Solar Panel Calculator
As a general rule, you will need 10 watts of power for each output joule of your fence energizer. For example: 3-joule energizer = 30 watt solar panel. Use the calculations below to determine wattage needed for your energizer and location.
Step 1: Calculate the Ah per day needed
Determine wattage of the unit.
Battery voltage x Energizer amps = Watts
12v x .29A = 3.48W
Watt hours = 3.48W x 24 hours = 83.52Wh
Determine Amperage Hours
A= W/V
Ah = 83.52WHr/12V = 6.96 Ah per day
Step 2: Determine peak sun hours for your location.
For example, average sunlight near Blairsville, PA = 3.68
Step 3: Calculate which solar panel will provide the Ah per day you need.
Now divide the Ah that you need (from Step #1) by the number of Peak Sun Hours per day
Example: 6.96Ah/ 3.68Hr = 1.891A
This means that a panel that produces 1.9A is what you want. Determine Panel Size:
A = Watt/Volt
Watt = Volt x Amps
? = 12V x 1.9A
=22.8 Watts - Always add 20% to take account the real world conditions.
=27.36 Watt Panel - Round to 30 Watt Panel.
Unit (joules) |
Amp (energizer) |
Wattage (energizer) |
Wh used per day (energizer) |
Ah per day (energizer) |
Voltage Battery |
Sunlight Hours |
Amps Needed |
Solar Panel (watt) |
1J |
.10 |
1.14 |
27.36 |
2.28 |
12 |
3.68 |
.62 |
10 |
2J |
.18 |
2.16 |
51.84 |
4.32 |
12 |
3.68 |
1.17 |
20 |
3J |
.29 |
3.48 |
83.52 |
6.96 |
12 |
3.68 |
1.89 |
30 |
6J |
.7 |
8.40 |
201.60 |
16.80 |
12 |
3.68 |
4.57 |
70 |
12J |
1.1 |
13.20 |
316.80 |
26.40 |
12 |
3.68 |
7.17 |
100 |
Battery Recommendations:
Deep cycle batteries are recommended for solar powered fence systems. These batteries are designed to be discharged over a long period of time (100 hrs.) and recharged hundreds or thousands of times. To maximize battery life, deep cycle batteries should not be discharged beyond 40-50% of their capacity.
For example: A 3-joule solar fence energizer would work without sunlight for 8.6 days and only use half the capacity of the battery.
Need more help? Fast, friendly service and expert advice: 1-800-KENCOVE.