US residential solar · 2026 data

Solar Panels for 1,500 kWh/Month

Q: How much does a solar system for 1,500 kWh per month cost in 2026?

At this site's $3.00 per watt model price, a 13.4 kW system costs about $40,100 before incentives. Real quotes vary by installer, roof and state, so compare at least three, and ask for a line-by-line breakdown of any quote far above or below that figure.

Q: Has the 30% federal solar tax credit ended for 2026?

Not for homeowners who buy a system with cash or a loan. The One Big Beautiful Bill Act ended the Section 25D Residential Clean Energy Credit for expenses after December 31, 2025. Unused credit from a system completed by that date can carry forward. State and local incentives may still apply, and third-party-owned lease or PPA systems may still qualify for a business credit claimed by the owner, so ask your installer how it affects your payments. Check the IRS and DSIRE for current rules.

Q: How long does it take for solar to pay for itself at 1,500 kWh per month?

In our baseline model (13.4 kW, $40,100, 18.19¢/kWh) simple payback is about 16.3 years without the federal credit, or about 13.9 years once 3% yearly rate increases are counted. Payback is shorter in high-rate states such as California and New York and longer where electricity is cheap. These are modeled estimates that exclude financing costs, maintenance and inverter replacement.

Q: How do roof direction and shading change the number of panels?

Less sunlight on the array means more panels for the same output. Divide your panel count by (1 − the output loss). For example, if an east- or west-facing roof loses 15% versus an ideal south-facing one (a hypothetical figure), 34 panels become about 40. Shade can cost more than orientation. Model your exact roof in NREL's free PVWatts calculator or ask installers for a shade-adjusted production estimate.

Est. net savings

$43,600

Over 25 Years (modeled) · no federal credit

$40,100 Cost (no federal credit)

16.3 yrs Simple payback

13.4 kW System size

Typical result:

About 34 panels (400 W)
13.4 kW system at 4.5 sun hours
About $40,100 before incentives
About 16.3-year simple payback

✓ EIA rates & NREL sun data ✓ 2026 federal policy applied ✓ Open methodology

Updated October 5, 2026 · 9 min read ·By Green Energy Calculators Editorial Team

Calculate My System Size View State Data

25 years without solar vs with solar

Scenario: a home using 1,500 kWh a month. 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

$119,400

Rates rise ~3% per year

With solar

System cost + remaining bills

$75,800

Installed cost, no federal credit

Difference

Estimated 25-year net

+$43,600

Before any state or utility incentives

Author Green Energy Calculators Editorial Team

Editorial policy No paid placements

Last updated Oct 5, 2026

Data approach EIA rates · NREL sun hours · 2026 federal policy · methodology

Short answer: a home using 1,500 kWh per month needs about 34 solar panels (400 W each), a 13.4 kW system, at the US-average 4.5 peak sun hours per day. Depending on how sunny your location is, that ranges from about 25 to 38 panels. In 2026 such a system costs roughly $40,100 before incentives at this site’s $3.00-per-watt model price, because the 30% federal homeowner tax credit ended on December 31, 2025.

Last updated October 6, 2026. Prices, rates and incentive rules change; see Methodology and Sources.

Three variables do most of the work: your local peak sun hours, the wattage of the panels you choose, and how your roof faces and is shaded. A home in Phoenix with a south-facing roof needs far fewer panels than one in the Pacific Northwest, where winter sun is weak.

This guide shows the sizing formula step by step, a worked example for a high-sun location, honest 2026 costs and payback without the federal credit, and how your state’s electricity rate changes the answer.

Reading from outside the US? The sizing formula below works anywhere: use your own local peak sun hours and your own tariff. The cost, incentive and rate figures in this guide are for the United States in US dollars.

How Many Solar Panels Do You Need for 1,500 kWh per Month?

1,500 kWh per month is about 49 kWh per day (1,500 × 12 ÷ 365). Divide that by your local peak sun hours and the site’s standard efficiency factor of 0.82 (a 82% overall factor covering inverter, wiring, temperature and soiling losses):

System size (kW) = Daily kWh ÷ (Peak Sun Hours × 0.82)

At the US average of 4.5 peak sun hours: 49 ÷ (4.5 × 0.82) = 13.4 kW. Divide by the panel wattage: 13,400 W ÷ 400 W = about 34 panels. With 450 W panels you need about 30.

Solar system size for 1,500 kWh/month by sun hours (representative states, 100% offset)

State	Peak sun hours (state average)	System size	Panels (400 W)
Arizona	6.5	9.3 kW	24
Florida	5.7	10.6 kW	27
North Carolina	5.2	11.6 kW	29
Ohio	4.3	14.0 kW	35
Washington	4.0	15.0 kW	38

Sun hours are approximate state averages based on NREL solar resource data. Enter your address in NREL PVWatts for a site-specific figure, or use our solar system size calculator.

Panel brand matters less than sun, tilt and shade. A higher-wattage panel reduces the panel count and roof area you need, but the kilowatt size of the system is set by your energy use and sun hours. Your usage also changes over time (EVs, heat pumps), so some installers size above current use.

What changes the panel count

Roof direction and tilt: less output per panel means more panels. Panels needed = base count ÷ (1 − output loss).
Shade: trees or nearby roofs can cost more than orientation does; microinverters or optimizers reduce the impact.
Net metering rules: your utility may cap system size or pay less for exported power, which affects how large a system makes sense.
Panel wattage: 450 W panels need about 30 panels instead of 34 for the same 13.4 kW.

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.

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What Does a Solar System for 1,500 kWh/Month Cost in 2026?

This site’s model uses $3.00 per watt installed before incentives. For the 13.4 kW system above, that is about $40,100. Individual quotes vary: EnergySage marketplace reports put average quotes near $2.60 per watt in 2026 (about $34,800 for this system), while full-market installer quotes run higher.

Panels are only about 12% of the total cost, according to EnergySage; inverters, labor, permits, racking, and installer overhead make up the rest. Because installer pricing varies widely, getting at least three quotes is one of the most effective ways to lower the price. For more on this topic, see our guide to How Many Solar Panels for 400 kWh/Month?.

The federal tax credit has changed. The 30% Residential Clean Energy Credit (Section 25D) ended for expenses after December 31, 2025, under the One Big Beautiful Bill Act (Public Law 119-21). A homeowner who buys a system with cash or a loan in 2026 cannot claim it. The IRS lists the rules on its Residential Clean Energy Credit page. Lease and PPA systems are owned by a company that may still claim a business credit (Section 48E, subject to deadlines); whether that lowers your monthly payment depends on the provider. Check state and local programs in DSIRE, which tracks state incentives.

Estimated installed cost of a 1,500 kWh/month system by state sun hours, before incentives (2026). Calculated as system size at each state’s average sun hours × $3.00 per watt. Actual quotes vary by installer.

Chart summary: The same 1,500 kWh/month of usage costs about $27,800 to install in Arizona but about $45,100 in Washington, because lower sun hours require a system roughly 1.6 times larger. These are calculated estimates at $3.00 per watt, not installer quotes.

For financing, our solar loan calculator compares a monthly payment with your current utility bill.

Solar vs utility company · 25-year comparison

25-year totals for a home using 1,500 kWh a month: 3%/yr rate increases, 0.5%/yr degradation, no federal credit. Methodology

Total utility payments

$119,400

Total solar cost (installed + remaining bills)

$75,800

Net savings

+$43,600

Avg. monthly difference

+$205/mo

See my savings →

Worked Example: A 10 kW System in a High-Sun Location

This is an illustrative calculation, not measured production data. Assume a south-facing roof in a high-sun location such as Phoenix, AZ, using Arizona’s state-average 6.5 peak sun hours per day:

Input	Value
System size	10 kW (25 panels × 400 W)
Peak sun hours (state average)	6.5 per day
Efficiency factor	0.82
Annual production	10 kW × 6.5 × 365 × 0.82 = about 19,455 kWh
Annual use at 1,500 kWh/month	18,000 kWh
Share of use covered	about 108%

Real output varies by month: it peaks in spring and summer and dips in December and January. Whether your utility credits surplus production at retail rates or lower rates changes the dollar value. For a site-specific estimate, run your address through NREL PVWatts.

Panels lose output slowly as they age. NREL research has found a median degradation rate of about 0.5% per year; the payback model below uses 0.5% per year (about 88% of original output after 25 years).

Resale value: a 2015 study by Lawrence Berkeley National Laboratory, Selling Into the Sun, found buyers paid a premium of about $4 per watt for owned systems, equal to about $15,000 for an average 3.6 kW system. The data is a decade old and covers much smaller systems than 13.4 kW, so do not multiply it out for a large array. Leased systems generally do not show the same premium.

How Long Does Payback Take Without the Federal Tax Credit?

At the US average residential rate of about 18.19¢ per kWh (EIA, July 2026), 1,500 kWh costs about $273 per month, or $3,276 per year. A system that offsets 75% of it (allowing for fixed charges and export credit rules) saves about $2,456 in year one. Against a $40,100 system with no federal credit, the baseline model gives:

Simple payback: about 16.3 years
Once 3% yearly rate increases are counted: about 13.9 years

Both include 0.5% annual panel degradation. They ignore financing interest, maintenance, inverter replacement (typically once in a system’s life) and any state incentives. The 3% rate growth is an assumption, not a forecast.

Modeled cumulative net cash flow for a 13.4 kW system that offsets 1,500 kWh/month, no federal credit. Breaks even after about 13.9 years and reaches about $43,600 by year 25 on a $40,100 cost. Source: EIA residential price of 18.19 cents per kWh (July 2026); Green Energy Calculators model with 3% yearly rate growth.

Chart summary: In this model the system breaks even after about 13.9 years and ends year 25 about $43,600 ahead, assuming a $40,100 cost, 75% of the bill offset, 3% yearly rate growth, and 0.5% yearly panel degradation. Higher rates pull break-even closer, while low rates or weak export credits push it later.

Use the solar payback calculator to enter your own rate, quote and sun hours.

Is Solar Worth It in Your State? Electricity Rates Decide

For a fixed 1,500 kWh per month, the dollars you avoid depend mostly on your local electricity rate. The table multiplies 18,000 kWh per year by each state’s average residential rate from the EIA Electric Power Monthly (Table 5.6.B, July 2026). It shows the annual bill a system can offset, not payback, because system size and price also vary by state.

State	Avg residential rate (¢/kWh)	Annual cost of 18,000 kWh
Nevada	13.53	about $2,440
Florida	15.30	about $2,750
Arizona	15.44	about $2,780
Texas	16.06	about $2,890
Colorado	16.72	about $3,010
US average	18.19	about $3,270
Massachusetts	30.14	about $5,430
New York	29.38	about $5,290
California	33.25	about $5,990
Hawaii	46.28	about $8,330

Rates are EIA residential averages, July 2026. Check your own utility bill, since rates vary within states.

Annual cost of 1,500 kWh/month at each state’s average residential rate (EIA, July 2026). Calculated as 18,000 kWh × rate.

Chart summary: The same 1,500 kWh/month costs about $2,440 per year in Nevada and $5,990 in California, which is about 2.5 times as much. Higher rates mean each kilowatt-hour a system produces saves more, so payback is generally faster in high-rate states such as California, New York and Massachusetts, and slower in low-rate states.

Net metering matters. How your utility credits exported power can move payback by years. California, for example, moved to a net billing structure in 2023 with lower credits for exported solar. Rules differ by state and utility, so check the current tariff and DSIRE before relying on any estimate. Use the solar savings calculator for your ZIP code.

Methodology and Sources

Sizing: system kW = annual kWh ÷ (peak sun hours × 365 × 0.82); 1,500 kWh × 12 ÷ 365 ≈ 49 kWh/day. State sun hours are approximate averages based on NREL solar resource data; use site-specific modeling for real decisions.
Cost: this site’s standard model uses $3.00 per watt installed, before incentives; EnergySage marketplace data reports lower average quotes (about $2.60/W in 2026), see EnergySage’s solar cost data. Costs are our calculation (kW × $/W), not quotes. See the methodology.
Rates: US and state residential rates from the EIA Electric Power Monthly (Table 5.6.B, national July 2026, states July 2026). Savings use 18.19¢/kWh.
Payback model: 0.5% annual degradation, 75% of the bill offset in year one, and 3% annual rate growth for the “with rate increases” figure (an assumption). No financing, maintenance, inverter replacement or state incentives.
Federal credit: IRS Residential Clean Energy Credit; One Big Beautiful Bill Act (P.L. 119-21, signed July 4, 2025).
State incentives and net metering: DSIRE.
Production modeling: NREL PVWatts.
Resale premium: Lawrence Berkeley National Laboratory, Selling Into the Sun (2015).

This guide is general information, not financial, tax or installation advice. Confirm incentives and quotes with licensed installers and a tax professional.

Frequently asked questions

Direct answers for US homeowners.

How many solar panels do I need for 1,500 kWh per month?

About 34 panels of 400 W each (a 13.4 kW system) at the US-average 4.5 peak sun hours and 82% system efficiency. With 6.0 peak sun hours you need about 25 panels; with 4.0 sun hours about 38. The formula is: daily kWh ÷ (peak sun hours × 0.82) = system kW, then divide by panel wattage. For 1,500 kWh per month, daily use is about 49 kWh.

How much does a solar system for 1,500 kWh per month cost in 2026?

Has the 30% federal solar tax credit ended for 2026?

How long does it take for solar to pay for itself at 1,500 kWh per month?

How do roof direction and shading change the number of panels?

Same usage, bill-based guide

Your 1,500 kWh/Month target maps to roughly a $250/month electric bill nationally.

$250 $250/month electric bill guide Panels · cost · payback · by state →

Popular state solar guides

Electricity rates and incentives vary — see data for your state.

CA California 33.25¢/kWh · 5.8h sun TX Texas 16.06¢/kWh · 5.6h sun FL Florida 15.3¢/kWh · 5.7h sun AZ Arizona 15.44¢/kWh · 6.5h sun NC North Carolina 14.94¢/kWh · 5.2h sun NY New York 29.38¢/kWh · 4.3h sun MA Massachusetts 30.14¢/kWh · 4.2h sun CO Colorado 16.72¢/kWh · 5.5h sun

View all 50 states →

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: September 29, 2026 · 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.