Gas generator cost is one of the biggest questions for homeowners planning backup power. Prices typically start at $500 for small portable models and can reach $15,000–$20,000 for whole-home standby systems.
At Grounded Electric, our licensed team – led by head electrician Robert “Bobby” Mulholland and project manager Barret Abramow – has guided families across Bergen County through price factors, installation steps, and ownership considerations.
This guide outlines what to expect, including variations depending on fuel type and vehicle size, and provides guidance on planning for both upfront and ongoing costs.
Key Takeaways
- Gas generator cost varies widely, with portable units starting near $500 and whole home standby generators reaching $15,000–$20,000 depending on size and features.
- Installation adds $3,000–$6,000 to the total cost, influenced by permits, gas line trenching, and electrical panel upgrades.
- Running costs differ by fuel type, with natural gas averaging $0.20–$0.35 per kWh, propane $0.35–$0.50, and gasoline often higher.
- Home size strongly impacts cost, as a 1,500 sq ft home may need a $7,000–$9,000 system, while larger 3,000+ sq ft homes often require $15,000–$20,000 setups.
- Long-term ownership costs include annual maintenance of $200–$500, with warranty coverage and fuel efficiency significantly affecting overall value.
Average Gas Generator Costs
Natural Gas Generator Cost
The cost of a natural gas generator depends on capacity, fuel efficiency, and brand. Homeowners may expect to pay between $2,500–$5,500 for smaller units, while large standby generators can exceed $10,000. Additional features, such as noise control or monitoring, also increase prices.
Natural Gas Home Generator Cost
Natural gas home generator cost increases with size. A modest unit to cover essentials may be $3,000–$6,500, while a full home standby generator often exceeds $12,000. For many families, this peace of mind outweighs higher pricing.
Portable Gas Generator Cost
Portable units are flexible and less costly, ranging from $500 to $2,000. They require manual setup and cannot match the seamless performance of installing a whole-home generator.
Generac Gas Generator Cost
Generac is one of the most recognized brands in house generators. Models range from $2,000 portables to $15,000 home standby generator systems. Many include an automatic transfer switch for convenience.
Home Depot Gas Generator Cost
Home Depot sells portable and stationary models across brands. Options start under $500 for small gasoline units and reach $10,000+ for standby systems. Warranty and delivery should be factored into the total cost.
Generator Cost for 1,500–2,000 sq ft House
For a 1,500–2,000 sq ft home, a complete system often costs $7,000–$12,000. These totals include the unit, installation, and an automatic transfer switch.
Generator Cost for Larger Homes (2,500–3,500 sq ft)
Larger homes require higher capacity systems. A 2,500 sq ft property may need a 20 kW generator costing $10,000–$14,000 installed. At 3,000–3,500 sq ft, costs reach $15,000–$20,000 depending on fuel and upgrades.
Approximate costs by size:
- 1,500 sq ft: $7,000–$9,000
- 2,000 sq ft: $9,000–$12,000
- 2,500 sq ft: $10,000–$14,000
- 3,000–3,500 sq ft: $15,000–$20,000
Installation and Operating Costs
Natural Gas Generator Installation Cost
Natural gas generator installation cost runs $3,000–$6,000. Key factors are permits, panel upgrades, trenching, and labor.
Gas Generator Cost per kWh
Gas generator cost per kWh averages $0.20–$0.35, depending on fuel and load. Running at partial capacity reduces efficiency.
Gasoline Generator Cost per kWh
Gasoline generator cost per kWh is higher, typically $0.35–$0.50. Units are cheaper upfront but more expensive long term.
Runtime on 1 Gallon of Gas
A gallon of gas usually powers a mid-sized portable generator for 3–5 hours at half load. Results vary by fuel type and model.
Runtime on 500 Gallons of Propane
A 500-gallon propane tank can last 7–10 days, as generators typically use 2–3 gallons per hour. This makes propane reliable for extended outages.
Running Cost by Fuel Type
Consumption rates and local prices determine the cost of running a generator. On average:
| Fuel Type | Consumption (per hour at 50% load) | Avg. Price | Cost per Hour | Cost per 24 Hours |
| Natural Gas | 0.75–1.5 therms | $1.20/therm | $0.90–$1.80 | $22–$43 |
| Propane | 2–3 gallons | $2.75/gallon | $5.50–$8.25 | $130–$200 |
| Gasoline | 0.75–1.25 gallons | $3.50/gallon | $2.60–$4.40 | $62–$105 |
Choosing the Right Generator
What Size Gas Generator Will Run a House?
A 7–10 kW unit covers essentials, while a 20–25 kW standby generator powers an entire home. Cost rises with capacity, so balance needs with budget.
Residential vs. Commercial Needs
Residential generators focus on home circuits, while commercial power generators supply larger facilities. Barrett Abramow often advises clients to list critical systems first to guide decisions.
Balancing Upfront and Lifetime Ownership Costs
Portable units cost less upfront but use more fuel and require more upkeep. Installing a whole home generator is pricier initially, but efficiency and reliability reduce expenses.
Key Factors That Influence Price
Size and Power Output
Larger homes need bigger house generators, which cost more to buy and install.
Fuel Type and Efficiency
The type of fuel used by generators shapes both installation costs and long-term expenses. Natural gas is affordable, gasoline is costly, and propane is reliable but requires tanks.
Comparing Natural Gas, Propane, and Gasoline
Natural gas is usually the lowest cost if a line is available. Propane is a reliable source during outages, but it is more expensive. Gasoline is widely accessible, but it is the most expensive option for long-term use. Homeowners comparing options may also consider the best diesel generator for durability.
- Natural Gas – Low-cost, steady supply.
- Propane – Long storage life, higher cost.
- Gasoline – Cheap units, but expensive to run.
Brand, Warranty, and Lifespan
Brands like Generac and Kohler cost more but provide strong warranties. A well-maintained system may last 15–20 years, resulting in lower annual costs.
Maintenance and Repair Costs
Annual inspections, oil changes, and small parts are common. Programs often run $200–$500 yearly. Robert “Bobby” Mulholland stresses proactive care to prevent breakdowns.
Understanding the Full Cost of Gas Generators
U.S. Department of Energy averages show natural gas at $0.20–$0.35 per kWh, propane at $0.35–$0.50, and gasoline often above $0.40. These figures confirm the ranges covered in this guide.
The total cost varies depending on home size, installation, and fuel source. Purchase, installation cost, and ongoing maintenance all factor into how much power generators cost.
Families should weigh the upfront price against the long-term value. At Grounded Electric, Bobby Mulholland and Barret Abramow provide expert guidance to homeowners seeking reliable backup power.
Whether you need a home standby generator, portable unit, or complete installation, our licensed team delivers safe, code-compliant service and peace of mind. Call Grounded Electric Today.
