Key takeaways
- Start with daily watt-hours used.
- Panel size depends on peak sun hours.
- Battery size depends on backup time.
Sizing guide
How to size a solar system
Use this simple sizing flow: calculate daily energy use, size panels for sun hours, and choose battery capacity.
Step 1: Calculate daily load
Add up appliance wattage and daily hours of use. Multiply watts by hours to get watt-hours (Wh).
Example: 100W x 5 hours = 500Wh
Step 2: Size solar panels
Divide daily Wh by average peak sun hours to estimate needed panel watts.
Solar panel output calculator →Step 3: Size batteries
Choose a battery bank to cover the number of hours or days you want in reserve.
Battery capacity calculator →