How to Test a Solar Panel Output

Last Updated: July 31, 2022

The installation of solar panels is a great initiative to protect the environment and save money at the same time. With the exponential growth and technological innovations, the solar panel market is expanding business in every corner. Today we’ll be covering how to test a solar panel output.

Once installed, it is necessary to test your solar panels to ensure their safety and quality. These items can easily last for nearly 30 years if cared for and maintained. The process of testing is not complicated.

This article aims to provide basic ways of testing the output of your solar panel, irrespective of the brand. There is a breakdown of components required for testing and understanding the panels involving the need, procedure, and electrical concepts of testing output.

Why Should Solar Panels be Tested?

There are many reasons why Solar Panel testing is necessary; some of them are listed below:

1. Corrosion

As solar panels are usually placed out in the open, there is a high chance of corrosion and contamination from certain elements. With the passage of time, this can have detrimental effects on the panels’ performance.

Therefore, it is important to test the performance systematically to get an idea if the solar panels have started to corrode.

2. Environmental Effects

There can be many environmental harms to the panels which are not entirely under your control. The hanging wires of the panels can be jeopardized if vegetation grows over or around them. Similarly, rainwater can also cause disturbances in its function.

Small animals and rodents often crawl inside the framework and chew or break it internally, which exposes the wires. This increased the chances of hazards and compromised performance. It is advised to test the panels electrically to identify faults in time.

3. Verification

Testing solar panels is a crucial element of law in certain areas. This law requires periodic verification and electric testing to improve or repair the panel system. Some solar panels have features that must be updated to match the requirements.

4. Warranty

The warranty maintenance is sometimes only possible through regular testing of the solar panel network. These come under warranty conditions. Noncompliance with them can endanger the protection that will require future replacements.

5. Fire Hazards

Due to constant exposure to sunlight, there might be a chance for the panels to catch fire. Periodic maintenance and regular testing are required to assess the panels’ function to predict any such occurrences and be rid of them.

Testing A Solar Panel

Testing solar panels is simple, requiring knowledge of certain concepts. The most important thing to remember is the formula that helps in the calculation of solar power:

Solar power (watts) = Current (amps) x Electric Potential (volts)

  • Watt

A watt is a unit used to measure the power of the electric source. The strength of wattage defines the electric output in the panel.

  • Electric Output

The net electricity being generated to be delivered in a given time is the output of that source. It is mostly measured in watts, so it essentially becomes the solar power measurement with the delivery of its efficiency.

  • Current

The current is the flow of electricity in the circuit. The net flow of the charge can be measured on a surface and then be denoted as ‘Current.’ It helps measure solar power.

  • Ampere

An amp is a unit to measure the electromagnetic force running in the electric current between conductors. The quality of current can be assessed through amperes.

  • Voltage

The pressure exerted by the source in the form of electricity can be considered as the voltage of that source. It provides information about the energy available and the potential in a panel. Solar panels come in 12 and 24 volts.

Determining the Amperes of a Solar Panel

To test the working efficiency of a solar panel, you can conduct a short circuit current (ISC) test. It is a good predictor of any dysfunctionality that might arise. This process might require you to invest in a machine known as the ‘multimeter,’ which is inexpensive and readily available.

Start by reading the specs label to find the ISC in amps. In the next step, set the multimeter to the charging amps. The solar panel’s short circuit current should be less than the multimeter’s fuse range to avoid overloading.

Take the panel out in broad daylight. Attach the multimeter probes to the MC4 connectors; the spark will indicate they are attached appropriately. The multimeter will show the ampere reading that will decipher if it is near the short circuit reading on the specs label. The closer the values are to one another, the lesser the chances of wearing off in the panel.

Determining the Voltage of a Solar Panel

The process will require you to grab the multimeter again, but this time for different usage. To start, find out the panel’s open-circuit voltage (Voc) that will be mentioned at the back. The upcoming procedure will decipher the direct current voltage (DC) for you.

Now plug the back of the probe in the multimeter at the COM terminal. At the same time, the red probe will go into the voltage terminal. Now, set the multimeter to DC from the settings. After plugging, take the panel under direct sunlight.

Find out the negative and positive cables on the panel. The cable with a red band is the positive MV4 male connector, as mentioned above. The negative cable will be slightly different and will not contain any red bands.

Next, the red probe goes inside the MC4 connector of the solar panel’s metal pin. Similarly, the black probe will be attached to the pin inside the negative MC4 connector. Once the setup is completed, the multimeter will start showing the voltage.

If the voltage is close to the listed Voc at the back of the panel, then the solar panel is working and accurately supplying the required voltage.

Solar Output Measurement

After deciding on the amperes and volts of your solar panel network, it is time to assess its solar output finally. The process will require the same formula stated above. It will provide the power rating in watts.

Solar power (watts) = Current (amps) x Electric Potential (volts)

Solar Panel Kits

If you are new to the solar power system and require some knowledge, we recommend you start with a solar panel kit. These kits are inexpensive and easy to use, having everything you need to begin with. Simultaneously, apart from the solar panels, a charge controller, battery, power inverter, connectors, solar generator, and cables are provided to assemble the unit. Once done, you can begin with the calculation of power output ahead.


As inflation rises all over the globe, it is smart to invest in technology that not only saves money but also provides stability in the environment. If you have decided to get your hands on a solar panel network, you should also test them to always be on the safe side.

Testing the solar panels might seem like a difficult process, but as seen above, it is not. Having an idea about the performance of solar panels in the installed area is a good step toward the maintenance and longevity of the product.

Moreover, knowing the output before power production is safe for the appliances too. This smart step optimizes performance and prepares you to make the most of your investment. Everyone requires a high-capacity factor after spending money on the future, and it is only clever to assess it in the right amount of time.

We hope the above discussion was helpful for you in evaluating the solar power output of your panels. How did it go for you? Let us know in the comments.

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