Solar Panel Calculator

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Solar Panel kWh per Day Calculator

Estimate how many kWh solar panels make per year, month and day where you live.

Loads the state's average price per watt, electricity price and solar output. You can edit any of them.
Measure by
kW DC
panels
From NREL PVWatts for your state.
kWh/kW

Your result

Enter your numbers and press the button. Your result appears here.

A 400 W panel makes about 1.5 kWh a day at the U.S. average, more in the Southwest and less in the Northwest.

How it works

Yearly kWh = system kW × yearly kWh per kW. Monthly = yearly ÷ 12; daily = yearly ÷ 365.

Example: 8.00 kW makes about 10,936 kWh a year, 911 a month and 30.0 a day.

At a glance

Same settings as the calculator, changing only the panels.

PanelsPer yearPer monthPer day
1547 kWh46 kWh1.5 kWh
52,734 kWh228 kWh7.5 kWh
105,468 kWh456 kWh15.0 kWh
158,202 kWh684 kWh22.5 kWh
2010,936 kWh911 kWh30.0 kWh
2513,670 kWh1,139 kWh37.5 kWh

Common questions

How much electricity does a solar panel produce?

A 400 W panel makes about 550 kWh a year, or 1.5 kWh a day, at the U.S. average of 1,367 kWh per kW. In Arizona it is closer to 700 kWh a year.

Why is my output lower in winter?

Shorter days, a lower sun and snow cut production. The yearly figure averages the seasons.

Sources

  • NREL PVWatts v8 (20° tilt, south-facing, 14% losses), state results compiled by TheGreenWatt: https://thegreenwatt.com/average-peak-sun-hours-by-state/
  • NREL PVWatts Calculator: https://pvwatts.nrel.gov/