Get matched with top generator install pros in Litchfield, IL

In most municipalities, you will need a permit to install a permanent home generator, including emergency backup, partial-home, and whole-home generators. A permit for a generator usually costs between $50 and $250, depending on where you live. Your electrician or certified generator installer will usually pull the permit for you—and might be required to do so by your building department—but you’ll be on the hook for the cost of the permit. You should ask your installer before agreeing to any work if they will pull the necessary permits for your project.

To determine the right size generator for your house, you should calculate the total wattage of the appliances and devices you want to power during an outage. List all essential items, note their start-up wattages, and add them together.

Here are some typical wattage requirements for common appliances:

• Refrigerator: 600 watts

• Large dehumidifier: 700 watts

• Large window air conditioner: 1,400 watts

• Water heater: 3,000 to 4,500 watts

• Electric furnace: 5,000 to 25,000 watts

A 7,500-watt generator might be sufficient for essentials like a refrigerator, freezer, well pump, and lighting circuits. However, for high-demand items like a water heater or furnace, a whole-home generator is a better choice. A portable generator may be enough if you only need to power a few critical items.

While home square footage can offer a rough estimate, it is not always a reliable indicator. For reference, here are some typical generator sizes based on square footage:

• 1,000 sq ft: 6–9 kW

• 1,500 sq ft: 7–10 kW

• 2,000 sq ft: 10–14 kW

• 2,500 sq ft: 12–16 kW

• 3,000 sq ft: 16–20 kW+

For the most accurate sizing, consult a professional who can calculate your home's peak and average power consumption and recommend the optimal generator.

If you’re wondering if you can use your electric vehicle as a backup battery, it depends on whether your EV is compatible with bidirectional charging. This technology allows energy to flow both ways, enabling vehicle-to-home (V2H) backup power, vehicle-to-load (V2L) for appliances and camping, and vehicle-to-grid (V2G) to support the power grid. Compatible EVs convert stored DC energy into usable AC power, helping reduce energy costs and enhance grid stability while providing emergency backup power.

To power a central air system during a power outage, the whole-house generator will need to be at least 5,000 watts, and this number will significantly increase for larger units. Check the specific wattage requirements of your AC unit to choose the right generator size. Consider consulting a generator installer to ensure your whole-house generator meets your electrical load needs.