting watts = 1,200 (refrigerator) + 2,000 (microwave) = 3,200 watts
Your generator should have at least 3,200 watts of starting capacity, and 2,550 watts of continuous capacity.
Generators and Wattage Calculators
There are various online calculators available that can simplify the process, such as the Generac Wattage Calculator or Kohler’s Generator Sizing Tool.
Considerations for Larger Homes
For larger homes or homes with specific power needs—such as home offices, medical equipment, or dedicated workshops—it’s crucial to either opt for a larger single unit or use multiple smaller generators. A larger generator may be able to handle the additional load, while multiple smaller units provide flexibility and reduce the risk of overloading a single generator.
Installation Requirements
Standby Generators
Installing a standby generator typically requires professional services. An electrician or certified installer will connect the generator to your home’s electrical panel and may need to apply for local permits, especially for gas-powered units. The process can take a few days to a week depending on the complexity.
Installation Tips
Ensure the generator is placed at least 5 feet away from windows, doors, and vents to avoid carbon monoxide buildup.
A transfer switch will likely be required to safely switch between grid and generator power.
Portable Generators
Portable generators are easier to set up but require proper safety precautions:
Keep them outdoors, far from windows and doors to prevent carbon monoxide poisoning.
Use a heavy-duty extension cord rated for outdoor use.
Never connect a portable generator directly to your home’s electrical system without a transfer switch.
Cost Factors
The cost of a generator depends on size, brand, and installation requirements.
Portable Generators: Typically range from $400 to $2,000, depending on size and brand.
Standby Generators: Can cost anywhere from $3,000 to $10,000, including installation.
Maintenance costs should also be considered. Standby generators often require annual servicing, while portable generators might only need occasional oil changes and upkeep.
Budgeting Tips
Consider the total cost of ownership, including installation and maintenance.
Some financing options, including loans and payment plans, may be available for larger generator purchases.
Real-World Examples
Case Study: The Thompson Family
The Thompson family, who live in a 2,500 sq. ft. home, decided to install a Generac 22kW standby generator after multiple extended power outages. They wanted to power their HVAC system, lights, and appliances during outages. After consulting an installer and calculating their total wattage, they chose the 22kW unit to cover all their needs comfortably. “We wanted peace of mind during the hurricane season, and this generator has performed flawlessly,” said Sarah Thompson.
Case Study: The Jones Family
The Jones family, with only two members, opted for a portable Honda EU2200i generator. They only needed to power a refrigerator, lights, and a few devices during short outages. At a cost of about $1,000, they found it to be a cost-effective solution.
Conclusion
Choosing the right-sized generator for your home involves understanding your energy needs, calculating the total wattage, and deciding between a portable or standby model. By considering the types of appliances you need to power, generator size guidelines, installation requirements, and cost factors, you can ensure that your home is prepared for power outages—keeping your family safe and comfortable no matter what.
