Solar Panels for 40 kWh/Day in Low-Sun Climate
In a region with only 4 peak sun hours, powering a 40 kWh/day home requires about 31 panels at 400W.
How to use this tool
- Find your daily kWh use on your electricity bill and enter it.
- Enter the wattage of the solar panels you plan to use.
- Enter peak sun hours for your location (find these on solar resource maps).
- Set system efficiency at 80% as a conservative starting estimate.
Find out how many solar panels you need if you live in a cloudier region with fewer peak sun hours.
Frequently asked questions
- How many solar panels do I need?
- Divide your daily kWh consumption by the energy produced per panel per day (panel kW × peak sun hours × efficiency). Round up to the nearest whole panel.
- How many peak sun hours does my location get?
- The US averages 4–6 peak sun hours per day. Arizona and Nevada can exceed 6.5. The Pacific Northwest and Northeast average 3.5–4.5 hours.