Solar decision guide
What size solar system do I need?
Most residential systems fall around 5–12 kW. A national-average usage walkthrough lands at 6.9 kW, but your annual kWh and roof capacity are the meaningful inputs.
- Typical range
- 5–12 kW
- Average walkthrough
- 6.9 kW
- Solar exposure basis
- 4.8 hrs/day
Broad residential range.
From the published national usage basis.
National-average sizing walkthrough.
Size from energy first, then fit the roof
Your annual kWh establishes the production target. Local solar exposure translates that target into system capacity. Orientation, shade, setbacks, and roof geometry determine how much of that capacity can be installed.
Frequently asked questions
What is a typical residential system size?
A broad typical range is 5–12 kW.
What does the national-average walkthrough produce?
About 6.9 kW for 855 kWh per month at 4.8 average peak sun hours.
Should I size only from my bill?
Use the electricity usage printed on your bills when possible. The dollar amount alone changes with local rates, and the roof may constrain the final size.
Check your specific roof
General guidance is a starting point. Use your address to check orientation, shading, and usable roof area free.