Solar Energy Estimator

Harness the sun. Calculate exactly how many kilowatt-hours your solar panels will produce and how much you'll save on your electric bill.

System Size (kW) Average US residential system is 5–8 kW.

Peak Sun Hours Per Day

Electricity Rate ($ / kWh) US average is ~$0.16 per kWh.

System Efficiency (%)

75% Losses from inverters/wiring

Daily Production

kWh

Monthly Savings

$96

Yearly Generation

7,300 kWh

What are "Peak Sun Hours"?

I genuinely believe that this is the most misunderstood part of solar. Peak sun hours aren't just "how long the sun is in the sky." It's a measurement of the intensity of the light. An 8-hour day of hazy light might only equal 3 "peak" sun hours. Arizona gets about 6, while Vermont might only get 3.5.

System Losses: Your 6kW system will never actually output 6kW of AC power. You lose about 10% in the inverter, another 5% in the wiring, and about 0.5% every year as the panels age. That’s why I’ve set the default efficiency to 75%—it’s the "real world" number.

Solar Tips:

Orientation: South-facing panels produce the most energy in the Northern Hemisphere.
Shading: Even a small shadow from a chimney can drop a panel's output by 50% or more.
Incentives: In the US, the Federal Solar Tax Credit (ITC) can cover up to 30% of the installation cost. Don't forget to factor that into your ROI!