Quick answer: For a typical whole house, you'll likely need a 15,000- to 30,000-watt generator. The exact wattage depends on the square footage of the home and the number of appliances. A 15,000-watt generator can cover most of a 2,000-square-foot home. Opt for a 22,000- to 30,000-watt generator for a home larger than 3,000 square feet to power air conditioners, heaters, well pumps, and more. Carefully calculate your home's total wattage and size the generator at least twice as large for safe, reliable backup power.

Introduction

A home generator allows homeowners to maintain a normal standard of living even during a prolonged power outage. Choosing the right size generator is crucial to ensure all electrical systems and appliances operate properly during a power outage. The generator must be powerful enough to cover the total power required by the home, while also taking into account the square footage and future energy needs. This article explains how to calculate your home's electrical needs and choose a generator powerful enough for full backup capacity.

What factors determine the size of generator you need?

When choosing the ideal generator size for your home, several factors should be considered:
The number of devices you need to power: If you want to power basic devices like lighting, a refrigerator, and Wi-Fi, a small generator may be sufficient. However, if you want to power larger devices like air conditioners, electric stoves, or washing machines, you'll need a larger generator.
Starting Power vs. Running Power: When a refrigerator or air conditioner starts, it requires additional power, called starting power, above the appliance's normal running power. Also, consider starting power and running power to avoid overloading the generator.
The size of your home: Larger homes have more appliances and heating or cooling zones, requiring a more powerful generator to meet the increased demand.
Heating and cooling system type: Air conditioners, electric heaters, and heat pumps consume a lot of electricity. Since these systems are the largest electricity consumers in your home, you should consider them when choosing a generator model.
Essential vs. Non-essential Loads: Separate essential appliances, such as a refrigerator or medical equipment, from non-essential appliances, such as a home theater or outdoor lighting. This way, you can adjust the generator's output to only meet essential needs in the event of a power outage.
Fuel Type and Generator Efficiency: Different fuel types (gasoline, propane, or diesel) and generator models have different efficiencies. Some generators can provide more power while consuming less fuel.

How to calculate your home's electricity needs?

The most important factor in choosing a home generator is calculating your home's power needs. Add up the power of all the electrical appliances you want to run in the event of a power outage. This includes lighting, refrigerators and freezers, boilers, security systems, well pumps, and other essential equipment. Typically , a generator twice as powerful as your total wattage needs will provide enough power. It's also a good idea to consider future power needs if you plan to purchase additional appliances. A professionally installed home generator will automatically and safely power appliances and systems in the event of a power outage.

Typical electrical consumption of household appliances:

What size generator do you need for different house sizes?

Once you've calculated your energy needs, you can determine the appropriate generator power. Most whole-house generator systems range from 10,000 to 60,000 watts. Here are some typical power guidelines based on the size of your home:

Less than 180 m²: A 180- to 15,000-watt generator can power essential appliances like lighting, refrigerators, freezers, boilers, and medical devices. This type of installation is particularly suitable for small cabins and cottages.

180 to 270 m²: Opt for a 15,000 to 22,000-watt generator for an average-sized home. This will allow you to run most appliances, air conditioners, sump pumps, and other common home systems.

270 to 460 m²: For larger homes, choose a generator between 22,000 and 32,000 watts. This range can power electric furnaces, water heaters, multiple HVAC systems, and other large appliances.

Over 5,000 square feet: Homes over 5,000 square feet often require 36,000 watts or more, especially if they have amenities like a pool, hot tub, or electric vehicle charging station. Larger custom homes may require over 50,000 watts.

The larger your home, the more electricity you'll use. Carefully match your generator's power to the size of your home and your systems for optimal coverage in the event of a power outage. A properly sized unit will automatically power your most important appliances.

Can a portable solar generator power an entire house?

Most portable solar generators don't have the power to power an entire house. The output power of most conventional portable solar generators ranges from 100 to 3,000 watts. This power is enough to power smaller appliances like phones, laptops, and lighting. However, it's not enough to power energy-hungry appliances like air conditioners, water heaters, and electric stoves.

A typical-sized home, especially in extreme climates, requires heating in the winter and air conditioning in the summer. These systems consume over 3,000 watts, making it difficult for conventional portable solar generators to meet the electrical needs of an entire house.

When to choose whole-house generators or portable solar generators?

Home generators are essential for homes that require continuous power for essential, high-power appliances during frequent and prolonged outages. Portable solar generators, on the other hand, are suitable for lighter needs, such as charging small appliances and powering lighting during occasional, brief power outages.

Installation requirements, budget, and environmental impact must also be considered. Home generators require a significant initial investment, significant installation space, and recurring maintenance costs, but they offer comprehensive backup power. Portable solar generators, on the other hand, are more economical and environmentally friendly, offering a flexible and easily scalable power solution without the need for professional installation.

Conclusion

Reliable backup power gives you peace of mind when severe storms knock out the power. Accurately calculating your home's total power needs and following generator sizing guidelines will help you choose a system capable of powering essential, everyday appliances. While whole-house units require a larger investment, their automatic operation and complete home coverage provide true energy security. With a generator that's tailored to your electrical loads and living space, your home will remain powered even during a prolonged outage.