Easy Solar Calc

How many solar panels for 1000 kWh per month?

Short answer

Covering 1000 kWh a month (12,000 kWh a year) takes about 7.93 kW of panels at Dallas’s PVWatts output of 1,513 kWh per kW a year — 20 panels of 400 W.

How to work it out

  1. 1,000 kWh × 12 = 12,000 kWh a year
  2. ÷ 1,513 kWh per kW a year = 7.93 kW of panels
  3. 7,931 W ÷ 400 W = 20 panels

A thousand kWh a month is above the 2024 US average of about 863 (EIA) — typical of a larger home with central air, or a medium home with an electric car. The panel count depends heavily on location.

Adjust for your project

From your bill — average 12 months if you can. The 2024 US average was about 863 kWh (EIA).
PVWatts AC output for 1 kW of panels facing south, tilted at the latitude. Pick the closest, or enter your own PVWatts figure.
More options: Offset
%
System size7.93 kW
Panels
20 panels · 400 W
Expected output per year
12,104 kWh
Average output per month
1,009 kWh
Your use per year
12,000 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.

For this job · affiliate link
Plug-in electricity usage monitorBefore buying a system sized on your bill, find the big loads you could cut — every kWh saved is panels you don’t need.
View on Amazon (opens in a new tab)

The same home in other cities

The same home in other cities
CitySystem sizePanelsExpected output per year
Phoenix, AZ6.72 kW17 panels12,152 kWh
Los Angeles, CA7.06 kW18 panels12,233 kWh
Denver, CO7.34 kW19 panels12,426 kWh
Miami, FL7.73 kW20 panels12,416 kWh
Dallas, TX7.93 kW20 panels12,104 kWh
Chicago, IL9.17 kW23 panels12,034 kWh
New York, NY9.28 kW24 panels12,413 kWh
Seattle, WA11.2 kW29 panels12,424 kWh

What to know about a 1,000 kWh/month system

  • Location swings it by two-thirds. PVWatts gives about 6.7 kW in Phoenix, 7.9 kW in Dallas, 9.2 kW in Chicago and 11.2 kW in Seattle for the same 12,000 kWh.
  • Summer and winter differ. A system sized for the yearly total over-produces in summer and under-produces in winter; net metering rules decide whether that balances out on your bill.
  • Roof space. Twenty 400 W panels is a lot of roof — each is roughly door-sized. Shaded or north-facing areas don’t count.
  • Cut use first. Every 100 kWh a month you save trims about two panels at this location. Adding an EV does the opposite — how many solar panels to charge a Tesla Model Y shows roughly six more.

Bigger homes are on how many solar panels for 2000 kWh per month; the US-average home is how many solar panels to run an average house. What one 400 W panel makes is on how much power a 400W solar panel produces per day.

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 for 1000 kWh per month in Phoenix?

About 6.72 kW — 17 panels of 400 W.

How many solar panels for 1000 kWh per month in Seattle?

About 11.2 kW — 29 panels of 400 W.

How many solar panels for 900 kWh per month?

About 7.14 kW — 18 panels of 400 W at Dallas’s output.

Other common sizes

Sources