Get matched with top generator install pros in Honokaa, HI

You can determine what size generator you need for a transfer switch by matching the switch to the largest outlet on your generator. Larger generators can power up to 10 circuits, while most 5,000-watt generators can provide power to six circuits. So, if your generator’s largest outlet is 30 amps, you’ll need a 30-amp transfer switch.

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

You may need a permit for a portable generator if you’ll be installing a transfer switch for your primary residence or similar work. Otherwise, a permit for other uses may not be necessary. Check your local building codes or ask a local generator installer for more information about your local regulations.

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.