US residential solar · 2026 data

Solar Panels for a 2,800 sq ft House

Q: What size solar system do I need for a 2,800 sq ft house?

Divide your annual kWh by your location's yield in kWh per kW per year, then divide by 0.4 kW per panel and round up. A home using 12,000 kWh a year needs about 6.8 kW near Phoenix and 9.3 kW in Columbus, based on PVWatts-derived yields. Run NREL's free PVWatts on your address to confirm.

Q: How much does solar cost for a 2,800 sq ft house in 2026, and is there a federal tax credit?

Expect roughly $2.50–$3.50 per watt installed: about $20,000–$28,000 for 8 kW and $30,000–$42,000 for 12 kW. The 30% federal Residential Clean Energy Credit (Section 25D) does not apply to expenditures made after December 31, 2025, so check state, local and utility incentives in the DSIRE database.

Q: How long does solar payback take for a large home in 2026?

In this guide's model (8.1 kW at $3.00/W, no federal credit, 100% offset), simple payback is about 11.7 years at the 2025 U.S. average of roughly 17.3¢/kWh, about 6.8 years at 30¢, and about 16.9 years at 12¢. Net-metering rules, financing costs and inverter replacement can shift these figures.

Q: Is solar still worth it for a 2,800 sq ft house without the federal credit?

Often, where electricity rates are high or rising, the roof is unshaded and you will stay 10+ years. The reference system here nets about $24,500 over 25 years at a flat 17.3¢/kWh. It is weaker with low rates, heavy shade or poor export credits. Compare at least three quotes against a PVWatts estimate.

Est. net savings

$24,500

Over 25 Years (modeled, flat rates) · no federal credit

$24,400 Gross cost (ref. system)

11.7 yrs Modeled payback

8.1 kW Reference system

Typical result:

18–31 panels (400 W)
8.1 kW reference system
$24,400 gross cost, no federal credit
11.7 year modeled payback

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

Updated September 30, 2026 · 9 min read ·By Green Energy Calculators Editorial Team

Calculate My System Size View State Data

25 years without solar vs with solar

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

$48,900

Rates rise ~3% per year

With solar

System cost + remaining bills

$24,400

Installed cost, no federal credit

Difference

Estimated 25-year net

+$24,500

Before any state or utility incentives

Author Green Energy Calculators Editorial Team

Editorial policy No paid placements

Last updated Sep 30, 2026

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

A 2,800 sq ft house typically needs 18 to 31 solar panels (400 W each), a system of roughly 7–12.5 kW, to offset 100% of its electricity at 1,000–1,300 kWh per month. The exact number depends on how much electricity you use and how much sun your roof gets, not on square footage alone. Installed cost is commonly $2.50–$3.50 per watt, and as of 2026 there is no 30% federal tax credit for homeowner-purchased systems (Section 25D ended after December 31, 2025).

Quick facts (reviewed September 30, 2026):

Panels: 18–31 at 400 W each, for the 1,000–1,300 kWh/month scenarios used in this guide
System size: about 7–12.5 kW
Cost before incentives: about $20,000–$28,000 for 8 kW; $30,000–$42,000 for 12 kW
Federal credit: ended for homeowner-purchased systems with expenditures after December 31, 2025
Modeled payback: about 7–17 years, mostly depending on your electricity rate

How Many Solar Panels Does a 2,800 sq ft House Need?

Start with your own electricity use, not the size of your house. The U.S. Energy Information Administration (EIA) reports that the average U.S. residential customer used about 861 kWh per month in 2023. Larger homes, electric heating, EVs and pools push usage higher, so this guide uses two planning scenarios for a 2,800 sq ft home: 1,000 and 1,300 kWh per month. These are assumptions, not averages. Replace them with the 12-month average from your utility bills.

The sizing formula is simple:

System size (kW) = annual kWh ÷ local yield (kWh produced per kW of panels per year)

Panels = system size (kW) ÷ 0.4 kW per 400 W panel, rounded up

The yield figures below come from NREL’s PVWatts model, which already includes its default system losses (inverter, wiring, temperature, soiling). Worked example: a Houston-area home using 1,000 kWh/month uses 12,000 kWh a year. At a yield of about 1,476 kWh per kW, it needs 12,000 ÷ 1,476 = 8.1 kW, or 21 panels.

Monthly use	Annual use	System size (Houston-type yield)	Panels (400 W)
800 kWh	9,600 kWh	6.5 kW	17
1,000 kWh	12,000 kWh	8.1 kW	21
1,300 kWh	15,600 kWh	10.6 kW	27
1,600 kWh	19,200 kWh	13.0 kW	33

Usage is the biggest swing factor: the same house can need half as many panels if you use half as much electricity. Use our solar system size calculator to enter your own bills and ZIP code.

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 a 2,800 sq ft House Cost in 2026?

Published 2026 pricing for residential solar generally falls between $2.50 and $3.50 per watt installed, before incentives. Marketplace data (such as EnergySage) tends to sit at the lower end, while industry benchmark reports (SEIA/Wood Mackenzie) sit higher, and prices vary by state, roof complexity and equipment. Applied to the system sizes in this guide:

System size	Panels (400 W)	Gross cost at $2.50/W	Gross cost at $3.50/W
8 kW	20	$20,000	$28,000
10 kW	25	$25,000	$35,000
12 kW	30	$30,000	$42,000

Installed cost before incentives. A 10 kW system runs about $25,000 to $35,000 at $2.50 to $3.50 per watt. Source: author calculation using the commonly reported 2026 U.S. residential price range (EnergySage, SEIA/Wood Mackenzie).

Chart summary: Cost scales with system size and price per watt. The gap between a low and a high quote on the same 10 kW system is about $10,000, which is why comparing several installers matters as much as choosing the panel count.

Incentives have changed. The One Big Beautiful Bill Act ended the 30% Residential Clean Energy Credit (Section 25D) for expenditures made after December 31, 2025, according to the IRS FAQ on the law. If installation is completed after that date, the expenditure counts as made after it. Guides that still advertise a 30% credit “through 2032” are out of date. What may still help:

State, local and utility incentives. These vary widely and change often. Search your state in the DSIRE database and confirm current terms with the program itself.
Net metering or export credits. How your utility pays for excess solar power can change payback more than the sticker price. Some markets, including California, have moved to lower export rates in recent years.
Leases and power purchase agreements. These are financed by the provider under a separate commercial credit (Section 48E) that remains available on a limited timeline. Ask any provider how it affects your price, and read the contract terms carefully.

For tax questions specific to your situation, consult a qualified tax professional. This guide is informational and is not tax, legal or financial advice.

Solar vs utility company · 25-year comparison

25-year totals: 3%/yr rate increases, 0.5%/yr degradation, no federal credit. Methodology

Total utility payments

$48,900

Total solar cost (installed + remaining bills)

$24,400

Net savings

+$24,500

Avg. monthly difference

+$82/mo

See my savings →

How Do Location and Peak Sun Hours Change the Panel Count?

Peak sun hours are the equivalent hours per day of full-strength sunlight your roof receives. More sun means fewer panels for the same electricity use. The table applies the formula above to five U.S. cities, using PVWatts-based yields for a fixed, south-facing roof mount at a 20° tilt. For more on this topic, see our guide to How Many Solar Panels for a 5,000 sq ft House?.

City	Peak sun hours/day	Yield (kWh per kW per year)	1,000 kWh/mo: kW / panels	1,300 kWh/mo: kW / panels
Phoenix, AZ	6.52	1,753	6.8 kW / 18	8.9 kW / 23
San Jose, CA	5.86	1,667	7.2 kW / 18	9.4 kW / 24
Houston, TX	5.33	1,476	8.1 kW / 21	10.6 kW / 27
Boston, MA	4.72	1,339	9.0 kW / 23	11.7 kW / 30
Columbus, OH	4.57	1,296	9.3 kW / 24	12.0 kW / 31

400 W panels needed by city. A Phoenix home needs about 18 panels at 1,000 kWh/month versus about 24 in Columbus. Source: author calculation from NREL PVWatts-based yields (fixed roof mount, 20° tilt, south-facing).

Chart summary: At 1,000 kWh/month, a Phoenix home needs about 18 panels and a Columbus home about 24. That is roughly a third more panels for the same electricity use. At 1,300 kWh/month the range is 23 to 31 panels. This is where the 18–31 range in this guide comes from.

Your roof matters as much as your city. South-facing roofs generally produce the most in the continental U.S., while east- or west-facing and shaded roofs produce less and may need more panels, or higher-wattage panels if roof space is limited. Use the solar output calculator or NREL’s PVWatts tool to model your exact roof. Yields here are a typical-year approximation, so treat the results as a starting point for installer quotes.

How Long Does Solar Payback Take for a Large Home?

Simple payback is the system’s cost divided by its annual electricity savings. The biggest input is your electricity rate. EIA data put the U.S. residential average at roughly 17.3¢ per kWh in 2025, and rates were above 18¢ by spring 2026, with much higher prices in states such as California and New York.

The model below uses a reference home: 12,000 kWh per year (1,000 kWh/month), a Houston-type yield, an 8.1 kW system at $3.00 per watt (about $24,400), 100% of the bill offset at the full retail rate, and no federal credit. It ignores rate increases, financing costs and equipment replacement.

Modeled payback vs. electricity rate. Payback falls from about 16.9 years at 12¢/kWh to about 6.8 years at 30¢/kWh, with no federal credit. Source: author calculation; U.S. average rate from EIA.

Chart summary: Payback falls from about 16.9 years at 12¢/kWh to 11.7 years at the 2025 national average of 17.3¢, and to about 6.8 years at 30¢/kWh. Rates above 25¢ shorten payback the most, but only if your utility credits solar exports at or near retail rates. In places with lower export credits, payback is longer than this chart shows.

Financing changes cash flow, not the payback math. As an illustration, a $30,000 loan at 6.99% over 20 years costs about $232 per month, so compare that payment with your current electric bill. Our solar payback calculator models cash and loan scenarios side by side.

Is Solar Worth It for a 2,800 sq ft House in 2026?

For the reference system above, the 25-year value of the electricity produced is about $48,900 (12,000 kWh in year one, declining 0.5% per year, valued at a flat 17.3¢), against a cost of about $24,400. That is roughly $24,500 in modeled net savings. NREL research puts median panel degradation at about 0.5% per year. The figure does not include a possible inverter replacement, financing interest or future rate increases, so real results can land above or below it.

Solar tends to make the most sense when:

You own the home and expect to stay 10 years or more.
Your roof is unshaded and faces roughly south (or has good west/east exposure).
Your electricity rate is high or rising, and your utility pays fairly for exported power.
You can get competitive quotes near the lower end of the $2.50–$3.50 per watt range.

It is a weaker fit if your rates are low, your roof is shaded, your utility pays little for exports, or you plan to sell soon. On resale, a Lawrence Berkeley National Laboratory study of about 22,000 sales in eight states (1999–2013) found buyers paid about $4 per watt more for homes with owned solar. The study is dated and covers smaller systems, so treat the premium as a rough indicator and ask a local appraiser about your market.

Before you sign, get at least three installer quotes and compare each production estimate against PVWatts. Then use our solar savings calculator to check your own 25-year numbers.

Methodology and Sources

All panel counts and payback figures are author calculations from the inputs below. Round numbers in the text are rounded from these calculations. Last reviewed September 30, 2026.

Panel rating: 400 W per panel, rounded up to whole panels.
City yields and peak sun hours: PVWatts-based values for a fixed, south-facing roof mount at a 20° tilt, as compiled by SunWatts. Your address will differ, so run NREL PVWatts for a site-specific estimate.
Electricity use: EIA, Today in Energy (861 kWh per month in 2023). The 1,000 and 1,300 kWh/month scenarios are planning assumptions.
Electricity prices: EIA Electric Power Monthly (about 17.3¢/kWh residential average in 2025).
Installed cost: $2.50–$3.50 per watt, the commonly reported 2026 residential range across EnergySage marketplace data and SEIA/Wood Mackenzie benchmarks.
Federal credit status: IRS FAQ on Public Law 119-21.
State incentives: DSIRE.
Home value premium: Lawrence Berkeley National Laboratory (2015).
Degradation: NREL median of about 0.5% per year.

Frequently asked questions

Direct answers for US homeowners — sized for a $200/month electric bill.

How many solar panels does a 2,800 sq ft house need?

Most need about 18 to 31 panels (400 W each), or roughly 7–12.5 kW, to offset 1,000–1,300 kWh of monthly use. A home using 1,000 kWh/month needs about 18 panels near Phoenix and about 24 in Columbus, Ohio. Your electricity bills and local sun hours set the count, not square footage itself.

What size solar system do I need for a 2,800 sq ft house?

How much does solar cost for a 2,800 sq ft house in 2026, and is there a federal tax credit?

How long does solar payback take for a large home in 2026?

Is solar still worth it for a 2,800 sq ft house without the federal credit?

Same usage, bill-based guide

Your 2,800 sq ft House target maps to roughly a $200/month electric bill nationally.

$200 $200/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.