Natural Gas vs Propane Standby Generators

When a Lowcountry summer storm or a full-blown hurricane knocks out the grid, the fuel feeding your standby generator decides how long you stay powered. The two practical choices for Charleston-area homes are natural gas and propane. Both run quiet, automatic whole-house generators well, but they behave very differently depending on where you live, how the gas infrastructure reaches your street, and what you expect during a multi-day outage.

This guide breaks down how each fuel works, the honest trade-offs, and how the choice tends to shake out across the metro, from downtown peninsula homes to rural acreage in Berkeley and Dorchester counties.

A quick note on who we are: Lowcountry Generator Pros is a resource that connects homeowners with a single vetted local installer. We are not a contractor and we do not run a directory of paid reviews. The goal here is to help you walk into that conversation already knowing the right questions.

How each fuel actually works

Natural gas comes to your home through a buried utility main, the same line that might already feed a gas range, water heater, or furnace. In much of the urbanized core, that service is provided by Dominion Energy South Carolina. A natural gas standby generator taps into that supply, so it never runs out as long as the utility’s system stays pressurized. There is no tank to fill, monitor, or refill.

Propane (LP) is stored on your property in a tank, usually a 250 to 1,000 gallon above-ground or buried tank sized for the generator and any other propane appliances. The generator draws vapor from that tank. When the tank gets low, a delivery truck refills it. You own (or lease) a finite, on-site fuel reserve rather than relying on a pipeline.

The pros and cons, plainly

Natural gas

Strengths:

• Effectively unlimited runtime during a normal outage, no tank to drain.
• No fuel to store or schedule deliveries for, and no tank taking up yard space.
• Lower per-unit fuel cost in most years.
• Nothing to “go stale” the way stored fuel can.

Weaknesses:

• You must have a natural gas main on your street and adequate service capacity. Plenty of Lowcountry properties do not.
• It depends on the utility staying up. This is rare, but severe events that damage gas infrastructure, or a planned shutoff, can interrupt supply.
• Generators typically produce slightly lower power output on natural gas than on propane, which can nudge you toward a larger unit.

Propane

Strengths:

• Total fuel independence. Your reserve sits on your own land, immune to whatever happens to the pipeline grid.
• Works anywhere, including rural lots with no gas main for miles.
• Higher energy density, so the same generator often delivers a bit more output.
• Stores for years without meaningful degradation when kept in a proper tank.

Weaknesses:

• Finite supply. A long outage can drain a tank, and you are then dependent on a delivery truck reaching you, which is exactly when roads may be flooded or blocked.
• Upfront and ongoing cost of the tank plus periodic refills.
• Tank footprint and placement rules, including setbacks and flood considerations.

Runtime in a real hurricane outage

This is where Lowcountry geography matters more than spec sheets. We have a long memory of Hurricane Hugo in 1989 and the multi-day, sometimes multi-week recovery that followed in the hardest-hit areas. When you plan for the Lowcountry, you plan for the long outage, not the afternoon flicker.

A natural gas unit can theoretically run for as long as the outage lasts, which is its biggest advantage. The catch is that you are trusting the gas system to stay intact through the same storm that took down the power.

A propane unit’s runtime is simple math: tank size, generator size, and how hard you load it. A right-sized whole-house generator running typical loads will burn through a meaningful share of a large tank over several days. Many rural homeowners size the tank deliberately large, or keep it topped off heading into hurricane season, precisely so they are not waiting on a delivery during the worst of it. To get the math right for your home, start with how to size a home standby generator, then talk through tank sizing with the installer.

Charleston-area reality: who gets which

The honest answer for most homeowners comes down to one question: does a natural gas main reach your property with enough capacity?

• In town and in established neighborhoods across Charleston, and parts of Goose Creek and Summerville, Dominion Energy SC service is often already at the curb. If you have gas service, natural gas is usually the path of least resistance: no tank, no refills, lower fuel cost. The installer confirms the meter and line can handle the added load.

• In rural Berkeley and Dorchester counties, where gas mains simply do not run down many roads, propane is frequently the only viable option, and a perfectly good one. Acreage, well-and-septic homes, and newer construction outside the gas footprint are classic propane candidates.

• On the line between the two, the decision often hinges on what extending or upgrading a gas line would cost versus installing a tank. That is a site-specific call the installer makes after looking at your meter, your loads, and your lot.

There is also the flooding angle. In tidal and low-lying areas, both the generator and a propane tank need to sit on properly elevated, flood-conscious footing. That is part of a good site assessment regardless of fuel.

So which should you choose?

A simple way to think about it:

• Already have Dominion Energy SC natural gas service with capacity? Natural gas is usually the easy, low-hassle winner, set it and forget it.
• No gas main, or rural property in Berkeley/Dorchester? Propane, sized generously for a long outage.
• On the fence? Let the installer price both. The fuel decision should follow the site, not the other way around.

You can compare both fuels side by side on the fuel section of our home page. When you are ready, we will connect you with the vetted local installer who can walk your property, confirm what is actually available at your address, and recommend the fuel and unit that fit your home and budget.