The average cost of solar panels in California is $4.11 per watt, but the average is $3.99 per watt in Southern California. While the average is $3.99, prices vary depending on the county. 

Below are the list of counties and the cost of the panels per watt. 

Orange County: $3.95 per watt 
Los Angeles County: $4.25 per watt 
Ventura County: $4:07 per watt 
Riverside County: $4.51 per watt 
San Diego County: $3.81 per watt 
San Bernardino County: $4.15 per watt 
Kern County: $3.85 per watt 
San Luis Obispo County: $3.85 per watt 
Santa Barbara County: $4.10 per watt 
Imperial County: $3.39 per watt Currently, solar panel cost in Southern California is determined mainly by the system size and roof space required:

  • A 4kw system size with an average cost per watt of $4.42 will require a roof space of 267sq/ft and an average cost of $17,676 before tax credit and an average cost of $12,373 after tax credit. 
  • A 5kw system size with an average cost of $4.26 will require a roof space of 333sq/ft and an average cost of $21,288 before tax credit and an average cost of $14,901 after tax credit. 
  • A 6kw system size with an average cost of $4.11 will require a roof space of 400sq/ft and an average cost of $24,659 before tax credit and an average cost of $17,261 after tax credit. 
  • A 8kw system size with an average cost of $3.88 will require a roof space of 533sq/ft and an average cost of $31,023 before tax credit and an average cost of $21,716 after tax credit. 
  • A 10kw system size with an average cost of $3.72 will require a roof space of 667sq/ft and an average cost of $37,225 before tax credit and an average cost of $26,058 after tax credit. 
  • A 12kw system size with an average cost of $3.58 will require a roof space of 800sq/ft and an average cost of $42,916 before tax credit and an average cost of $30,041 after tax credit. 
  • A 20kw system size with an average cost of $3.46 will require a roof space of 1333sq/ft and an average cost of $69,267 before tax credit and an average cost of $48,487 after tax credit. 

When deciding whether to purchase solar panels, one must consider other costs such as the system size, permit, and cost of labor. 

Click on the link below and enter your zip code in the solar power calculator to find out the cost of solar panels in your area and to determine how many panels you need in your home.