Tennessee: 65 cities covered
Across 65 Tennessee cities with a positive case for switching, the average incremental payback is about 31.9 years against a like-for-like gas furnace replacement — but that average hides real spread, which is why each city gets its own page rather than one statewide number.
- Nashville-Davidson — 704,963 people, 2807 HDD
- Memphis — 610,919 people, 2396 HDD
- Knoxville — 198,722 people, 3096 HDD
- Chattanooga — 191,496 people, 2547 HDD
- Clarksville — 185,690 people, 2988 HDD
- Murfreesboro — 168,387 people, 3001 HDD
- Franklin — 89,142 people, 2670 HDD
- Johnson City — 73,635 people, 3585 HDD
- Jackson — 69,303 people, 2708 HDD
- Hendersonville — 63,947 people, 2670 HDD
- Smyrna — 60,302 people, 3001 HDD
- Spring Hill — 59,398 people, 3098 HDD
- Kingsport — 57,109 people, 3585 HDD
- Bartlett — 56,708 people, 2515 HDD
- Gallatin — 52,489 people, 2670 HDD
- Collierville — 51,951 people, 2525 HDD
- Lebanon — 51,501 people, 3001 HDD
- Cleveland — 50,232 people, 2547 HDD
- Columbia — 48,812 people, 3098 HDD
- Brentwood — 45,525 people, 2670 HDD
- Mount Juliet — 44,066 people, 2670 HDD
- La Vergne — 41,430 people, 3001 HDD
- Germantown — 40,128 people, 2525 HDD
- Cookeville — 37,102 people, 3395 HDD
- Oak Ridge — 34,039 people, 3090 HDD
- Morristown — 32,994 people, 2456 HDD
- Maryville — 32,373 people, 2992 HDD
- Bristol — 27,867 people, 3585 HDD
- Shelbyville — 25,792 people, 3125 HDD
- Farragut — 25,242 people, 3090 HDD
- East Ridge — 21,970 people, 2547 HDD
- Tullahoma — 21,035 people, 3125 HDD
- Springfield — 19,842 people, 2807 HDD
- Sevierville — 18,231 people, 3096 HDD
- Goodlettsville — 17,433 people, 2807 HDD
- Dickson — 16,878 people, 2807 HDD
- White House — 16,463 people, 2807 HDD
- Greeneville — 15,979 people, 3585 HDD
- Dyersburg — 15,915 people, 2295 HDD
- Nolensville — 15,809 people, 3001 HDD
- Arlington — 15,550 people, 2515 HDD
- Athens — 15,050 people, 2992 HDD
- Elizabethton — 14,461 people, 3585 HDD
- Lakeland — 14,416 people, 2515 HDD
- McMinnville — 14,032 people, 3395 HDD
- Portland — 13,651 people, 3009 HDD
- Alcoa — 13,588 people, 2992 HDD
- Manchester — 13,484 people, 3125 HDD
- Lewisburg — 13,473 people, 3098 HDD
- Soddy-Daisy — 13,430 people, 2547 HDD
- Crossville — 12,785 people, 3659 HDD
- Hartsville/Trousdale County — 12,159 people, 3001 HDD
- Lawrenceburg — 12,112 people, 3098 HDD
- Red Bank — 12,073 people, 2547 HDD
- Lenoir City — 12,041 people, 3090 HDD
- Collegedale — 11,510 people, 2547 HDD
- Millington — 11,486 people, 2515 HDD
- Martin — 10,989 people, 1702 HDD
- Union City — 10,876 people, 1702 HDD
- Oakland — 10,769 people, 2515 HDD
- Atoka — 10,624 people, 2515 HDD
- Fairview — 10,535 people, 2807 HDD
- Paris — 10,517 people, 3095 HDD
- Clinton — 10,458 people, 3090 HDD
- Winchester — 10,251 people, 3125 HDD