Get matched with top generator install pros in Roosevelt, NY

A 1,500 square foot home will likely need a 15kW to 20kW generator. When deciding on whole-house generator size, add up the total wattage of the devices that you’d like to continue running during a power outage. That way, you can ensure you purchase a generator that can power your necessary appliances or medical equipment during an electrical emergency.

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. 

No, you should never plug a generator directly into a wall outlet in your house. This practice is extremely dangerous, often illegal, and can cause "back-feeding," where power from the generator flows back into utility lines, creating a life-threatening hazard for utility workers. It can also damage your home's electrical system, including appliances like pumps and HVAC fans. If the main power is restored while the generator is connected, it can destroy the generator and cause an electrical fire. To safely connect a generator, you must use a professionally installed transfer switch or an interlocking kit, which prevents back-feeding by disconnecting your home from the utility grid before the generator provides power.

The cost to install a whole-house generator averages $5,200, with a typical price range of $1,500 to $8,900. However, total costs can vary from $400 for a small portable unit to over $18,000 for a large-capacity system. The most significant cost factor is the generator's size and capacity, but other variables include the brand, fuel type, and labor for assembly and installation.

Generator costs can be broken down by type:

• Portable or Emergency Backup Generators (1kW–7.5kW): $500 to $2,000

• Partial-Home Generators (9kW–20kW): $2,000 to $6,500

• Whole-House Generators (22kW–48kW): $5,000 to $18,000

To avoid paying for more power than you need, consider hiring an electrician to calculate the electrical load for your essential appliances. It is also recommended to get at least three quotes to find the best deal for your specific needs and budget.