Solar Panels for a $150/Month Electric Bill
Est. net savings
$24,000
Over 25 Years (modeled) · no federal credit
Typical result:
- About 19 panels (400 W)
- 7.3 kW at 4.5 sun hours
- $22,000 before incentives
- About 16.3-year simple payback
25 years without solar vs with solar
Scenario: a $150/month electric bill at the U.S. average rate. 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
Without solar
25-year utility bills
$65,600
Rates rise ~3% per year
With solar
System cost + remaining bills
$41,600
Installed cost, no federal credit
Difference
Estimated 25-year net
+$24,000
Before any state or utility incentives
How Many kWh Does a $150 Electric Bill Represent?
Divide your monthly bill by your utility’s price per kWh. The EIA reports a U.S. average residential rate of 18.19¢/kWh (July 2026 year-to-date). At that rate, $150 buys about 825 kWh a month ($150 ÷ the rate in dollars), or roughly 9,896 kWh a year.
Rates differ widely by state, so the same $150 covers very different amounts of electricity:
| State | Avg residential rate (July 2026 YTD) | kWh per $150 |
|---|---|---|
| North Dakota | 12.36¢ | 1,214 |
| Texas | 16.06¢ | 934 |
| U.S. average | 18.19¢ | 825 |
| Massachusetts | 30.14¢ | 498 |
| California | 33.25¢ | 451 |
| Hawaii | 46.28¢ | 324 |
Rates: EIA Electric Power Monthly, Table 5.6.B, July 2026 year-to-date. kWh = 150 ÷ rate. Your bill also includes fixed charges and taxes, so your real kWh use may be somewhat higher than this estimate. Check the kWh figure printed on your own bill.
Chart summary: The same $150 buys more than three times as much electricity in North Dakota (about 1,214 kWh) as in Hawaii (about 324 kWh). A high rate means a small kWh load, so a $150 bill in an expensive state needs a smaller solar system than the same bill in a cheap-power state.
Run the numbers for your state
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How Many Solar Panels Do You Need for $150 a Month?
Solar is sized to annual kWh use, not to dollars. The formula is:
System size (kW DC) = Annual kWh ÷ (Peak sun hours × 365 × 0.82) 9,896 ÷ (4.5 × 365 × 0.82) = 7.30 kW, or 19 panels at 400 W
The 0.82 factor is this site’s standard allowance for inverter, wiring, soiling and temperature losses (a 82% overall efficiency factor). Peak sun hours are the daily average of full-strength sunshine on the panels, and they vary by location. Here is the same $150 bill, about 825 kWh a month, sized at different sun-hour levels:
| Peak sun hours | System size (kW) | Cost at $3.00/W |
|---|---|---|
| 3.5 | 9.4 | ≈$28,300 |
| 4.0 | 8.3 | ≈$24,800 |
| 4.5 (U.S. average) | 7.3 | ≈$22,000 |
| 5.0 | 6.6 | ≈$19,800 |
| 5.5 | 6.0 | ≈$18,000 |
| 6.0 | 5.5 | ≈$16,500 |
Calculated, not measured: 825 kWh/month demand, 82% system efficiency, $3.00/W. Divide kW by 0.4 for an approximate count of 400 W panels; the range across 4.0 to 6.0 sun hours is 14 to 21 panels. Look up your location’s sun hours and a precise production estimate in NREL’s PVWatts calculator. For more on this topic, see our guide to How Many Solar Panels for a $75 Electric Bill?.
Chart summary: The required array falls steadily as sunshine increases, from about 9.4 kW at 3.5 sun hours to about 5.5 kW at 6.0. That is why the answer to “how many panels” is a range (14 to 21 at 4.0 to 6.0 sun hours) rather than a single number. A cloudy-climate home needs far more panels than a desert home to cover the same load.
If the required system is larger than your roof can hold, cutting usage first (efficient lighting, a smart thermostat, heat-pump upgrades) shrinks the system you need.
What Does a Solar System for a $150 Bill Cost in 2026?
For the 4.5-sun-hour baseline, a 7.3 kW system costs about $22,000 at this site’s $3.00 per watt blended model price. Sources disagree on price because they measure different things: EnergySage marketplace quotes have averaged lower, about $2.60 per watt in 2026, while full-market installer quotes run higher. Applied to the same system:
| Price basis | $/watt | System cost |
|---|---|---|
| This site’s model price | $3.00 | $22,000 |
| EnergySage marketplace average (2026) | $2.60 | $19,100 |
Cost = system watts × $/W. Larger systems usually cost less per watt, and prices vary by state and installer.
The federal credit is gone for purchases. The One Big Beautiful Bill Act ended the Residential Clean Energy Credit (IRC Section 25D) for expenditures after December 31, 2025. The IRS says it cannot be claimed for property installed after that date, even if you paid before then. Third-party-owned systems (leases and PPAs) may still benefit from the commercial credit under Section 48E, so ask any provider how savings are passed through to you. Some states, utilities and local programs still offer incentives, so check the DSIRE database and verify current terms before you decide. This is not tax advice; confirm with a tax professional.
How Long Until Solar Pays for Itself on a $150 Bill?
Our baseline model puts simple payback near 16.3 years. Assumptions: a 7.3 kW system at $22,000, a residential price of 18.19¢/kWh (EIA national average, July 2026), 75% of the bill offset in year 1 to account for fixed charges and export credit rules, 3% yearly rate increases, and 0.5% yearly panel degradation. Year-1 savings come to about $1,350, a simple payback of about 16.3 years, or about 13.9 years once rising rates are counted. To see how your state compares, our guide to Solar Panel Payback Period by State has the full data.
How much of the bill solar removes depends on how your utility credits exports. This site’s model uses these bill-offset levels by net-metering type:
| How exports are credited | Bill offset | Year-1 savings | Simple payback |
|---|---|---|---|
| Full retail net metering | 87% | $1,566 | 14.0 years |
| National blended average (baseline) | 75% | $1,350 | 16.3 years |
| Reduced / net billing | 70% | $1,260 | 17.5 years |
| Low export credit (California NEM 3.0, Hawaii) | 60% | $1,080 | 20.4 years |
| Limited or no statewide net metering | 55% | $990 | 22.2 years |
Payback = system cost ÷ year-1 savings at the national average rate, with no incentives and no financing costs. The offset levels are this site’s modeling categories, not published utility rates. Use your own utility’s rules in the solar payback calculator.
Chart summary: At the model price the system breaks even after about 13.9 years once rate increases are counted, and at $2.60/W it breaks even after about 12.3 years. A utility that pays less than retail for exports pushes both lines to the right, so get a utility-specific estimate and consider whether a battery that raises self-use is worth pricing, especially under California NEM 3.0.
Over 25 years the model puts utility bills at about $65,600 without solar. The solar side (installed cost plus remaining bills) comes to about $41,600, leaving a modeled net gain of roughly $24,000. Lower rates, weak export credits and financing costs would reduce that figure.
Solar vs utility company · 25-year comparison
25-year totals for a $150/month electric bill at the U.S. average rate: 3%/yr rate increases, 0.5%/yr degradation, no federal credit. Methodology
Total utility payments
$65,600
Total solar cost (installed + remaining bills)
$41,600
Net savings
+$24,000
Avg. monthly difference
+$113/mo
Will the System Fit Your Roof?
A 400 W panel typically covers roughly 18–22 square feet, so 19 panels need about 342–418 square feet of clear, unshaded roof. South-facing roofs produce the most in the continental U.S. East- and west-facing roofs typically give up some output (often in the 10–20% range), and north-facing roofs are usually a poor fit. Run your roof’s exact tilt and direction through PVWatts rather than relying on rules of thumb.
Shade usually matters more than orientation. A shaded section of a string-wired array can drag down the whole string, so microinverters or DC optimizers are worth pricing if trees or chimneys cast shadows. If roof space is tight, higher-wattage panels (for example 440 W) cut the panel count: about 17 instead of 19 for the 7.3 kW example. Satellite tools such as Google Project Sunroof can give a first look at your roof before you call installers.
Before you request quotes, run your numbers in our solar savings calculator and system size calculator, and compare at least three installer quotes.
Sources: EIA Electric Power Monthly, Table 5.6.B (July 2026 year-to-date residential prices); SEIA, “Clean Energy Provisions in the One Big Beautiful Bill”; IRS, Residential Clean Energy Credit; EnergySage cost data (2026); NREL PVWatts; DSIRE. Model assumptions are on the methodology page.
Frequently asked questions
Direct answers for US homeowners.
Popular state solar guides
Electricity rates and incentives vary — see data for your state.
How these numbers were calculated
- Electricity rate
- 18.19¢/kWh — US 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
- 4.5 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
- National blend — solar assumed to offset 75% of the bill (87% in full-retail net-metering states, 55–70% elsewhere).
- Model
- Version 2026.10 · 3%/yr electricity price escalation · 0.5%/yr panel degradation · simple payback = installed cost ÷ year-1 savings
- Policy checked
- · Full methodology · Report an error
Estimates only — not tax, legal or financial advice. Get at least three installer quotes and confirm incentives with your utility and a tax professional.