Get matched with top generator install pros in Paradise, MI

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.

As a safety measure, you should always turn off the main breaker while operating your generator’s backup breaker. In addition, you should also switch off all appliance breakers so you don't have a power surge when the main breaker turns back on. And finally, turning off the main breaker prevents back-feeding, which endangers utility workers with the risk of electrocution. Back-feeding could also destroy the electrical circuits of your neighbors if they use the same power network.

You can expect a diesel generator to last for up to 30,000 hours of use, which works out to 20 to 25 years with the proper maintenance, of course. That depends on how much you use it, so a diesel generator used for emergencies a couple of times a year will last a lot longer than a generator that takes over for a faulty electrical grid every month for a day or two. 

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

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

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

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.