How many solar panels to run an average house?
The average US home used about 863 kWh a month in 2024 (EIA). At Chicago’s PVWatts output of 1,308 kWh per kW a year, covering that takes about 7.92 kW of panels — 20 panels of 400 W.
How to work it out
- 863 kWh × 12 = 10,356 kWh a year
- ÷ 1,308 kWh per kW a year = 7.92 kW of panels
- 7,917 W ÷ 400 W = 20 panels
“A house” covers everything from a 495 kWh-a-month Hawaii home to a 1,202 kWh Louisiana one — the EIA’s state averages for 2024 span more than double. Use your own bill if you have it; this page uses the national average and a middle-of-the-country city.
Adjust for your project
More options: Offset
- Panels
- 20 panels · 400 W
- Expected output per year
- 10,464 kWh
- Average output per month
- 872 kWh
- Your use per year
- 10,356 kWh
- PVWatts output assumes a south-facing array tilted at the latitude with no shade. East- or west-facing roofs and shade make less; run PVWatts with your own roof’s tilt and direction for a firmer number.
The same home in other cities
| City | System size | Panels | Expected output per year |
|---|---|---|---|
| Phoenix, AZ | 5.8 kW | 15 panels | 10,722 kWh |
| Los Angeles, CA | 6.1 kW | 16 panels | 10,874 kWh |
| Denver, CO | 6.33 kW | 16 panels | 10,464 kWh |
| Miami, FL | 6.67 kW | 17 panels | 10,554 kWh |
| Dallas, TX | 6.84 kW | 18 panels | 10,894 kWh |
| Chicago, IL | 7.92 kW | 20 panels | 10,464 kWh |
| New York, NY | 8.01 kW | 21 panels | 10,861 kWh |
| Seattle, WA | 9.67 kW | 25 panels | 10,710 kWh |
What to know about solar for a typical home
- Grid-tied, this is the whole answer. With net metering, panels sized to your yearly use can cover the bill without batteries — the grid acts as the storage.
- Off-grid, it is only the start. Running the same house off-grid needs batteries for nights and cloudy weeks and enough panels for winter — see an off-grid solar system for a house.
- In sunnier places, fewer panels. The same 863 kWh a month takes about 5.8 kW in Phoenix and about 9.7 kW in Seattle.
- Per day it is about 28 kWh. 10,356 kWh a year is about 28.4 kWh a day — the number to start from for backup batteries: how many kWh to power a house for a day.
For bigger bills, see how many solar panels for 1000 kWh per month and how many solar panels for 2000 kWh per month.
Different size? Use the full Solar System Size Calculator.
What you’ll need
- 400 W residential-size solar panelPremium price
Fewer, larger panels for a cabin, shed or ground mount. Their higher voltage usually means an MPPT controller.
See options on Amazon (opens in a new tab) - Plug-in electricity usage monitorBudget price
Plugs in between the wall and a 120 V appliance and shows real watts and kWh over a day — the honest way to fill in a load list, especially for fridges that cycle on and off.
See options on Amazon (opens in a new tab)
As an Amazon Associate we earn from qualifying purchases. Links to products are affiliate links — they cost you nothing extra and help keep these calculators free.
Frequently asked questions
How many solar panels to run an average house in Phoenix?
About 5.8 kW — 15 panels of 400 W.
How many 300 W solar panels to run an average house in Chicago?
About 27 panels for 7.92 kW.
Other common sizes
- How many solar panels for 1000 kWh per month — 7.93 kW — 20 × 400 W panels (Dallas)
- How many solar panels for 2000 kWh per month — 15.86 kW — 40 × 400 W panels (Dallas)
Sources
- National Laboratory of the Rockies (formerly NREL) — PVWatts® Calculator (opens in a new tab) — Look up the solar resource (peak sun hours) and yearly output for your own address; default system losses 14%.
- NLR (formerly NREL) — PVWatts® v8 API, NSRDB PSM V3 TMY data (opens in a new tab) — City figures on this site: fixed open-rack array facing due south, tilted at the site’s latitude, 14% system losses, queried October 2026.
- U.S. Energy Information Administration — Electric Sales, Revenue, and Average Price, Table 5A (2024 data, released October 2025) (opens in a new tab) — 2024 average residential customer: 863 kWh a month (about 10,359 kWh a year, 28.4 kWh a day); Louisiana 1,202 kWh a month, Hawaii 495.