6 truths about high Piedmont Natural Gas bills. Will Iran war raise prices further?
Some Charlotte-area residents were shocked when their natural gas bills arrived this winter.
Customers across the region told The Charlotte Observer their Piedmont Natural Gas bills were hundreds of dollars higher than they expected for January, with some topping $500, $700 or even $900. The complaints prompted questions from readers about whether rising prices, colder weather or something else was behind the spike.
Piedmont Natural Gas, which is owned by Duke Energy, has attributed the higher bills largely to rising natural gas prices and winter heating demand. But a closer look at rate filings, regulatory data and billing factors shows several variables can influence what customers ultimately pay.
Here are six things customers should know about why some bills increased and how gas rates work in North Carolina.
How much gas prices rose
The price customers pay for natural gas has climbed significantly over the past two years.
According to Jason Wheatley, communications manager for Piedmont Natural Gas, the total residential rate per therm — which includes the cost of gas plus distribution and fees, but not fixed monthly charges or taxes — increased from about $1.43 per therm in January 2024 to $2.16 per therm in January 2026.
That means a household using the same amount of natural gas as 2024, or 2025 when the cost was $1.78 per therm, could still see a noticeably higher bill.
For example, a home using 100 therms would have paid about $143 for the gas itself in January 2024, compared with roughly $216 for the same amount this January before fixed charges and taxes.
The Henry Hub benchmark, the primary pricing index for the North American natural gas market, shows prices have risen from $2.27 per unit in 2024 to $5.04 in 2026.
Why gas bills increased
Wheatley said most of the increase in customer bills is tied to rising natural gas costs.
On average, PNG customers paid 20% more this winter than the year prior. According to Wheatley, roughly 92% of that year-over-year increase in customer bills is attributable to higher natural gas costs rather than increased usage or any other factor.
The company purchases natural gas from the Transco and Columbia Gas Transmission pipelines connected to major shale production regions, including the Marcellus and Utica deposits which stretch from West Virginia to Canada and the Haynesville deposit which spans Texas, Louisiana and Arkansas.
The conflict involving Iran has also affected global energy markets. An estimated 20% of the world’s oil supply has been disrupted by the ongoing conflict, CNN reported. In the U.S., natural gas futures prices have risen since the start of the conflict, according to Piedmont Natural Gas, though the company said colder-than-normal weather forecasts are likely the larger driver of the increase.
The natural gas delivered to Piedmont customers is primarily produced in the United States and transported through interstate pipelines to North Carolina.
“Piedmont Natural Gas has access to a liquid and geographically diverse portfolio of both storage and pipeline transportation capacity, which helps provide our customers with best-cost physical natural gas supplies to mitigate any short-term price increases,” Wheatley said.
Natural gas prices have risen since early 2024 due to several factors, according to Piedmont:
- Increased winter heating demand
- Growing exports of liquefied natural gas to Europe and Asia
- Pipeline capacity constraints
- Storage and supply fluctuations
Those price increases are passed “directly to customers dollar-for-dollar,” Wheatley said.
Cold weather wasn’t the only factor
Initially, PNG told the Observer the increase in gas bills was largely attributable to high winter heating costs.
Utilities often track this using heating degree days, a metric that measures how much outdoor temperatures fall below 65 degrees, the point when buildings generally begin requiring heat. The more HDDs, the colder the temperatures and the more fuel required.
Piedmont’s data shows the overall winter season was colder in several months compared with the previous winter, though the differences varied by month.
This winter PNG reported 2,374 HDDs, compared to 2,188 last winter. This February had more HDDs than last year, and January had fewer.
However, weather alone does not explain the full increase. Piedmont reported the average residential customer actually used slightly less natural gas in January, about 104 therms, compared with 111 therms in January 2024.
Customers could see relief as temperatures warm up for spring, as heating homes is the primary use of gas for many households.
Piedmont’s last rate case
Piedmont Natural Gas is a regulated utility in North Carolina, meaning its rates and pricing structure are overseen by the North Carolina Utilities Commission.
Under state law, utilities must seek approval from the commission to change their base rates or add new charges. The commission reviews those requests through formal rate cases that include financial data and public hearings.
Piedmont’s most recent general rate case in North Carolina was approved by the Utilities Commission and took effect beginning Nov. 1, 2024. The increase costs an average residential customer $90 more per year, Duke Energy said.
Piedmont’s net annual revenue increased by $88 million with the change. The approved rate case authorized a 9.8% return on equity — the profit level regulators allow utilities to earn.
“Raising rates is never a decision Piedmont takes lightly, and these investments in strengthening and enhancing our natural gas delivery system ensure we continue to provide safe, reliable service to our North Carolina customers while meeting the rising demand for natural gas throughout our service area,” Wheatley said in an email.
Base residential service charges remained at $10 per month.
What to do if your bill seems wrong
Customers who believe their bill may be inaccurate should first contact Piedmont Natural Gas at 800-752-7504 directly to review the charges.
PNG said it has seen a 14% increase in customer bill complaints from last winter to this winter.
The utility said its billing system flags unusual consumption patterns and potential meter irregularities for review. Piedmont also periodically replaces or inspects meters as part of normal maintenance. There has not been any increase in billing irregularities related to meter replacements this winter, Wheatley said.
Fewer than 1% of bills are based on estimated meter readings rather than actual readings, he said.
If customers are not satisfied with the response from the utility, they can file a formal complaint with the North Carolina Utilities Commission, which has authority to review disputes involving regulated utilities and determine whether rates or practices are unjust, unreasonable, or illegal. The commission heard one formal complaint about Piedmont in 2025, and none this year.
Ways to lower your gas bill
Energy use can vary widely depending on home size, insulation, thermostat settings and the number of gas appliances. Piedmont recommends several steps customers can take to reduce natural gas consumption:
- Reduce energy use
- Seal air leaks
- Improve insulation
- Maintain heating systems and appliances
- Use programmable or smart thermostats
Piedmont also encourages customers to explore payment and assistance programs. Its Equal Payment Plan spreads gas costs evenly across the year to help avoid winter spikes, and some households may qualify for aid through programs such as Share the Warmth or the federal Low Income Home Energy Assistance Program.
This story was originally published March 10, 2026 at 5:00 AM.
