Curious to know how much power a 120 watt solar panel produce? how many amps, volts, and watts in a day?
After using solar panels for more than a year now, I can give an estimated output from a 120 watt solar panel based on your location.
Need an easy solution? Use our free solar panel output calculator to find out the energy output of 120 watt solar panel.
How are solar panels tested?
Solar panels are rated their power output based on standard test conditions (STC), performed in a controlled laboratory environment.
STC includes: 1kW/m2 of solar radiation (peak sun hour), 25oC temperature, and 1.5 air mass.
We can not control other factors like temperature, and air mass. But we can measure the number of peak sun hours (solar radiation) a location receives with the help of PV watts calculator by NREL.
Step 1: Enter your location (complete address or just city name) and click GO>>.
Step 2: Confirm the location with the help of a map and click “RESULTS”.
Step 3: Now you will see the average amount of solar radiation your location receives on monthly basis.
1 peak sun hour = 1kW/m2 of solar radiation.
Note: In real world conditions, on average, you’d receive about 80% of a solar panel’s rated power output in one peak sun hour (1kW/m2 solar radiation).
I have explained peak sun hours and solar panel output in detail. << Click here to learn more… >>
How Much Power Does a 120w Solar Panel Produce?
On average, A 120 watt solar panel produces about 500 – 700 watt-hours of power in a day. The exact value will depend on the number of peak sun hours your solar panel receives.
Formula: Solar panel output = (Solar Panel rated wattage × Peak sun hours) × 0.8
Let’s suppose, on average your location receives about 6 peak sun hours (6kWh/m2 solar radiations) daily.
(120 × 6) × 0.8720 × 0.8120 watt solar panel output: 576 watt-hours (Wh)120 watt solar panel how many amps?
A 12v 120 watt solar panel will produce about 35 – 50 amps daily. The exact value will depend on the number of peak sun hours your location receives.
Formula: Amps = Watts ÷ Volts.
Amp (A) is the unit for measuring current. Usually, battery capacity is measured in amp-hours (Ah). Calculating the amps’ output of a 120 watt solar panel will give you an idea of how much power is being stored in your battery.
Related post: Solar Panel Amps Calculator (Watts to Amps)
How many volts does a 120 watt solar panel produce?
A 12v 120w solar panel will produce about 18 – 18.5 volts under ideal conditions (STC).
Formula: Voltage = Watts ÷ Amps.
A solar panel will produce a higher voltage when exposed to the sun. So to charge a battery, you need a charge controller. Which will drop the voltage from 18v to 12v to safely charge a 12v battery.
AC vs DC watts
Solar panels produce power in direct current (DC), and batteries also store power in DC. But, most of our household appliances required AC (alternating current).
To convert DC into AC, we use an inverter. And like the other electronics, the inverters are also not 100% efficient. Most of them are about 85-90% efficient. This means there will be a 10-15% percent power loss when converting DC into AC.
Let’s convert the above calculated DC value into AC based on a 90% efficient inverter.
576 * 0.9 = 518 AC watt-hoursRelated Post: Solar DC Watts To AC Watts Calculator
How many watts does a 120 watt solar panel produce? – chart
Here’s a table on how many watts does a 120 watt solar panel produce daily.
| Peak Sun Hours | 120 watt solar panel estimated output |
|---|---|
| 4 peak sun hours | 380 watt-hours |
| 4.5 peak sun hours | 430 watt-hours |
| 5 peak sun hours | 480 watt-hours |
| 5.5 peak sun hours | 530 watt-hours |
| 6 peak sun hours | 580 watt-hours |
| 6.5 peak sun hours | 625 watt-hours |
| 7 peak sun hours | 670 watt-hours |
6 Tips To Improve Solar Panel Efficiency
Follow these tips to get the most out of your 120w solar panel.
- Keep your solar panels clean.
- Avoid installing solar panels in shaded areas.
- Use an MPPT charge controller instead of PWM.
- Use the right size wiring for your solar system.
- Place your solar panels at a right tilt angle.
- Avoid getting black colored solar panels, in summer they’ll be less efficient.
Related FAQ’s
120 watts are equal to 10 amps @12 volts. You can run a 120 watt appliance for an hour with 120 watt stored power.
120 watt solar panel will about 6.2 peak sun hours to fully charge a 12v 50ah car battery from 100% depth of discharge.
Yes, a 120 watt solar can charge a 100ah battery. It will take about 12-14 peak sun hours to fully charge the 100Ah battery from 100% depth of discharge.
I hope this post was helpful to you, if you have any queries or suggestions contact us, Thank you!
