Sizing a generator is a careful process that requires calculating the electrical load of your entire house. You have to take into account every device you want to use and their wattage requirements, plus the wattage needed to start them, and look for a generator that can safely run all that at around 80% capacity.
In more practical terms, a small home can run on a 10,000-watt generator (and if you only want to power a few key appliances, much less than that). A mid-sized home may need something between 15,000 and 22,000 watts. Larger homes require 25,000 watts or more.
While standby generators provide essential backup power, they can fail when you need them most due to lack of maintenance, fuel supply issues, dead batteries, electrical problems, or improper installation. To avoid costly failures, professional installation and regular maintenance are crucial. Licensed technicians ensure safety, uphold warranty requirements, comply with regulations, and provide expert servicing.
Generators run on a variety of fuel types, ranging from natural gas to solar power. Keep in mind that fuel costs varying by type:
Natural gas: $2,000–$21,000 per year
Liquid propane: $2,000–$21,000 per year
Diesel: $3,000–$20,000 per year
Gasoline: $500–$3,000 per year
Solar generator: $2,000–$25,000 per unit
Battery backup: $10,000–$25,000 per unit
Generally, you’ll want to keep between 60 and 70 feet between the generator and the transfer switch. There are a few reasons for this, including:
The distance reduces the noise coming from the generator into your home.
It increases efficiency because you won’t have a voltage drop from this short of a distance.
Prevents carbon monoxide poisoning: keep at least 15 feet between your generator and an open window.
The average cost to install a home generator is $5,200, but total costs can range from $500 to $18,000 or more. The final price depends on several factors, including the generator's size, type, brand, fuel source, and the cost of labor and assembly. The generator's size is the most significant cost factor, as units that can power larger homes with higher energy demands cost more.
Cost breakdowns by generator type are typically as follows:
Portable or Emergency Backup Generators (1kW–7.5kW): $500–$2,000
To ensure you get the right size unit for your needs without overpaying, consider hiring an electrician to calculate the electrical load of your essential appliances. It is also recommended to get at least three quotes from qualified installers to find the best fit for your budget.
The Karlstad, MN homeowners’ guide to generator installs
From average costs to expert advice, get all the answers you need to get your job done.
Natural gas generators are whole-home standby generators that are connected to your home’s natural gas line. The average cost for a natural gas generator is $12,000.
Generators should give you peace of mind, but you’ll only get that if your installer knows what they’re doing. Learn how to hire a pro and what red flags to look for.