Scenario: a $125/month electric bill. Assumes 3%/yr rate increases, 0.5%/yr panel degradation and no federal tax credit (the 30% §25D credit ended for systems installed after Dec 31, 2025). How we calculate
Data approachEIA rates · NREL sun hours · 2026 federal policy · methodology
A $125/month electricity bill in Tennessee represents roughly 901 kWh per month at the state average rate of 13.87¢/kWh (EIA, Jan–Jul 2026 year-to-date). With 5.0 peak sun hours per day, offsetting that usage takes about a 7.2 kW solar system — roughly 18 panels at 400W — costing about $21,700 installed. Because the 30% federal tax credit ended for systems installed after 2025 and Tennessee has no statewide net metering — utility-dependent, simple payback is about 26.3 years, with an estimated $6,400 net over 25 years.
How Many Solar Panels for a $125 Electric Bill in Tennessee?
Tennessee electricity rates and sun hours change the math versus the US average. The sizing formula:
System size (kW) = Annual kWh ÷ (Peak sun hours × 365 × 0.82)
For a $125/month bill in Tennessee:
Annual usage: ~10,815 kWh/year
Peak sun hours: 5.0 h/day (Tennessee)
System size:7.2 kW DC (~18 × 400W panels)
Metric
Tennessee
US average
Rate
13.87¢/kWh
18.19¢/kWh
Sun hours
5.0 h/day
4.5 h/day
System size
7.2 kW
6.1 kW
Panels (400W)
18
16
Tennessee requires a larger system than the national average for the same dollar bill because higher consumption at lower rates. Use our solar system size calculator with your ZIP code for a roof-specific result.
Run the numbers for your state
The savings calculator loads your state's average electricity rate, sun hours and net-metering rule. Then enter your own bill and installer quote.
Free · No signup · Runs in your browser
💰 System Cost
What Does Solar Cost for a $125/Month Bill in Tennessee in 2026?
At about $3.00/W installed (a blended 2026 US price; marketplace quotes often run lower), a 7.2 kW system in Tennessee costs about $21,700.
The 30% federal Residential Clean Energy Credit (IRC §25D) ended for systems installed after December 31, 2025, so a solar system you buy and install in 2026 gets no federal tax credit. Leases and PPAs are different: the installer that owns the system can still claim the commercial §48E credit for systems placed in service by the end of 2027 and may pass part of that value on through a lower monthly price.
Cost line
Amount
Installed cost (7.2 kW)
$21,700
Federal credit (25D) for 2026 installs
$0
Your cost before state/local incentives
$21,700
Getting three or more quotes matters more than ever without the federal credit: installed prices for the same system often differ by 20–30%.
📈 Payback Period
How Long Is Solar Payback on a $125 Bill in Tennessee?
Simple payback divides installed cost by first-year bill savings. Most of Tennessee is TVA territory with no retail net metering; exports are credited at a low wholesale-based rate. We therefore assume solar offsets about 55% of a $125/month bill in Tennessee — roughly $825/year — for a simple payback of about 26.3 years.
Over 25 years, with 3% annual rate increases and 0.5%/year panel degradation, cumulative bill savings minus the installed cost come to about $6,400. Because exported power earns little in Tennessee, a smaller system sized to your daytime use, or solar paired with a battery, usually pays back faster than a system sized to 100% of annual usage. Model your own numbers in our solar payback calculator.
Solar vs utility company · 25-year comparison
25-year totals for a $125/month electric bill: 3%/yr rate increases, 0.5%/yr degradation, no federal credit. Methodology
Tennessee Solar Incentives for a $125/Month Electric Bill
State and local incentives: Tennessee has no state solar tax credit or statewide rebate program.
Net metering: Most of Tennessee is TVA territory with no retail net metering; exports are credited at a low wholesale-based rate.
Check DSIRE and our Tennessee solar page for current rebates, net metering rules, and utility-specific programs before signing an install contract.
⚡ System Size
Tennessee vs US Average: $125/Month Bill Comparison
Tennessee
US average
Monthly bill
$125
$125
System size
7.2 kW
6.1 kW
Installed cost
$21,700
$18,400
Bill offset assumed
55%
75% (blended)
Simple payback
26.3 yrs
16.3 yrs
25-year net savings
$6,400
$20,000
Bottom line: A $125/month bill in Tennessee is a weak solar candidate with about 26.3-year payback in 2026. Calculate your Tennessee savings or compare all states on the $125 bill hub.
Related calculators
Free tools for US homeowners — instant results, all 50 states.
At Tennessee's average rate of 13.87¢/kWh and 5.0 peak sun hours, a $125/month bill (~10,815 kWh/year) typically requires a 7.2 kW system — about 18 panels at 400W each. Use our solar system size calculator with your ZIP for a roof-specific estimate.
A 7.2 kW system in Tennessee costs roughly $21,700 installed at about $3.00 per watt. The 30% federal tax credit (25D) ended for systems installed after December 31, 2025, so there is no federal credit for a system you buy in 2026. Tennessee has no state solar tax credit or statewide rebate program.
At $21,700 installed and ~$825/year in bill savings, simple payback in Tennessee is about 26.3 years. Most of Tennessee is TVA territory with no retail net metering; exports are credited at a low wholesale-based rate.
With about 26.3-year payback and roughly $6,400 in estimated 25-year net savings, a $125/month bill in Tennessee is a weak case for buying solar in 2026. Consider a smaller system, a battery, or a lease/PPA quote, and compare against efficiency upgrades first. See the [Tennessee solar page](/states/tn/) for net metering and incentive details.
The US average needs a 6.1 kW system at 16.3-year payback. Tennessee needs 7.2 kW with 26.3-year payback — driven by Tennessee's 13.87¢/kWh rate and 5.0 daily sun hours.
13.87¢/kWh — Tennessee average residential price. Source: EIA Electric Power Monthly, Table 5.6.B (year-to-date through July 2026), residential average retail price (July 2026) (EIA)
Solar production
5 peak sun hours/day × 0.82 system derate. Approximate state-average daily solar resource (peak sun hours) based on NREL solar resource data (NSRDB); not location-specific — use NREL PVWatts for an address-level estimate. (NREL PVWatts)
Installed price
$3.00 per watt before incentives. Blended 2026 US residential installed price used by this site; EnergySage marketplace reported about $2.60/W (mid-2026); full-market medians are higher.
Federal tax credit
$0 for homeowner-owned systems installed in 2026 — the 30% §25D credit ended Dec 31, 2025 (IRS)
Net metering
No statewide net metering — utility-dependent — solar assumed to offset 55% of the bill. Most of Tennessee is TVA territory with no retail net metering; exports are credited at a low wholesale-based rate.
Estimates only — not tax, legal or financial advice. Get at least three installer quotes and confirm incentives with your utility and a tax professional.