Natural Gas vs. Propane Generator: Which Should You Choose?

For most Jacksonville-area homes that have natural gas service, natural gas is the better fuel for a home standby generator — cheaper fuel cost, no tank to maintain, effectively unlimited runtime during outages, and one less thing to top off before hurricane season. For homes without natural gas service (large parts of rural St. Johns, sections of Clay and Nassau, some outlying Duval areas), propane is the standard alternative and works fine.

The choice usually comes down to whether your address has natural gas service. The tradeoffs only become interesting at the edges.

Natural gas: the default for Jacksonville homes that have it

If TECO Peoples Gas or another natural gas utility serves your address, natural gas wins on most dimensions:

Cost per kWh generated. Natural gas in Northeast Florida runs roughly 40–60% cheaper per BTU than residential propane in 2026. For a 22kW generator running 50% load over a 5-day outage, the fuel cost difference is $100–$400.

No tank to maintain or top off. A propane installation requires a 250-gallon (or larger) tank set on your property. Natural gas just uses your existing meter. Less paperwork, less HOA review, less yard impact.

Continuous runtime during outages. Natural gas pressure is maintained underground regardless of weather conditions. Propane runtime is bounded by your tank capacity — once it's empty, you're done until a refill (which is hard to schedule during a hurricane week).

No pre-storm planning required. Natural gas customers don't need to schedule a propane top-off in May or check tank levels before a named storm. The fuel is just there.

Lower install complexity. Natural gas tie-in is one trade. Propane install includes a separate tank set with its own permitting, excavation, and fire-marshal sign-off.

Propane: the right call when natural gas isn't available

If your address doesn't have natural gas service, propane is the standard fuel choice for home standby. It works well — millions of propane home standby units run reliably across the U.S. — but it has different ownership characteristics:

Tank sizing matters. A 250-gallon underground tank running a 20kW generator at typical 50% home load lasts 4-6 days. A 500-gallon tank lasts 8-12 days. Most Northeast Florida installs default to 500-gallon for hurricane-season runtime headroom.

Above-ground vs. underground tanks. Underground tanks ($1,000-$2,500 more) are more expensive but visually invisible and HOA-friendly. Above-ground tanks are cheaper but visible — most Mandarin, Nocatee, and Ponte Vedra HOAs require underground.

Refill scheduling is real. Propane suppliers can be hard to schedule during the days leading up to a major storm. Pre-season top-off (by mid-May) eliminates this problem.

Propane price volatility. Residential propane prices in Northeast Florida fluctuate seasonally — typically lower in spring/summer, higher in winter. Top off when prices are lower.

No utility dependency. Propane is independent of any utility. If TECO Peoples Gas had a major outage (extremely rare but theoretically possible), propane would still flow.

Diesel: rarely the right call for residential

A few homeowners ask about diesel home standby. Honest answer: diesel rarely makes sense for residential under 25kW. Where diesel wins:

• 30kW+ commercial applications
• Run-time-critical applications (some medical, server backup at home offices)

Where diesel doesn't win for residential:

• Higher unit cost
• Diesel storage is more complicated than propane
• Fuel polishing required if stored long-term (gel formation in cold)
• Most Jacksonville-area diesel home installs we've seen end up wishing they'd done propane

How to know what your address has

Before quoting, we check:

• Is there a gas meter on the home? If yes, you have natural gas service.
• Is there an existing propane tank? You're already on propane (we may need to upsize for generator load).
• Neither? You'll need to choose: extend natural gas service from the street (sometimes possible, sometimes not, depending on existing infrastructure) OR install propane.

TECO Peoples Gas service maps cover most of urban Duval. Outlying areas in Clay, St. Johns, and Nassau often don't have gas service available — the cost to extend a gas main from the street to a single home is usually prohibitive ($3,000–$15,000+), and propane becomes the more economic path.

Conversion between fuels

Most modern home standby generators (Generac Guardian, Kohler 20RCA-series, etc.) ship as dual-fuel-capable with a field selector. A unit installed on natural gas can be converted to propane in the field with a service visit and a regulator/jet swap. The conversion takes 1-2 hours and runs $200-$400.

This matters in two scenarios:

1. You install on propane now (because no natural gas is available) but your neighborhood gets natural gas service later. Conversion is a quick service visit.
2. You move and want to take the unit to a home with the other fuel type. Same conversion path.

Practically, most home standby generators stay on whichever fuel they were installed with. The option just matters in long-term planning.

What we recommend

Default decision tree:

1. Natural gas available at the address? → Install on natural gas.
2. No natural gas, larger property (over 0.5 acres)? → Install on propane with a 500-gallon underground tank.
3. No natural gas, smaller property? → Install on propane with a 250-gallon underground tank.
4. Significant runtime needs and propane refill access is unreliable? → Consider 1,000-gallon tank for 16-24 day runtime headroom.

Where it gets nuanced is the rural-edge case where natural gas service ends 200 feet from the property line. Sometimes extending the gas main is feasible at moderate cost; usually it isn't. We talk through both paths at the on-site assessment.