Two fuels, one kind of generator
Home standby generators run on gaseous fuel: natural gas or propane (also called LP or liquid propane). Most residential models can be set up for either. The choice usually isn't about preference. It's about what's available at your address.
In eastern North Carolina the split is clear. Natural gas is piped to many homes inside towns and along the main corridors, supplied by Piedmont Natural Gas or, in a few cities, by the city's own gas utility. Out in the county, gas mains are rare, and propane from a tank in the yard is the norm. Eastern NC Generators connects you with a licensed electrical contractor and Generac dealer who installs both.
Natural gas generators
If your house already has natural gas service, it's usually the simplest choice.
Advantages
- Unlimited run time. The gas keeps coming from the main, so there's no tank to watch during a long outage. You only need to keep up with oil checks during very long runs.
- No fuel deliveries. Nothing to schedule before hurricane season.
- Reliable supply in storms. Underground gas distribution is rarely interrupted by wind, though flooding can affect service in some areas.
What it takes
- Meter capacity. Your meter has to supply the generator and your other gas appliances, like a furnace, water heater and range, all at once. Many homes need a larger meter or higher-pressure service, which the gas company provides. The installer calculates the total load and requests the upgrade.
- Correctly sized gas pipe. The line from the meter to the generator has to be sized for the generator's full fuel demand over that distance. An undersized line is one of the most common causes of a generator that starts but can't carry the house.
- Permit and inspection. The gas piping is permitted and inspected along with the electrical work.
Who supplies the gas depends on where you live. Piedmont Natural Gas serves much of the region, including Kinston, Goldsboro and Fayetteville. Rocky Mount, Wilson and Greenville have municipal gas systems. Each town page lists the provider for that area.
Propane generators
Propane works anywhere a truck can reach a tank, which is why it's the standard fuel for standby generators in rural eastern NC and in many coastal communities.
Advantages
- Available everywhere. No gas main needed.
- Fuel on site. The tank is on your property, so the generator doesn't depend on any outside supply during the storm.
- Stores well. Propane doesn't go stale the way gasoline does, so a full tank in June is still good in October.
What it takes
- A tank sized for run time. Common residential tank sizes include 250, 500 and 1,000 gallons. Tanks are filled to about 80 percent to leave room for expansion. How long a full tank lasts depends on the generator size and how much of the house it's carrying. The installer will estimate days of run time for your setup so you can pick a tank that covers a long outage.
- A tank above or below ground. Above-ground tanks cost less to install. Underground tanks keep the yard clear but cost more. In flood zones, tanks have to be anchored so they can't float.
- A propane supplier. Many households lease their tank from a propane company; others own it. If you already have propane for heat or cooking, your existing tank may be big enough, or the supplier may swap it for a larger one.
- Regulators and piping. The line from the tank to the generator is sized and regulated for the generator's demand, and inspected.
Choosing between them
| Natural gas | Propane | |
|---|---|---|
| Availability | Only where gas service reaches | Anywhere a delivery truck can reach |
| Run time | Unlimited while gas supply holds | Depends on tank size and load |
| Up-front extras | Possible meter upgrade, gas line | Tank, regulators, gas line |
| Ongoing | Gas billed with your regular service | Tank refills, possible tank lease |
| Storm prep | Nothing to do | Top off the tank before hurricane season |
If you have natural gas at the house, it's usually the easiest route. If you don't, getting gas service extended for a generator is rarely practical, and propane is the answer.
How installation works
Site visit
An installer walks the property, looks at your electrical panel and gas or propane setup, and picks a spot for the unit that meets clearance and flood rules.
Sizing
You decide what should run during an outage, from a few essential circuits to the whole house. That choice sets the generator size and the transfer switch.
Permit
The contractor pulls the electrical permit, and a gas or plumbing permit where needed, from the city or county that covers your address.
Gas line or propane tank
Natural gas homes may need a meter upgrade from the gas company. Propane homes get a tank sized for multi-day run time and a line to the unit.
Installation
The pad is set, the generator is placed and the transfer switch is wired into your panel. Most residential installs take one to two days on site.
Inspection and startup
The local inspector signs off, the unit is started and tested under load, and you are shown how it exercises itself and how to check it.
Propane tips for hurricane season
- Fill early. Ask your supplier to top off the tank in late spring, before the season starts and before storm-driven demand.
- Keep it full. If a storm is forecast, check the gauge and call for a delivery early. Roads may close after landfall.
- Anchor the tank. In flood-prone yards, make sure the tank is secured so it can't move or float.
- Clear the area. Keep the tank and regulator free of debris and visible for delivery drivers.
Converting an existing generator
Many standby generators can be converted between natural gas and propane with a kit and adjustments, for example if gas service arrives on your road. The fuel change should be done by a qualified technician and the new connection inspected.
Areas we cover
Propane and natural gas generator installation is available across eastern North Carolina, including Kinston, Goldsboro, Rocky Mount, Washington, Havelock, Greenville, New Bern, Jacksonville, and Wilson. See the full service area, or read more about whole house generators.
Common questions
Is natural gas or propane better for a generator?
Natural gas is usually simpler if you already have it, because it never runs out. Propane works anywhere and keeps the fuel on your property. Your address usually decides it.
How long will a propane generator run?
It depends on the tank size, how full it is, the generator size and how much of the house is running. The installer estimates days of run time for your setup and recommends a tank that covers a long outage.
Do I need a new gas meter for a generator?
Often. The meter has to supply the generator and all your other gas appliances at once. The installer calculates the load and coordinates any upgrade with the gas company.
Can I use my existing propane tank?
Sometimes. If the tank is large enough for the generator plus your other propane appliances, it can be shared. If not, your supplier can usually swap it for a larger tank.
Does a generator run on gasoline or diesel?
Home standby generators run on natural gas or propane. Some larger commercial generators run on diesel. Portable generators usually run on gasoline.
What happens if my propane runs low during an outage?
The generator shuts down when the fuel runs out. Watch the gauge during long outages and call your supplier early. A larger tank or reduced load stretches run time.