The average cost to install a Generac home generator, and the price jump between 18 kilowatts and 20-22 kilowatts, often surprises people. That extra couple of kilowatts doesn’t seem significant on paper.
However, the reality is that they’re completely different beasts. While smaller generators are designed to keep the basics running, like a fridge, some lights, or a sump pump, bigger generators (starting at 20 Kw) are a whole new league. These larger systems are built to power your entire house, not just a handful of appliances.
This is where the cost difference truly comes into play. It’s not just a bigger motor, but a shift in the entire system, from design and parts to what the unit can truly handle. Whole-house models cost more because they promise more, with smarter features, tougher construction, and sustained performance during longer outages.
Ultimately, you’re paying for that peace of mind — knowing your whole house will stay powered. When planning your backup system, remember that this jump means more than just a slightly bigger price tag. It signifies a different level of protection.
Decide what coverage fits your family and budget before making a final decision.
“So, how much should you expect to pay?,” asks an article on Home Maintenance HQ. “Well, home generators can range from $3,000 to $10,000 for the unit alone. But if you’re looking at a whole-home system, including installation, you’re probably looking at a range from $5,000 to $25,000. On average, most people spend around $5,090. This cost can go up or down depending on the factors we just talked about.”
Engine Technology and Average Cost to Install a Generac Home Generator
The engine plays a significant role in the average cost to install a Generac home generator, driving up the price. Smaller generators from 7.5 to 18 Kw typically use basic, budget-friendly air-cooled engines that are well-suited for short bursts and mild weather.
However, once you move above 20 Kw, changes in engine design become apparent. While some larger models still rely on air-cooling, their engines are generally bigger and include extra features for improved power and fuel efficiency.
For higher capacities, liquid cooling becomes the standard. This system cools the engine with a radiator and fluids, similar to a car’s engine. Liquid-cooled engines manage heat much better, which allows them to last longer, even during extended outages or in tough climates.
The increased cost of these liquid-cooled engines is due to the greater number of materials and parts needed for their construction, which is ultimately reflected in the final price of the unit.In the following table, note that cost ranges are averages and can vary significantly based on brand, location, specific installation complexities, and market conditions:
| kW Range | Typical Home Size/Coverage | Average Unit Cost Range | Average Installation Cost Range | Average Total Installed Cost Range |
| 1–6kW | Refrigerator, freezer, sump pump, lighting, small appliances | $500–$1,800 | $1,500–$5,000 | $2,000–$6,800 |
| 7.5–10kW | All essential appliances + well pump, furnace fan, lighting | $2,000–$3,500 | $1,500–$5,000 | $3,500–$8,500 |
| 14–18kW | Essential appliances + AC, hot water heater, additional appliances | $4,000–$5,500 | $1,500–$5,000 | $5,500–$10,500 |
| 20–24kW | All essential & non-essential appliances, multiple ACs, electric ranges | $5,000–$6,500 | $5,000–$12,000+ | $10,000–$18,500+ |
| 26–32kW | All home appliances & systems, larger HVAC, multiple hot water heaters | $6,500–$15,000 | $5,000–$12,000+ | $11,500–$27,000+ |
| 36–38kW | Large homes, extensive power needs | $14,000–$16,000 | $5,000–$12,000+ | $19,000–$28,000+ |
The Complete Picture on Installation and Extras
Researching the average cost to install a Generac home generator involves much more than simply picking out the machine. A small one, ranging from 7.5 to 10 Kw, typically costs between $2,000 and $3,500, while larger options designed to power an entire house often start at $5,000.
Yet, the machine’s price is just the beginning. Installation can often cost just as much, if not more. This is because electricians and plumbers must handle the setup to ensure it’s safe.
You’ll also need to budget for an Automatic Transfer Switch to manage the switch-over during power outages, as well as the cost of pouring a concrete pad to prep the site. Local permits also bring extra fees, and these steps can quickly add up, especially for bigger units, which is why the total cost can be surprising.
“Whole home generators capable of producing up to 20 kilowatts can cost between $10,000 and $15,000, including installation and hooking them up to gas lines,” according to Chelmervalve. “Homes with many large electrical appliances, central air conditioning, and electric heat will require a larger generator than homes with fewer appliances and electrical needs, typically in the range of 17kW to 20kW.”
Average Cost to Install a Generac Home Generator and Infrastructure
To figure out the average cost to install a Generac home generator, know that bigger generators come with extra expenses that often surprise people, particularly when it comes to fuel.
While hooking up a smaller unit is relatively simple because most homes can use their current gas line, larger systems, especially those over 20 Kw, require much more fuel. This could necessitate upgrading your gas line or swapping your meter for a stronger one, which your utility company typically handles at a significant cost.
Similarly, those who choose propane or diesel must purchase and install a large tank, adding another expense to the bill. These upgrades, while not reflected in the generator’s price tag, are a major reason why going big gets expensive quickly, and many people overlook these hidden costs until the bill arrives.
The higher cost of bigger generators is justified by their advanced technology. They are packed with smart tech that intelligently directs power where it’s needed most. Larger generator can handle running two air conditioner units simultaneously in the summer by ensuring one cools you off before the second kicks in, preventing overloads or blackouts. The power remains steady even with multiple appliances running.
Additionally, these machines produce clean electricity, which is crucial for protecting sensitive electronics like laptops or modern HVAC systems from damage. A bigger generator is more than just a metal box. It’s a reliable, silent helper that keeps your home running smoothly when the grid goes down.
Comfort, Convenience, and Reliability Over the Long Term
Generators with liquid cooling tend to last much longer, something that homeowners can overlook when calculating the average cost to install a Generac home generator. Certain brands thought that their engines can run for decades if properly maintained.
This longer lifespan contributes to the higher cost, as the price reflects the value and durability you receive.
Larger engines can also run more quietly because they aren’t strained. It’s not unusual for quieter models to hover around 60-65 dBA, which is less noise than some regular units. Additionally, strong, weatherproof covers help these machines endure storms or heatwaves, extending their usable years and offering owners peace of mind.
People who choose the larger models often feel a sense of relief and satisfaction. During power outages, their home life barely skips a beat, and they are impressed by the automatic start-up and the ability to power everything at once. Many homeowners who followed their electrician’s advice to get a slightly bigger generator later feel glad they made that choice.
“I realize I could’ve done this for less, but having it all taken care of – from A to Z – is worth it,” states one consumer on Reddit. “It promises to get into the hundreds a lot this summer and I’m not taking any chances.”
Electricians often recommend spending a little more upfront for a larger generator, such as a 22 Kw unit, because the installation cost is often the same as for an 18 Kw model. They view it as a wise investment that prepares you for any future needs, like adding a new oven or upgrading your laundry room.
Choosing the larger option now prevents the headache of running out of power later and keeps things running smoothly for years to come.
Market Trends and the Average Cost to Install a Generac Home Generator
People want home standby generators – and want to know the average cost to install a Generac home generator – for several reasons. With more frequent and intense storms and aging electrical grids, power outages are no longer a rare occurrence, making backup power feel necessary.
Our increasing reliance on technology to run everything in our homes, from laptops and medical equipment to smart refrigerators, means power cuts can disrupt life very quickly. This drives a need for steady, reliable power.
There is also a growing push for a sense of security and peace of mind, as parents want their children to feel safe if the lights go out. This combination of factors is fueling the expanding backup generator market, with machines becoming larger and stronger to meet climbing demand for safety and reliability.
W. Danley Electrical
What’s the average cost to install a Generac home generator? At W. Danley Electrical, we stand out in the world of home backup generator solutions. We assist you throughout the entire process.
We help prepare you for your installation, as well as obtaining permits, inspections, and assisting with repair and maintenance. We also help you optimize and fine-tune your situation to determine the correct generator size. We execute the backup standby generator process from beginning to end.
Additionally, we prepare you for your installation, as well as obtaining permits, inspections, and assisting with repair and maintenance. Get the most out of your investment. Contact us today.
