The power goes out. Your food starts spoiling. Your sump pump stops working. Your home office goes dark. Your family sits in the heat — or the cold — waiting for the grid to come back.
A backup generator prevents all of that.
But shopping for one feels overwhelming. Prices range from $300 to $25,000+. There are portable models, standby units, solar options, gas-powered, propane, diesel — and then there’s installation, permits, transfer switches, and maintenance on top of the purchase price.
This guide cuts through all of it. We’ll walk you through exactly how much a backup generator costs in 2026, what drives the price up or down, and how to pick the right one for your home or business — without overpaying.
How Much Does a Backup Generator Cost?
The short answer: $300 to $25,000+, depending on the type, size, and installation requirements.
Here’s the big picture at a glance:
| Setup Type | Total Cost (Unit + Installation) |
|---|---|
| Small portable generator | $300 – $1,500 |
| Mid-range portable generator | $1,500 – $4,000 |
| Small standby (7–10 kW) | $4,500 – $8,000 installed |
| Mid-size standby (13–20 kW) | $8,000 – $15,000 installed |
| Whole-home standby (22–25 kW) | $10,000 – $20,000 installed |
| Large home / commercial (30 kW+) | $15,000 – $25,000+ installed |
| Solar battery backup system | $3,500 – $15,000+ |
The national average for a whole-home standby generator installation is approximately $15,000 — for an 18kW unit in a 2,000 sq. ft. home, fully installed.
Most homeowners end up spending between $7,500 and $20,000 for a complete system.
Cost by Generator Type
Generator type is the biggest pricing variable. Each type serves a different use case — here’s exactly what you get at each level.
Portable Generators — $300 to $4,000
Portable generators are the most affordable option. You wheel them out, add fuel, pull the cord, and connect appliances manually via extension cords or a transfer switch.
They’re best for short outages and powering essential items — a refrigerator, a few lights, phone chargers. They don’t power your entire house and they require you to be home to operate them.
- Small portable (2–5 kW): $300 – $1,500 — runs basics during a short outage
- Larger portable (7–10 kW): $1,500 – $4,000 — powers more appliances including a refrigerator, sump pump, and microwave
Pros: Affordable upfront, portable, no installation required
Cons: Manual operation, noisy, needs refueling, can’t run unattended
Inverter Generators — $400 to $5,000
Inverter generators are a premium version of portable generators. They produce cleaner, more stable power — safe for sensitive electronics like laptops, TVs, and medical equipment. They’re also significantly quieter than standard portable models.
- Small inverter (1–3 kW): $400 – $1,200
- Larger inverter (3–7 kW): $1,200 – $5,000
Pros: Quiet, clean power, fuel-efficient, great for electronics
Cons: More expensive than standard portables, limited capacity
Standby Generators — $4,500 to $25,000+ (installed)
Standby generators are permanently installed outside your home — similar to an HVAC unit. They connect directly to your home’s electrical panel via an automatic transfer switch (ATS). The moment the power goes out, the generator detects it and turns on automatically — usually within 10–20 seconds.
You don’t have to do anything. It starts itself, powers your home, and shuts off when grid power returns.
- Small standby (7–10 kW): $4,500 – $8,000 installed — for small homes, essential circuits
- Mid-size standby (13–16 kW): $8,000 – $12,000 installed — partial home coverage
- Large standby (22–25 kW): $12,000 – $20,000 installed — whole home coverage
- Commercial standby (30 kW+): $15,000 – $25,000+ — large homes, businesses
Pros: Fully automatic, powers entire home, runs on natural gas (no refueling), unlimited runtime
Cons: Expensive upfront, requires professional installation, permits required
Solar Battery Backup Systems — $3,500 to $15,000+
Solar battery systems are the newest category — and the fastest-growing. Instead of burning fuel, they store electricity in large battery banks, charged by solar panels or the grid. When power goes out, they switch on silently and instantly with no emissions and no noise.
- Entry-level system (5–10 kWh): $3,500 – $7,000
- Mid-range system (15–20 kWh): $7,000 – $12,000
- Whole-home solar backup: $12,000 – $15,000+
Pros: No fuel cost, silent, zero emissions, qualifies for federal tax credits
Cons: Limited runtime (depends on battery size), slower recharging, high upfront cost
Cost by Generator Size
Generator size is measured in kilowatts (kW). The more kW, the more appliances you can run simultaneously. Here’s what each size range covers and what it costs:
| Generator Size | What It Powers | Unit Cost Only |
|---|---|---|
| 2–5 kW | Lights, phone/laptop charging, router, small fan | $300 – $1,500 |
| 7–10 kW | Fridge, sump pump, microwave, lights, essentials | $2,000 – $3,500 |
| 13–16 kW | Partial home: most appliances, A/C not included | $3,500 – $5,000 |
| 17–20 kW | Near-whole-home coverage, partial A/C | $4,000 – $6,200 |
| 22–25 kW | Full whole-home backup, HVAC included | $4,500 – $12,500 |
| 30–48 kW | Large homes, heavy loads, full commercial use | $10,000 – $25,000 |
How to estimate your size: Add up the wattage of every appliance you want to run simultaneously. Add 20% buffer. That’s your minimum kW requirement. For most average homes (2,000–3,000 sq. ft.), a 16–22 kW standby generator covers everything comfortably.
Cost by Fuel Type
Fuel type affects both the upfront unit cost and your long-term operating expenses. Here’s how each compares:
Natural Gas — $3,000 to $10,000+ (unit only)
The most popular choice for standby generators. Connects directly to your home’s existing natural gas utility line — no tanks to fill, no running out of fuel, essentially unlimited runtime during an outage.
Best for: Homes with existing natural gas service who want a permanent, hassle-free solution.
Propane — $3,000 to $10,000+ (unit only)
Works similarly to natural gas but requires an on-site propane tank. Tank installation adds $500 – $3,000. You’ll need to monitor and refill the tank periodically.
Best for: Homes in rural areas without natural gas service.
Diesel — $5,000 to $20,000+ (unit only)
Common in commercial applications. Diesel generators are durable and fuel-efficient but require on-site fuel storage and are louder than gas-powered options. Diesel fuel can also degrade after 12–18 months in storage.
Best for: Commercial facilities, data centers, industrial applications.
Gasoline — $300 to $4,000 (unit only)
Used almost exclusively in portable generators. Gasoline is widely available but has the shortest shelf life and requires the most frequent refueling during extended outages.
Best for: Portable backup for short-term outages and emergencies.
Solar / Battery — $3,500 to $15,000+
No fuel cost at all. The battery charges from solar panels or the grid and discharges during outages. Completely silent and emission-free.
Best for: Eco-conscious homeowners, those with existing solar panels, areas with frequent but short outages.
Installation Costs Breakdown
The generator unit is only part of the total cost. Installation is a significant — and often underestimated — expense. Here’s where installation money goes:
| Installation Component | Typical Cost |
|---|---|
| Labor (electrician + technician) | $1,500 – $5,000 |
| Automatic Transfer Switch (ATS) | $600 – $1,200 |
| Concrete pad or gravel base | $500 – $1,500 |
| Gas line extension / hookup | $500 – $2,000 |
| Trenching (underground lines) | $500 – $2,000 |
| Electrical panel upgrades | $1,000 – $3,000 |
| Permits and inspections | $200 – $800 |
Total installation cost range: $3,000 – $10,000 depending on complexity.
Simpler installations — where gas lines are already close, the panel is modern, and no trenching is required — land at the low end. Older homes requiring panel upgrades, long gas line runs, or complex wiring sit at the high end.
Hidden & Ongoing Costs
The purchase and installation price is just the beginning. Factor these ongoing costs into your total budget.
Annual Maintenance — $200 to $650/year
Like a car engine, a generator needs regular servicing — oil changes, spark plug replacement, air filter cleaning, battery checks, and load testing. Most manufacturers recommend annual professional service.
Fuel Costs — $25 to $200 per day of use
During an extended outage, fuel costs add up fast:
- A 20kW natural gas generator running at 50% load uses roughly $20–$40 worth of gas per day
- Diesel and propane costs are similar
- Gasoline for portables can run $15–$30/day depending on load
Transfer Switch Replacement — $600 to $1,200 (every 10–15 years)
Transfer switches have a long lifespan but do eventually need replacement.
Extended Warranty — $300 to $800
Standard warranties cover 2–5 years. Extended warranties to 10 years are available from most manufacturers and are worth considering for expensive standby units.
Fuel Storage (Propane/Diesel) — $500 to $3,000
If you use propane or diesel, you’ll need appropriate on-site storage tanks.
Best Backup Generator Brands
These are the most trusted and widely available brands in 2026:
| Brand | Best For | Reputation |
|---|---|---|
| Generac | Whole-home standby, widest selection | Most popular residential brand in the US |
| Kohler | Premium standby, ultra-quiet models | Known for quality and longevity |
| Briggs & Stratton | Mid-range standby and portable | Solid value, good dealer network |
| Honda | Portable and inverter generators | Best-in-class portable reliability |
| Champion | Budget-friendly portable and standby | Best value for first-time buyers |
| Cummins | Commercial and large residential | Industrial-grade reliability |
| Tesla Powerwall | Solar battery backup | Best home battery ecosystem |
Generac controls approximately 70% of the residential standby generator market — their parts, dealers, and technicians are widely available across the country.
How to Choose the Right Generator
Use this simple decision framework to find your ideal generator.
Step 1: Decide What You Need to Power
Make a list of every appliance and system you want running during an outage. Common essentials:
- Basic needs: Lights, refrigerator, phone charging, internet router
- Comfort: Central air conditioning, heating system
- Health: Medical equipment (CPAP, oxygen concentrators)
- Convenience: Sump pump, water heater, washer/dryer, home office
Add up the total wattage to determine the minimum kW you need.
Step 2: Decide How Hands-On You Want to Be
- Want automatic protection, no effort required? → Standby generator
- Okay with manual setup for short outages? → Portable generator
- Want eco-friendly and silent operation? → Solar battery backup
Step 3: Consider Your Fuel Access
- Have natural gas service? → Natural gas standby is the most convenient choice
- Rural, no gas line? → Propane standby or large diesel portable
- Have solar panels already? → Battery backup expansion is the smartest investment
Step 4: Set Your Budget
| Budget | Best Option |
|---|---|
| Under $2,000 | Quality portable generator (Honda EU2200i or Champion 3500W) |
| $2,000 – $5,000 | Large inverter portable or entry-level solar battery |
| $5,000 – $10,000 | Small standby (7–13 kW) with installation |
| $10,000 – $20,000 | Mid to large standby (16–25 kW), fully installed |
| $20,000+ | Large whole-home standby or premium solar backup system |
Ways to Save Money
Backup generators are a major investment. Here’s how to get the most for your money.
- Get multiple quotes — installation labor costs vary dramatically between contractors. Get at least three quotes before committing
- Buy at the end of hurricane season — October and November see discounts as demand drops after peak storm season
- Look for manufacturer rebates — Generac, Kohler, and Briggs & Stratton regularly offer seasonal promotions and rebates
- Check utility rebates — some electric utilities offer rebates for installing backup power systems, particularly battery-based ones
- Claim the federal tax credit — solar battery systems that charge from solar panels qualify for the 30% federal Investment Tax Credit (ITC), which can save thousands
- Don’t overbuy capacity — a 22kW generator that covers your actual needs beats a 30kW unit that’s twice the price for capacity you’ll never use
- Bundle the transfer switch — buying the generator and ATS from the same vendor and having them installed together is almost always cheaper than doing them separately
- Consider a home warranty plan — some home warranty companies include generator coverage, which offsets annual maintenance costs
Frequently Asked Questions
How much does a whole-house backup generator cost in 2026?
A whole-home standby generator — unit plus professional installation — typically costs $10,000 to $20,000 for most homes. The national average sits around $15,000 for an 18kW system in a 2,000 sq. ft. home. Larger homes or more complex installations can reach $25,000.
What size generator do I need for a 2,000 sq. ft. home?
Most 2,000 sq. ft. homes with central air conditioning need a 16–22 kW standby generator for full whole-home coverage. If you only need essentials (no A/C), a 10–13 kW unit is usually sufficient.
How long does a backup generator last?
A quality standby generator with regular maintenance lasts 20–30 years. Portable generators typically last 10–15 years with proper care. The engine is the most critical component — follow the manufacturer’s oil change and service schedule religiously.
Do I need a permit to install a backup generator?
Almost always yes. Standby generator installation requires electrical and sometimes gas permits in virtually every municipality. A licensed electrician handles this — it’s built into the installation cost. Never skip permits — unpermitted generator work can void your homeowner’s insurance and create liability issues.
Is a standby generator worth the cost?
For most homeowners in areas with regular outages, yes — especially if you have medical equipment, a finished basement with a sump pump, or work from home. A single extended outage can cost thousands in spoiled food, hotel stays, and lost productivity. For areas with rare, short outages, a quality portable generator ($1,500–$3,000) delivers most of the value at a fraction of the price.
How much does it cost to run a generator per day?
Running a 20kW natural gas standby generator at 50% load costs roughly $30–$50 per day in fuel. Diesel and propane are similar. Gasoline portables cost slightly less per day but require more frequent refueling. Solar battery systems have zero fuel cost — but limited daily capacity.
What is an automatic transfer switch and why does it matter?
An automatic transfer switch (ATS) is the device that detects a power outage and switches your home’s electrical panel from grid power to generator power automatically. Without it, you’d have to manually connect appliances to the generator via extension cords. The ATS costs $600 – $1,200 and is non-negotiable for any standby generator installation.
Can a portable generator power my whole house?
Not typically. A portable generator powerful enough to run everything in a full-size home would need to be 15 kW+, which is unusual for portables and still requires a transfer switch for safe hookup. Most portable generators power selected essential circuits or individual appliances — not the full home. For whole-home coverage, a standby generator is the right tool.
A backup generator is one of those purchases you hope you never need urgently — but are enormously glad you have when you do. Take the time to size it correctly, hire a licensed installer, and maintain it annually. A well-maintained generator is a 20-year investment in peace of mind.