How Many Solar Panels Do I Need For 1,000 kWh Per Month? (Calculator + 2026 Numbers)
To produce 1,000 kWh per month from solar, you need about 20 × 410 W panels — roughly 8 kW DC — at U.S. average sun. 1,000 kWh/month is close to the U.S. residential average of 877 kWh/month, so this is essentially "how many panels to offset an average American home." The exact panel count ranges from 15 (Phoenix) to 25 (Seattle) depending on your local peak sun hours. This guide does the math with PVWatts v8 conventions, shows the state-by-state panel count, and gives the 2026 cost picture.
I built an array on my own house in 2024 that produces about 800 kWh/month at my location. That is just under the 1,000 kWh/month target in this article — which means this article describes a system very close in size to the one sitting on my roof right now.
The Math
The formula uses NREL PVWatts v8 conventions (see How To Calculate Solar Panel Output for the full derivation):
System DC kW = (1,000 kWh/mo × 12) / (PSH × 365 × 0.83)
= 12,000 / (PSH × 302.95)
At U.S. average sun (4.98 PSH):
System kW = 12,000 / (4.98 × 302.95) = 12,000 / 1,508.7 = 7.95 kW
Panels (410 W) = 7,950 / 410 = 19.4 → 20 panels (8.20 kW)
So 20 × 410 W panels at U.S. average sun. That is the answer for a typical American homeowner. In sunnier locations you need fewer; in cloudier locations you need more.
State-By-State Panel Count For 1,000 kWh/Month
Using PVWatts v8 derate 0.83 and modern 410 W panels:
| Location | PSH | System kW | Panels (410 W) | Annual savings @ state rate |
|---|---|---|---|---|
| Phoenix, AZ | 6.54 | 6.1 | 15 | $1,680 ($0.14/kWh) |
| Las Vegas, NV | 6.41 | 6.2 | 16 | $1,560 ($0.13/kWh) |
| Albuquerque, NM | 6.42 | 6.2 | 16 | $1,680 ($0.14/kWh) |
| Los Angeles, CA | 5.61 | 7.1 | 18 | $3,600 ($0.30/kWh) |
| Denver, CO | 5.66 | 7.0 | 18 | $1,680 ($0.14/kWh) |
| Austin, TX | 5.30 | 7.5 | 19 | $1,680 ($0.14/kWh) |
| Miami, FL | 5.48 | 7.3 | 18 | $1,560 ($0.13/kWh) |
| Atlanta, GA | 5.04 | 7.9 | 20 | $1,560 ($0.13/kWh) |
| Boston, MA | 4.70 | 8.5 | 21 | $3,360 ($0.28/kWh) |
| New York, NY | 4.21 | 9.4 | 23 | $2,640 ($0.22/kWh) |
| Chicago, IL | 4.27 | 9.3 | 23 | $1,920 ($0.16/kWh) |
| Seattle, WA | 3.95 | 10.1 | 25 | $1,320 ($0.11/kWh) |
| Anchorage, AK | 3.17 | 12.5 | 31 | $2,760 ($0.23/kWh) |
The range is nearly 2:1 between Phoenix and Seattle. That is the power of sun — the same 1,000 kWh/month target takes 15 panels on an Arizona roof or 25 panels on a Washington roof.
What This System Looks Like In Practice
| Spec | Typical 8 kW system (20 × 410 W) |
|---|---|
| Panels | 20 × LONGi Hi-MO 6 410 W (HPBC) |
| DC nameplate | 8.20 kW |
| Roof area (panels only) | 420 sq ft |
| Roof area (with setbacks) | ~550 sq ft |
| Total weight (panels + BOS) | ~1,200 lbs (~2.9 psf) |
| Inverter | Enphase IQ8M microinverters (20 units) or SolarEdge SE7600H string inverter |
| Annual output at 4.98 PSH | 12,270 kWh (~1,022 kWh/month — slight oversize) |
This is a 1–1.5 day install for a two-person crew. The 20 panels need a continuous south-facing roof section of roughly 20 ft × 28 ft (or two smaller sections on a multi-plane roof).
2026 Cost And Payback
| Cost item | 8 kW system |
|---|---|
| Installed cost (LBNL median $3.10/W) | $24,800 |
| Federal 25D tax credit (2026 = $0) | $0 |
| Net cost (2026) | $24,800 |
| Same system in 2024 (with 30 % credit) | $17,360 |
| Location | Annual savings | Payback (2026) |
|---|---|---|
| Hawaii ($0.42/kWh) | $5,040 | 4.9 yr |
| California ($0.30/kWh) | $3,600 | 6.9 yr |
| Massachusetts ($0.28/kWh) | $3,360 | 7.4 yr |
| New York ($0.22/kWh) | $2,640 | 9.4 yr |
| U.S. average ($0.165/kWh) | $1,980 | 12.5 yr |
| Illinois ($0.16/kWh) | $1,920 | 12.9 yr |
| Washington ($0.11/kWh) | $1,320 | 18.8 yr |
High-rate states (HI, CA, MA) are still strong. Low-rate Pacific Northwest markets have long payback without the federal credit.
Who Should Size For 1,000 kWh/Month?
1,000 kWh/month = 12,000 kWh/year is the right target for:
- The average American household (EIA reports 877 kWh/month; 1,000 kWh/month provides a 14 % buffer)
- A ~2,000 sq ft home with gas heat, one EV, and moderate AC
- A household wanting 100 % offset including seasonal variation — the summer overproduction banks net-metering credits against winter underproduction
If you have all-electric heat, two EVs, a pool, or a large home (3,000+ sq ft), you probably need 1,500–2,500 kWh/month. See Solar Panels For 2,000 kWh Per Month or Solar Panels For 2,500 kWh Per Month.
Common Misreadings
- "30 × 300 W panels for 1,000 kWh/month." Outdated panel size. Modern answer is 20 × 410 W. Same DC capacity, 10 fewer panels, fewer mounting points, less labor.
- "The system produces exactly 1,000 kWh every month." No — production swings ±40 % by season in northern latitudes. Annual production averages 1,000 kWh/month, but December might be 550 kWh and June might be 1,350 kWh.
- "My bill is $130/month so I need 1,000 kWh/month of solar." Check your actual kWh, not dollars. If your rate is $0.16/kWh, $130 buys 812 kWh, not 1,000. If your rate is $0.30/kWh (California), $130 buys only 433 kWh.
- "I need a battery for net-metering." For grid-tie with net metering, no battery is needed — the grid is your battery. Excess daytime production credits against nighttime consumption. Batteries only make sense if your utility has poor net metering (CA NEM 3.0), TOU rates where export value is low, or if you want blackout backup.
- "The 0.75 derate factor." That was PVWatts v1 (pre-2014). Modern PVWatts v8 uses 0.83. The difference is about 10 % in panel count — older articles oversize by ~2 panels.
Bottom Line
For 1,000 kWh/month at U.S. average sun: 20 × 410 W panels (~8 kW DC), about 420 sq ft of roof, roughly $24,800 installed in 2026 (no federal credit), paying back in 5–13 years depending on your electricity rate. That is the system that offsets the average American home.
Use the calculator below for your specific location and panel wattage.
Tap to see sensitivity analysisSensitivity analysis
| Scenario | Value |
|---|---|
| Low (-20%) | 6.7 kW |
| Expected | 8.4 kW |
| High (+20%) | 10.0 kW |
PSH varies seasonally \u2014 winter values can be 30% lower. To meet your target year-round, size for the worst month, not the average.
Keep Reading
If you found this useful, these guides go deeper into related topics:
- How Many Solar Panels For 500 kWh Per Month
- How Many Solar Panels For 2,000 kWh Per Month
- How Many Solar Panels For 2,500 kWh Per Month
- How Much Power A 5 kW Solar System Produces
- How Much Power A 10 kW Solar System Produces
- How Many Panels In A 1kW–20kW Solar System
- How To Calculate Solar Panel Output
- Average Peak Sun Hours By State
- Solar Panel Calculator — Full Energy Estimate
Frequently Asked Questions
How many solar panels do I need to produce 1,000 kWh per month?
Is 1,000 kWh per month a lot of electricity?
What size solar system produces 1,000 kWh per month?
How much does a solar system for 1,000 kWh/month cost in 2026?
How much roof area do I need for 1,000 kWh per month?
How many panels for 1,000 kWh/month with 430 W panels instead of 410 W?
Can I still use the 30 % federal tax credit in 2026?
How long is the payback for a 1,000 kWh/month solar system in 2026?
Sources
- EIA — Average Monthly Residential Electricity Consumption (2024)
- NREL PVWatts v8 — Photovoltaic System Performance Calculator
- NREL National Solar Radiation Database (NSRDB)
- LBNL Tracking The Sun 2024 — Pricing And Design Trends For Distributed PV
- IRS — Section 25D Residential Clean Energy Credit (terminated 2025-12-31)
- LONGi Hi-MO 6 LR5-54HTH datasheet (2024)