Quick Answer: For a typical full-home, you'll likely need a generator between 15,000 and 30,000 watts. The exact wattage depends on the size of the home and the number of appliances. A 15,000-watt generator can cover the basics 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 so on. Carefully calculate your home's total wattage and size the generator at least twice as large for a safe and reliable backup supply.

Introduction

A home generator allows homeowners to maintain a normal standard of living even during extended power outages. Choosing the right generator size is crucial to ensure the proper functioning of all electrical systems and appliances during a blackout. The generator must be powerful enough to cover the full power required by the home, also taking into account the size 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 the generator you need?

To choose the ideal generator size for your home, several factors must be considered:
Number of appliances to be powered: If you want to power basic appliances like lighting, a refrigerator, and Wi-Fi, a small generator may be sufficient. However, if you want to power larger appliances like air conditioners, electric stoves, or washing machines, you'll need more power.
Starting Wattage vs. Running Wattage: When a refrigerator or air conditioner starts up, it requires additional power, called starting wattage, beyond the appliance's normal operating wattage. Also, consider both starting and running wattage to avoid overloading the generator.
The size of your home: Larger homes have more appliances and heating or cooling areas, requiring a more powerful generator to meet the increased demand.
The type of heating and cooling system: Air conditioners, electric radiators, and heat pumps consume a lot of electricity. Since these systems are the largest consumers of electricity in your home, you should take them into account 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 power to meet only essential needs during 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 using less fuel.

How to calculate your home's energy requirements?

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

Common electrical consumption of household appliances:

What size generator do you need for different home sizes?

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

Less than 180 m²: A 10,000- to 15,000-watt generator can power essential appliances such as lighting, refrigerators, freezers, boilers, and medical equipment. This type of installation is particularly suitable for cabins and small homes.

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

3,000 to 4,600 square feet: For larger homes, choose a 22,000- to 32,000-watt generator. This range can power electric furnaces, water heaters, multiple HVAC systems, and other large appliances.

Over 5,000 square feet: Homes larger than 5,000 square feet often require 36,000 watts or more, especially if they have equipment such as a pool, hot tub, or an electric vehicle charging station. Larger custom homes may require more than 50,000 watts.

The larger your home, the greater your electricity consumption. Carefully match the generator's power to the size of your home and your systems for optimal coverage during 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 lack the power needed to power an entire home. The output power of most standard portable solar generators ranges from 100 to 3,000 watts. This power can power smaller appliances such as phones, laptops, and lighting. However, it is insufficient to power energy-intensive appliances such as air conditioners, water heaters, and electric heaters.

A normal-sized home, especially in extreme climates, requires heating in the winter and air conditioning in the summer. These systems consume more than 3,000 watts. Therefore, standard portable solar generators struggle to meet the electrical needs of an entire home.

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

Whole-house generators are essential for households that require continuous power for their essential, high-power appliances during frequent and extended outages. Portable solar generators, on the other hand, are suitable for lighter needs, such as recharging small appliances and powering lighting during occasional, brief power outages.

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

Conclusion

A reliable backup power source gives you peace of mind when severe storms knock out the power. An accurate calculation of your home's total power needs and generator sizing guidelines will allow you to choose a system capable of powering essential, everyday appliances. Although whole-house units require a larger investment, their automatic operation and complete home coverage offer true energy security. With a generator matched to your electrical loads and living space, your home will remain powered even during an extended outage.