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 home using 1,750 kWh per month uses about twice the typical U.S. household, which the U.S. Energy Information Administration (EIA) puts at roughly 865 kWh per month for 2024. That level is common in large homes with electric heating or cooling, pool pumps, or EV charging. At the U.S. average of about 5 peak sun hours per day, you need a 14.6 kW system, or about 37 panels at 400W. Depending on your city the range is roughly 28 to 47 panels. In 2026, the cost picture also changed: the 30% federal homeowner tax credit ended on December 31, 2025, so payback now depends mostly on your electricity rate and state incentives.
Quick answer: About 37 panels (14.6 kW) · about $40,900 at $2.80/W · 11–13 years payback at the 17.3¢/kWh U.S. average · no federal homeowner credit for systems placed in service after 2025.
⚡ System Size
How Many Solar Panels Do You Need for 1,750 kWh per Month?
Start with daily demand: 1,750 kWh ÷ 30 days = 58.3 kWh per day. Divide by your location’s peak sun hours, apply an 80% system efficiency factor (a conservative allowance for inverter, wiring, temperature, and soiling losses), then divide by panel wattage.
System size (kW) = Daily kWh ÷ (Peak Sun Hours × 0.80)
NREL’s PVWatts Calculator models peak sun hours by address. The U.S. average is about 5 peak sun hours per day; Phoenix is near the top of the range at about 6.5, while Seattle is near 4. Plugging representative values into the formula gives:
Solar System Size by Location — 1,750 kWh/Month (400W panels)
Location
Peak Sun Hours/Day*
Required System Size
Panels (400W)
Phoenix, AZ
6.5
11.2 kW
28
Houston, TX
5.3
13.8 kW
35
U.S. average
5.0
14.6 kW
37
Atlanta, GA
4.7
15.5 kW
39
Chicago, IL
4.5
16.2 kW
41
Seattle, WA
3.95
18.5 kW
47
*Approximate annual-average values rounded from NREL PVWatts/NSRDB-based sources. Your roof’s tilt, direction, and shade change the result, so model your own address in PVWatts before buying.
Data visualization
Required system size for 1,750 kWh/month by city (kW). Phoenix needs about 11.2 kW versus 18.5 kW in Seattle; the orange bar is the U.S. average of 14.6 kW. Source: NREL PVWatts-based peak sun hours; author calculation at 80% efficiency.
Chart summary: The same 1,750 kWh/month needs about 11 kW in Phoenix but about 18.5 kW in Seattle, so sun hours alone change the required system by roughly 40%. A homeowner in the Southwest can offset this usage with about 28 panels; a Pacific Northwest home needs about 47. This is why a ZIP-code-level estimate beats any national average.
A typical 400W panel covers about 20 square feet, so a 14.6 kW system needs roughly 750 square feet of unshaded roof. For a panel count tied to your address, use our solar system size calculator.
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⚡ System Size
What Does a 1,750 kWh/Month Solar System Cost in 2026?
Published 2026 averages for installed residential solar vary by source and system size, from about $2.50 to $3.30 per watt before incentives. Marketplace quote data tends to land near the low end; broader installed-price surveys sit higher. Larger systems usually cost less per watt, so a 14.6 kW system often lands below small-system averages. We use $2.80 per watt as a midpoint.
Estimated Cost of a 14.6 kW System (before state or local incentives)
Price per Watt
Gross Cost
Federal Homeowner Credit
Estimated Net Cost
$2.50 (low)
$36,500
$0
$36,500
$2.80 (midpoint)
$40,900
$0
$40,900
$3.30 (high)
$48,200
$0
$48,200
The federal credit has changed. The One Big Beautiful Bill Act, signed July 4, 2025, ended the 30% Residential Clean Energy Credit (Section 25D) for property placed in service after December 31, 2025. Many older guides, including earlier versions of this one, still show a 30% credit through 2032; that no longer applies to a homeowner-owned system installed in 2026. Third-party-owned systems (leases and power purchase agreements) may still qualify for a commercial credit under Section 48E, subject to deadlines, so ask any provider to explain exactly what they claim and what they pass on. This is not tax advice; confirm with a tax professional.
The $11,700 gap between the low and high price points is the main reason to compare at least three quotes on a dollars-per-watt basis. With no federal credit to soften the difference, confirm what equipment, labor, permits, and warranties each quote includes.
Solar vs utility company · 25-year comparison
25-year totals: 3%/yr rate increases, 0.5%/yr degradation, no federal credit. Methodology
How Long Does Solar Take to Pay Off at 1,750 kWh/Month?
At the 2025 U.S. average residential electricity price of about 17.3 cents per kWh (EIA), your 1,750 kWh/month costs about $303 per month, or $3,630 per year. A 14.6 kW system that offsets about 90% of that value saves roughly $3,270 in year one. The 90% allowance covers fixed utility charges and export credits worth less than retail.
Assumptions: $40,900 cost; 17.3¢/kWh; 90% of usage offset; 0.5% annual panel degradation; no incentives, financing, maintenance, or inverter replacement; undiscounted dollars.
Flat electricity rates: payback in about 12.9 years, and about $36,100 net savings over 25 years.
Rates rising 3% per year (an assumption, not a forecast): payback in about 11.0 years, and about $70,600 net savings over 25 years.
Data visualization
Cumulative net cash flow for a 14.6 kW system ($). Flat rates reach about +$36,100 by year 25 versus about +$70,600 with an assumed 3% yearly rate increase. Source: EIA 2025 average of 17.3¢/kWh; author calculation, no federal credit.
Chart summary: Under flat rates the system breaks even between years 12 and 13 and is about $36,000 ahead after 25 years. If rates rise 3% per year, break-even moves to about year 11 and the 25-year gain roughly doubles. Real results depend on your utility’s rate changes, so treat both lines as scenarios, not predictions.
Your electricity rate is the biggest lever. The chart below holds everything else constant.
Data visualization
Simple payback (years) for a $40,900 system by electricity price. At the 17.3¢/kWh U.S. average the system pays back in about 12.9 years with flat rates. Source: EIA residential prices; author calculation, no federal credit.
Chart summary: At about 12¢/kWh, payback stretches to roughly 15 to 19 years, near the end of a typical 25-year panel warranty. At about 28¢/kWh, similar to the 2023 averages EIA reported for Connecticut and Massachusetts (roughly 30¢), it drops to about 7 to 8 years. Check your own rate on a recent bill before relying on any national average.
Batteries add roughly $8,000 to $15,000 and rarely pay for themselves on savings alone. They make the most sense where exports earn far less than retail or where backup power has value to you.
🌎 State Comparison
State Incentives and Net Metering for High-Usage Homes
With the federal homeowner credit gone, state and utility programs carry more weight. Rules change often, so verify each program before you sign. A few verified examples:
Selected State Incentives (verify current terms)
State
Incentive
Notes
New York
State income tax credit: 25% of system cost, capped at $5,000
Nonrefundable; unused credit carries forward up to five years (NYS Tax Department)
Massachusetts
State income tax credit: 15% of cost, up to $1,000
Plus sales tax exemption on solar equipment and SMART program payments
California
No retail-rate export credit for new systems
Net Billing Tariff since April 15, 2023 credits exports at time-varying avoided-cost rates
On a $40,900 system, New York’s 25% would be about $10,200, but the credit is capped at $5,000, which is about 12% of the cost. Massachusetts’ credit is capped at $1,000, about 2.4%.
Net metering matters at this usage level. Where a utility credits exports near the retail rate, you can size slightly above your annual use to bank summer surplus. Where exports earn much less, as under California’s Net Billing Tariff, oversizing pays poorly. Size to your annual consumption (about 21,000 kWh per year) and favor daytime self-use. Check your utility’s current export policy and the DSIRE database before finalizing a size.
📋 Key Insights
Before You Get Quotes: Size to Your Annual Total
Pull your 12 most recent utility bills and add up the kWh. If you average 1,750 kWh per month but some months are far lower, sizing to your peak month over-sizes the system for part of the year. Ask each installer to base its proposal on your annual kWh and to show the assumptions behind its production estimate, including tilt, direction, shading, and the PVWatts or equivalent model used. Then compare quotes on price per watt, expected annual kWh, warranty terms, and what happens to your export credits.
Panel counts and system sizes are calculated with the formula shown above. Cost and payback figures are our own calculations from the stated assumptions, not measured results or guarantees; this guide is general information, not financial or tax advice. Last reviewed October 3, 2026.
Direct answers for US homeowners — sized for a $300/month electric bill.
About 37 panels rated 400W each (a 14.6 kW system) at the U.S. average of roughly 5 peak sun hours per day. The range is wide: about 28 panels in Phoenix, 41 in Chicago, and 47 in Seattle. The formula is daily kWh (58.3) divided by peak sun hours times 0.80 system efficiency, then divided by panel wattage.
At typical 2026 prices of $2.50 to $3.30 per watt, a 14.6 kW system costs about $36,500 to $48,200, or roughly $40,900 at $2.80 per watt. The 30% federal Residential Clean Energy Credit (Section 25D) ended for property placed in service after December 31, 2025, so a homeowner-owned system installed in 2026 generally gets no federal credit. Lease and PPA providers may still claim a commercial credit under Section 48E and can pass some savings on. Check state incentives, and ask a tax professional about your situation.
At the 2025 U.S. average residential price of about 17.3 cents per kWh, a roughly $40,900 system that offsets 90% of your usage pays back in about 12.9 years if rates stay flat, or about 11.0 years if rates rise 3% per year. Near 28 cents per kWh payback falls to about 8 years (flat) or 7 years (rising rates); near 12 cents it stretches to 15 to 19 years. These figures exclude state incentives, financing costs, and inverter replacement.
Yes. Where utilities credit exports near the retail rate, a slightly larger system can bank summer surplus for winter. Where exports earn much less than retail, as under California's Net Billing Tariff since April 2023, oversizing pays poorly, so size to your actual annual usage of about 21,000 kWh and use more of the power yourself. Net metering rules differ by state and utility, so confirm with your utility before choosing a size.
A typical 400W panel covers roughly 20 square feet, so about 37 panels need around 750 square feet of unshaded roof, and 47 panels (Seattle-type sun) need around 950. Roof orientation, tilt, shade, and setbacks reduce usable area. If the roof is too small, higher-wattage panels or a ground mount can close the gap. Run your address through PVWatts or get an installer site assessment.
Same usage, bill-based guide
Your 1,750 kWh/Month target maps to roughly a $300/month electric bill nationally.
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).
Estimates only — not tax, legal or financial advice. Get at least three installer quotes and confirm incentives with your utility and a tax professional.