Capital Program Planning for Tennessee Gas Utilities

by | Oct 21, 2026

Tennessee · Natural Gas Utilities

Tennessee's gas systems are changing hands and adding customers at the same time. Your capital plan is where that lands.

The Nashville-area LDC just moved from Duke to Spire, residential gas connections keep climbing, and nearly every therm still arrives on an out-of-state pipeline into a winter-peaking system. Each of those forces reshuffles the projects on your list. Invizion helps gas utilities re-sequence a capital portfolio in a click — and defend every decision to the commission or the board.

See how Invizion helps utilities See what Tennessee utilities face Download the briefing (PDF)
The bottom line: Tennessee's gas sector is growing and reshuffling at once — the Nashville-area LDC just moved from Duke to Spire, customers keep climbing, and nearly all supply is imported. The utilities that stay ahead will be the ones whose capital plans can re-sequence as fast as ownership, supply, and safety mandates change.
1.25M1
Residential natural gas customers in Tennessee (2024), up from about 1.22M in 2022.
$2.5B2
Proceeds Duke Energy booked selling its Piedmont / Nashville Gas Tennessee business to Spire in 2026.
313,0003
MLGW natural gas customers — one of the largest municipal gas systems in the U.S.
$4.2B4
Atmos Energy's FY2026 company-wide capital plan — 85%+ for safety and reliability — across eight states including Tennessee.

The Tennessee Landscape

Four forces are moving your project list at once

None of these is theoretical, and none of them waits for your next budget cycle. Together they mean the capital plan you approved last year may already be the wrong plan.

Safety — Aging Pipe & Integrity

Leak-prone pipe still sets the replacement clock

Tennessee's LDCs and municipal systems all run under PHMSA's Distribution Integrity Management Program, which obliges operators to find and prioritize replacement of leak-prone bare steel and cast-iron main.5

The scale is visible in how gas capital now flows: Atmos Energy, one of Tennessee's LDCs, is directing more than 85% of a roughly $4.2 billion FY2026 budget to system safety and reliability rather than growth.4 Many of Tennessee's mid-century municipal systems carry their own bare-steel backlogs on top of that.

Demand — Growth vs. the Long Horizon

Growing today, hedging for tomorrow

Unlike coastal states pursuing building electrification, Tennessee's gas load is still expanding — residential customers rose from about 1.22 million in 2022 to roughly 1.25 million in 2024.1

The pressure here is long-horizon and largely federal: methane rules, the economics of RNG and hydrogen blending, and the stranded-asset risk that reshapes a 20–30 year replacement plan even where near-term throughput keeps climbing. Every main you install today is a bet on demand decades out.

Supply — Pipeline-Dependent & Peaky

Almost every therm arrives on someone else's pipeline

Tennessee produces almost no gas of its own — about 2,667 MMcf in 20246 against roughly 403,000 MMcf delivered to consumers that year7 — so effectively all supply rides interstate pipelines into a winter-peaking system.

That exposure lands on bills: the residential price ran from $8.97 per Mcf in 2020 to $12.45 in 2022 through the Winter Storm Uri and Elliott period, eased to $10.75 in 2024, then climbed back toward $11.84 in 2025.8 Design-day and capacity planning is capital planning.

Recovery — Rate Mechanisms & Ownership

New owner, same regulator, same defensibility test

Tennessee's investor-owned LDCs answer to the TPUC,9 which just presided over the largest change to the state's gas map in years: Duke Energy's sale of its Piedmont / Nashville Gas Tennessee business to Spire, closed March 31, 2026 and rebranded that June.10

Duke booked $2,501 million of proceeds and a $368 million gain on the deal.2 Whether recovery runs through an annual rate mechanism or a full case, every dollar of main replacement and growth still has to be justified to the commission.

Who Delivers Tennessee's Gas

Three investor-owned LDCs and one of the country's deepest municipal gas sectors

Tennessee splits between TPUC-regulated investor-owned utilities and a long bench of city- and district-owned gas systems — including one of the largest municipal gas utilities in the United States.

Investor-owned LDCs

Rates & capital recovery regulated by the TPUC

Spire (formerly Nashville Gas / Piedmont) Nashville & middle Tennessee · acquired from Duke, rebranded 202610; Spire serves ~2M customers across four states11
Atmos Energy Tennessee communities · part of a ~3.4M-customer, 8-state gas-only LDC4
Chattanooga Gas ~69,000 customers · Hamilton & Bradley counties · a Southern Company Gas utility12

The Nashville-area system was Piedmont Natural Gas, a Duke Energy company serving more than a million customers across the Carolinas and Tennessee, until Spire's 2026 acquisition.13

Municipal & utility-district systems

Governed by city boards & commissions, not TPUC rates

Memphis Light, Gas & Water (MLGW) ~313,000 gas customers · largest three-service municipal utility in the U.S.3
Knoxville Utilities Board (KUB) Natural gas alongside electric, water, wastewater & fiber · Knoxville / East Tennessee14
Clarksville, Jackson, Morristown & dozens more Tennessee's municipal & utility-district gas systems15

Municipal systems set their own rates, but they face the same PHMSA safety mandates5 and the same interstate-supply exposure as the investor-owned LDCs.

Rate-Setting & Oversight

Every capital dollar has to be defensible

Whether you file with the TPUC or answer to a municipal board, the question is the same: why this project, why now, why at this cost?

  • Tennessee Public Utility Commission (TPUC) — created in 1996, it sets rates and service standards for the state's investor-owned gas utilities and runs the Gas Pipeline Safety Division.9
  • The Duke-to-Spire handover — TPUC oversight framed the transfer of the Nashville-area LDC from Duke Energy to Spire (closed March 31, 2026, rebranded June 1, 2026); Duke recorded $2,501 million in proceeds and a $368 million gain.102
  • Annual rate mechanisms — Tennessee's larger LDCs recover ongoing infrastructure investment through TPUC-approved annual review / rate mechanisms that true up rates between full cases, the state's functional equivalent of an infrastructure surcharge.9
  • Chattanooga Gas, a Southern Company Gas utility serving roughly 69,000 customers in southeast Tennessee, sets its rates through TPUC proceedings.12

Capital & Funding

Where the capital comes from

Tennessee gas capital is recovered mostly through rates, not federal grants — which puts the weight on getting the plan, and its sequencing, right.

  • Rate-based recovery via the TPUC — annual rate mechanisms let Tennessee's investor-owned LDCs recover main replacement and growth capital between full rate cases.9
  • Atmos Energy: ~$4.2B FY2026 capital, more than 85% directed to system safety and reliability across its eight-state footprint, Tennessee included.4
  • $2.5B in transaction capital — Spire's 2026 purchase of the Nashville-area LDC (Duke booked $2,501 million of proceeds and a $368 million gain) resets who owns that system's capital program.210
  • PHMSA safety programs — the federal Natural Gas Distribution Infrastructure Safety & Modernization grant program and PHMSA's integrity-management framework both fund and mandate leak-prone-pipe replacement, a route especially relevant to Tennessee's municipal systems.5

Where Invizion Fits

Turn Tennessee's gas-system decisions into a defensible capital plan

Invizion is scenario-based capital portfolio optimization built for utilities. When a replacement mandate accelerates, throughput forecasts shift, or a decarbonization ruling lands, you don't re-plan by hand for weeks — you model it and decide with a record to stand behind.

1

Model the “what-if” before it's forced on you

A faster main-replacement schedule, a gas-line-extension ban, an RNG mandate — build the scenario and see the impact on the whole portfolio, side by side with today's plan.

2

Re-sequence 500 projects in a click

When priorities move, Invizion re-orders the portfolio automatically — accelerating, stretching, or deferring projects against the constraints you set, not weeks of spreadsheet surgery.

3

Give regulators or your board a defensible record

Every prioritization and trade-off is captured. When you're asked “why this project, why now,” the answer is documented — not reconstructed after the fact.

Tennessee's Gas, In Brief

Questions Tennessee gas leaders are asking

Short, sourced answers — the same facts we dig into with utilities looking at their capital programs.

How many natural gas customers does Tennessee have?
About 1.25 million residential and roughly 141,000 commercial customers as of 2024 — on the order of 1.4 million total across the state.1
Who delivers natural gas in Tennessee?
Investor-owned Spire (the former Piedmont / Nashville Gas), Atmos Energy, and Chattanooga Gas, plus a large municipal sector led by Memphis Light, Gas & Water.103
What happened to Piedmont / Nashville Gas?
Duke Energy sold its Piedmont Natural Gas Tennessee business to Spire, closing March 31, 2026 and rebranding customers June 1, 2026; Duke recorded $2,501 million of proceeds.102
Where does Tennessee's natural gas come from?
Almost entirely interstate pipelines. Tennessee produced only about 2,667 MMcf in 2024 against roughly 403,000 MMcf delivered to consumers, so in-state production covers well under 1% of demand.67
Who regulates gas rates in Tennessee?
The TPUC regulates the investor-owned LDCs; municipal systems such as MLGW and the Knoxville Utilities Board set their rates through their own boards and commissions.914
How does Invizion help Tennessee gas utilities plan capital?
Invizion is scenario-based capital portfolio optimization for utilities. It lets you model how a change of ownership, a supply-cost spike, or an accelerated main-replacement mandate reshuffles your whole project list, re-sequence the portfolio automatically, and keep a defensible record of every decision for the TPUC or your municipal board.

Go Deeper

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About the Author

GB

Guy Barlow

President, Invizion

Guy Barlow leads Invizion, a capital lifecycle management platform for water and wastewater utilities. He has spent two decades at the intersection of utility capital programs, funding, and analytics, helping utilities make faster, more defensible capital decisions.

Explore Further

See how utilities keep capital plans defensible

Invizion helps utilities model, optimize, and defend their capital programs. Explore how it works, or read our latest thinking on capital planning across the utility sector.

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This briefing was last reviewed September 2026.

Sources

  1. U.S. Energy Information Administration — Tennessee natural gas number of consumers (residential 1,252,232, commercial 141,060, industrial 2,553 in 2024). www.eia.gov
  2. Duke Energy Q2 FY2026 Form 10-Q (via StockTitan) — $2,501 million proceeds and $368 million gain on the sale of Piedmont's Tennessee business, 2026. www.stocktitan.net
  3. Memphis Light, Gas and Water (Wikipedia) — more than 313,000 natural gas customers; largest three-service municipal utility in the U.S. with 420,000+ customers. en.wikipedia.org
  4. Atmos Energy — ~3.4 million customers across eight states; ~$4.2B FY2026 capital plan, 85%+ for safety and reliability (Investor Relations / StockTitan). investors.atmosenergy.com
  5. PHMSA — natural gas distribution pipeline safety: Distribution Integrity Management Program and bare-steel / leak-prone pipe inventory reporting by state. www.phmsa.dot.gov
  6. U.S. Energy Information Administration — Tennessee marketed natural gas production (2,667 MMcf in 2024). www.eia.gov
  7. U.S. Energy Information Administration — Tennessee natural gas deliveries to consumers by sector (~403,125 MMcf total in 2024). www.eia.gov
  8. U.S. Energy Information Administration — Tennessee residential natural gas price ($8.97 in 2020, $12.45 in 2022, $10.75 in 2024, $11.84 in 2025, per Mcf). www.eia.gov
  9. Tennessee Public Utility Commission — established 1996; regulates investor-owned natural gas utilities and operates the Gas Pipeline Safety Division. www.tn.gov/tpuc
  10. Spire — "Spire announces new brand in Tennessee": acquired Piedmont Natural Gas's Tennessee business from Duke Energy, closed March 31, 2026, rebranded June 1, 2026, serving Nashville and middle Tennessee. www.spireenergy.com
  11. Spire — company overview: delivers natural gas to nearly 2 million customers across Alabama, Mississippi, Missouri and Tennessee. www.spireenergy.com
  12. Chattanooga Gas — ~69,000 customers in Hamilton and Bradley counties; part of Southern Company Gas since July 2016. www.chattanoogagas.com
  13. Piedmont Natural Gas (Wikipedia) — a Duke Energy subsidiary serving over one million customers across North Carolina, South Carolina and Tennessee. en.wikipedia.org
  14. Knoxville Utilities Board (KUB) — municipal utility providing natural gas along with electric, water, wastewater and fiber service to the Knoxville area. www.kub.org
  15. Tennessee Gas Association — statewide association of Tennessee's natural gas distribution systems, including investor-owned, municipal and utility-district members. www.tngas.org