Get matched with top generator install pros in Quincy, MA

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.

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.

An undersized whole-house generator has the potential to overheat and shut down when you try to run a central AC system. This scenario can not only damage the whole-house generator, but can also trip your home’s breakers or cause electrical damage. To avoid this situation, hire a local generator installer to correctly size your whole-house generator.