Kentucky: 42 cities covered
Across 42 Kentucky cities with a positive case for switching, the average incremental payback is about 20.9 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.
- Louisville/Jefferson County — 640,796 people, 3632 HDD
- Lexington-Fayette urban county — 329,437 people, 3494 HDD
- Bowling Green — 79,076 people, 3009 HDD
- Owensboro — 60,675 people, 3430 HDD
- Covington — 41,611 people, 3923 HDD
- Georgetown — 40,518 people, 3494 HDD
- Richmond — 39,581 people, 3594 HDD
- Elizabethtown — 34,565 people, 3742 HDD
- Florence — 33,763 people, 4009 HDD
- Nicholasville — 33,458 people, 3494 HDD
- Hopkinsville — 30,800 people, 2996 HDD
- Independence — 30,196 people, 4009 HDD
- Jeffersontown — 29,388 people, 3632 HDD
- Frankfort — 28,610 people, 3672 HDD
- Henderson — 27,750 people, 3662 HDD
- Paducah — 26,712 people, 3070 HDD
- Radcliff — 22,706 people, 3554 HDD
- Ashland — 21,066 people, 3422 HDD
- Erlanger — 20,172 people, 4009 HDD
- Madisonville — 19,502 people, 3325 HDD
- Winchester — 19,413 people, 3924 HDD
- Mount Washington — 18,863 people, 3192 HDD
- Murray — 18,567 people, 3095 HDD
- Shelbyville — 18,048 people, 3672 HDD
- St. Matthews — 17,806 people, 3632 HDD
- Danville — 17,562 people, 3943 HDD
- Fort Thomas — 16,914 people, 3923 HDD
- Berea — 16,436 people, 3594 HDD
- Shively — 15,850 people, 3192 HDD
- Glasgow — 15,388 people, 3487 HDD
- Shepherdsville — 14,837 people, 3192 HDD
- Bardstown — 14,104 people, 3507 HDD
- Newport — 13,792 people, 3923 HDD
- Somerset — 12,389 people, 3374 HDD
- Lawrenceburg — 12,189 people, 3871 HDD
- Campbellsville — 11,820 people, 3550 HDD
- Lyndon — 11,221 people, 3632 HDD
- Alexandria — 10,819 people, 3923 HDD
- Versailles — 10,656 people, 3871 HDD
- La Grange — 10,541 people, 3632 HDD
- Franklin — 10,524 people, 3009 HDD
- Paris — 10,185 people, 3924 HDD