How Many Solar Panels in California?
A typical California household using 10,500 kWh a year needs about 17 panels — a 6.5 kW system. That is 3 fewer than the national average.
Panels needed
17
5 of 51 states, fewest first
System size
6.5 kW
Roof space
306 sq ft
Peak sun hours
5.5 / day
Based on 400W panels and 10,500 kWh a year. Your own bill will differ — put your figure into the calculator.
What drives the number in California
At 5.5 peak sun hours a day, California is among the sunniest states in the country. Each kilowatt of capacity delivers about 1,606 kWh a year here, so systems are smaller and cheaper for the same output than almost anywhere else.
Roof space is usually the binding constraint rather than budget. The 306 square feet above is usable south-facing area — chimneys, vents, dormers and north-facing slopes do not count towards it.
How long would that system take to pay for itself in California? →