One of the most important decisions when installing a standby generator in Indiana is choosing your fuel source: natural gas or propane (LP). Both fuel types power the same generators — most Generac, Kohler, and Briggs & Stratton models are dual-fuel capable — but the right choice depends on your location, existing utility connections, and long-term cost preferences.
Here's a detailed comparison to help Hamilton County homeowners make the right call.
Natural Gas Generators: The Convenient Choice
Natural gas is the most popular fuel choice for standby generators in Carmel, Fishers, and the established neighborhoods of Hamilton County. And for good reason — if you already have a natural gas line to your home, it's almost always the simpler and more cost-effective option.
How Natural Gas Generators Work
A natural gas generator connects directly to your home's existing gas supply through a dedicated line run from your gas meter. During an outage, the generator draws fuel continuously from the municipal gas supply — which means you never run out of fuel, no matter how long the outage lasts.
In Hamilton County, natural gas is supplied primarily by CenterPoint Energy (serving most of Carmel 46032, Fishers 46038, and Westfield 46074) and Citizens Gas in some areas.
Natural Gas Advantages
- Unlimited fuel supply — Gas lines rarely go down during storms, so you have continuous power
- No fuel storage — No tank to maintain, refill, or make room for on your property
- Lower installation cost — Running a gas line from your existing meter typically costs $500-$1,200, compared to $2,000-$4,000+ for a propane tank and line
- Lower ongoing fuel cost — Natural gas in Indiana averages $1.00-$1.30 per therm; running a 20kW generator costs roughly $3-$5 per hour
- Cleaner burning — Produces fewer emissions than propane
- HOA-friendly — No visible tank; popular in Carmel HOA communities like WestClay, Springmill, and Brookshire
Natural Gas Limitations
- Lower energy density — Natural gas produces about 1,030 BTU per cubic foot vs. propane's 2,490 BTU per gallon, meaning the generator works slightly harder for the same output
- Pressure-dependent — During extreme cold snaps, gas pressure can drop if demand spikes across the grid (rare but possible in Indiana winters)
- Not available everywhere — Rural areas of northern Hamilton County, parts of Cicero, and some Westfield properties don't have natural gas service
Propane Generators: The Independent Choice
Propane generators are the go-to option for Indiana homeowners without natural gas access — and they're also preferred by some homeowners who want complete energy independence.
How Propane Generators Work
A propane generator connects to a dedicated propane storage tank on your property. Tanks are typically 250 to 500 gallons for residential standby generators and are installed by a local propane supplier. The generator draws fuel as needed during an outage.
Propane Advantages
- Available anywhere — No utility connection required. Perfect for rural Cicero, northern Westfield, and properties outside natural gas service areas
- Higher energy density — Propane packs more energy per unit, meaning slightly better generator efficiency
- Long shelf life — Propane doesn't degrade over time (unlike gasoline or diesel), so stored fuel stays ready indefinitely
- Energy independence — You own your fuel supply and aren't dependent on utility infrastructure
- Strong performance in cold weather — Propane maintains consistent pressure even in Indiana's sub-zero temperatures
Propane Limitations
- Finite fuel supply — A 500-gallon tank running a 20kW generator at half load lasts roughly 4-5 days. Extended outages require refill scheduling.
- Higher upfront cost — Tank purchase/lease ($800-$2,500) plus installation ($1,000-$2,000) adds to the project
- Ongoing refill costs — Propane in Indiana averages $2.00-$3.00 per gallon; running a 20kW generator costs roughly $4-$7 per hour
- Tank space requirements — A 500-gallon tank is roughly 10 feet long and needs code-compliant setbacks from structures
- Delivery dependency — During widespread outages or winter storms, propane delivery trucks may face delays
Side-by-Side Comparison
| Factor | Natural Gas | Propane |
|---|---|---|
| Fuel availability | Continuous (utility) | Tank-limited |
| Fuel cost per hour (20kW) | $3-$5 | $4-$7 |
| Installation cost premium | $500-$1,200 (gas line) | $1,800-$4,500 (tank + line) |
| Fuel storage needed | No | Yes (250-500 gal tank) |
| Available in rural areas | No | Yes |
| Cold weather performance | Good (rare pressure drops) | Excellent |
| Environmental impact | Lower emissions | Slightly higher emissions |
| HOA compatibility | Excellent (no tank) | Varies (tank visibility) |
Which Should You Choose in Hamilton County?
The decision usually comes down to one simple question: do you have natural gas service at your property?
Choose Natural Gas If:
- You already have natural gas service (most of Carmel, Fishers, and central Westfield)
- You live in an HOA community that restricts propane tanks
- You want the lowest total cost of ownership
- You prefer zero fuel management (no refills, no delivery scheduling)
Choose Propane If:
- Your property doesn't have natural gas access (rural Cicero, northern Westfield, parts of Noblesville)
- You want complete independence from utility infrastructure
- You're in an area with unreliable natural gas pressure during peak demand
- You already have a propane tank for other home systems (heating, cooking, pool)
Dual-Fuel: The Best of Both Worlds
Many modern generators — including the popular Generac Guardian series — come dual-fuel capable, meaning they can run on either natural gas or propane. This is especially valuable if you're on natural gas now but want the option to add a propane backup tank later, or if you're building in an area where natural gas service might be extended in the future.
Fuel Costs: What to Budget Annually
Beyond installation, your fuel costs depend on how often your generator runs. For Hamilton County, where most homeowners experience 2-5 outages per year totaling 10-30 hours of runtime:
- Natural gas annual fuel cost: $30-$150 (plus $20-$40/year for weekly exercise tests)
- Propane annual fuel cost: $40-$210 (plus one tank top-off per year, ~$150-$300)
In most scenarios, natural gas saves $100-$300 per year over propane for Hamilton County homeowners.
Get Expert Guidance on Fuel Type
Still not sure which fuel source makes sense for your home? A qualified local installer can assess your gas service, property layout, and power needs to recommend the best option.
Request Your Free Generator Assessment →
We'll connect you with a vetted Hamilton County installer who can evaluate both fuel options for your specific situation — free, no obligation.