The Homestead Calculator

Solar Panel Needs Estimator

Select your appliances, enter your location's sun hours, and get a complete off-grid or grid-tied solar system recommendation — panels, battery bank, inverter, and cost estimate.

Step 1 — Location & System Type

Peak Sun Hours / Day

System Type

Panel Wattage

Days of Battery Backup

Step 2 — Select Your Appliances

Check each appliance you use and adjust hours per day as needed.

Custom Appliance (optional)

Daily Energy Load Breakdown

Appliance	Watts	Hrs/Day	Wh/Day	Load Share

Estimated System Cost

Peak Sun Hours by Region 6+ hrs: AZ, NV, NM, W. TX
5–6 hrs: CA, CO, UT, KS, OK
4–5 hrs: Most of the South, Plains
3.5–4 hrs: Midwest, Mid-Atlantic
3–3.5 hrs: Northeast, Great Lakes, Pacific NW

These are annual averages. Summer is higher, winter lower. Off-grid systems should be sized for winter minimums.

Key Terms Wh/day: Watt-hours — your total daily energy use.

Peak sun hours: Hours per day when sunlight is strong enough for full panel output (not just daylight hours).

DoD: Depth of discharge — lithium batteries can use ~80–90%; lead-acid only ~50%. This calculator uses 80% DoD.

💧 Rainwater Collection 🥕 Garden Bed Planner

Frequently Asked Questions

How many solar panels do I need to go off-grid?

It depends on your daily energy use and your location's peak sun hours. A typical homestead using 3–5 kWh per day needs 8–15 standard 400W panels in most US locations. Use the calculator above to enter your specific appliances for an accurate count.

What is a peak sun hour?

A peak sun hour is one hour of sunlight at an intensity of 1,000 watts per square meter — the standard used to rate solar panel output. The US averages 4–5 peak sun hours per day, ranging from about 3 hours in the Pacific Northwest to 6+ hours in the desert Southwest.

Do I need batteries for an off-grid solar system?

Yes — batteries are required for off-grid systems since solar panels only produce power when the sun shines. Most off-grid homesteads use lithium iron phosphate (LFP) batteries sized for 2–5 days of autonomy. Grid-tied systems do not require batteries but won't power your home during grid outages.