Off-Grid Solar System Sizing Calculator

Step 1: Enter Your Zip Code

Enter your zip code*, and we'll look up the the sun hours in your area.

Winter Sun Hours/Day

*Must enter zip code to gather data.

How many Sun Hours a day do you average in the darkest month?

We’ll start by using your winter low sun hours to size your PV array. Keep in mind your exact needs may vary depending on how your system will be used.

Step 2: Fill Out Load Calculator

Fill out the table below to estimate energy usage. We’ve included some common household appliances found in off-grid homes. Try to account for everything, keeping in mind that off-grid homes should use efficient appliances, and the major heating loads (water & air heating) are usually not electric.

Unbound Solar Load Calculator

Appliance

Quantity

Watts (Volts x Amps)

Hours On per Day

Watt Hours per Day

+ Add Appliance Clear All Fields

Total Watts - (Peak Load)

Total Watt Hours per Day:

Kilowatt Hours Per Month:

kWh/mo

Step 3: Calculate Off-Grid System Size

We'll estimate your off-grid system size based on the list of appliances and energy usage that you entered. Keep in mind that this is only an estimate, and there are many factors that can influence system sizing. Please contact us for help designing your project.

Click the "Calculate My System Size button" and we'll calculate your system size.

Minimum PV

System Size

Kilowatts

This is a very general system size estimation. Other factors such as peak load, shade, location, available panel space, and seasonal use need to be taken into account.

For the most accurate and personalized off-grid system size calculation, call our solar experts at 1-800-472-1142.

We want to help you get the system that’s right for you.

Here are the results of your form submission. If you would like us to email you a copy, enter your email address below.

Thanks for partnering with Unbound Solar. A copy of your system calculation was emailed to you.

Questions? Chat with us!

Brent and his family live on a grid-tied ranch in California, powered by a 5 kW solar system he installed himself. Brent and the rest of the Unbound Solar team are here to answer any questions you have about designing a system that will fit your needs. Give us a call—we’re here to help.

1-800-472-1142

Download Our Solar Battery Guide

A poorly designed system can ruin your batteries. Our Solar Battery Guide will help you size your battery bank properly and keep things running smoothly.

Get Free Guide

Appliance	Watts
Kitchen
Blender	500
Can Opener	150
Coffee Machine	1000
Dishwasher	1200-1500
Espresso Machine	800
Freezer - Upright - 15 cu. ft.	1240 Wh/Day**
Freezer - Chest - 15 cu. ft.	1080 Wh/Day**
Fridge - 20 cu. ft. (AC)	1411 Wh/Day**
Fridge -16 cu. ft. (AC)	1200 Wh/Day**
Garbage Disposal	450
Kettle - Electric	1200
Microwave	1000
Oven - Electric	1200
Toaster	850
Toaster Oven	1200
Stand Mixer	300
Heating/Cooling
Box Fan	200
Ceiling Fan	120
Central Air Conditioner - 24,000 BTU NA	3800
Central Air Conditioner - 10,000 BTU NA	3250
Furnace Fan Blower	800
Space Heater NA	1500
Tankless Water Heater - Electric	1500
Water Heater - Electric	4500
Window Air Conditioner 10,000 BTU NA	900
Window Air Conditioner 12,000 BTU NA	1200
Well Pump - 1/3 1HP	750
Laundry
Clothes Dryer - Electric	3000
Clothes Dryer - Gas	1800
Clothes Washer	800
Iron	1200

Appliance	Watts
Living Room
Bluray Player	15
Cable Box	35
DVD Player	15
TV - LCD	150
TV - Plasma	200
Satellite Dish	25
Stereo Receiver	450
Video Game Console	150
Lights
CFL Bulb - 40 Watt Equivalent	11
CFL Bulb - 60 Watt Equivalent	18
CFL Bulb - 75 Watt Equivalent	20
CFL Bulb - 100 Watt Equivalent	30
Compact Fluorescent 20 Watt	22
Compact Fluorescent 25 Watt	28
Halogen - 40 Watt	40
Incandescent 50 Watt	50
Incandescent 100 Watt	100
LED Bulb - 40 Watt Equivalent	10
LED Bulb - 60 Watt Equivalent	13
LED Bulb - 75 watt equivalent	18
LED Bulb - 100 Watt Equivalent	23
Office
Desktop Computer (Standard)	200
Desktop Computer (Gaming)	500
Laptop	100
LCD Monitor	100
Modem	7
Modem	150
Printer	100
Router	7
Smart Phone- Recharge	6
Tablet- Recharge	8

Appliance	Watts
Tools
Band Saw - 14"	1100
Belt Sander - 3"	1000
Chain Saw - 12"	1100
Circular Saw - 7-1/4"	900
Circular Saw 8-1/4"	1400
Disc Sander - 9"	1200
Drill - 1/4"	250
Drill - 1/2"	750
Drill - 1"	100
Hedge Trimmer	450
Weed Eater	500
Misc.
Clock Radio	7
Curling Iron	150
Dehumidifier	280
Electric Shaver	15
Electric Blanket	200
Hair Dryer	1500
Humidifier	200
Radiotelephone - Receive	5
Radiotelephone - Transmit	75
Sewing Machine	100
Vacuum	1000

Note: TVs, Computers, and other devices left plugged in but not turned on still draw power.

**To estimate the number of hours that a refrigerator actually operates at its maximum wattage, divide the total time the refrigerator is plugged in by three. Refrigerators, although turned "on" all the time, actually cycle on and off as needed to maintain interior temperatures.