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How to test solar panels safely

Once you have decided to have solar panels installed in your home or business (a wise decision, in our opinion!) it’s important to have some knowledge on how the solar system works. Not only will you want to make sure the system is operating at maximum efficiency, but you’ll also want to be certain they are functioning correctly and safely.

While learning how to test solar panels safely is important, you should also note that solar panel ownership is a very low maintenance and a cost-effective way to generate electricity for your home. Once installed, the system can run without needing intervention, other than the occasional testing and cleaning.  

Testing your solar panels ahead of their first use is especially important, as you’ll need to be able to demonstrate that your solar system is ready and safe to operate.

Ahead of learning how to test a solar panel, our guide will help you to understand the ins and outs of what a solar system is, and how they work.

How do solar panels work?

Solar panels are made out of photovoltaic cells that convert the sun’s energy into electricity. The photovoltaic cells are layered between conducting materials, such as silicone, and each layer has different properties that energise when they are hit with sunlight. 

Solar panels generate a direct current (DC) of electricity, which is then passed through an inverter to convert it into an alternating current. This can then be used to power your home or business.

The energy solar panel’s produce is measured in watts, as this is how most household appliances measure power usage. The wattage of your solar panels is important to note when testing them as it determines the electrical output, and whether it is producing enough energy for your needs. 

Before you start

There are a couple of things you’ll need to prepare before you begin to test your solar panels. 

Find the voltage (V) and current (A) ratings of your panel. These can normally be found on the back of your solar panel system.

Check the sunlight conditions are suitable to produce readings on your system. Ideal conditions are bright clear sunlight directly on the panel.

Remember safety first when testing your solar panels. If you need to access the panels via scaffolding, it may be necessary to hire a professional, or ask for assistance from a friend or family member. 

Do I need equipment?

One of the reasons to test a solar panel is to make sure the panel output is sufficient for your needs. To calculate the panel’s production rate, you will need to measure the wattage and the voltage.

To measure this, you’ll need a solar panel tester, called an amp meter. This instrument will help you determine the electric current and output of your solar panel system. 

To measure current, you’ll need a multimeter and resistors. The multimeter will find the DC voltage. There are two types of multimeter:

Switched multimeter – this manually switches between ranges to get the most accurate reading. It has functions that measure several different quantities so be sure to set it to DC amperage or, if you wish to measure voltage, set it to DC voltage.

Auto Range multimeter – Switches between ranges automatically to gather the best reading. Auto range measures voltage and current only, so the adjustments will capture this information alone.

You’ll also need to get hold of some crocodile clips. You’ll need these to connect the multimeter to your solar panel system. 

How to measure solar panel amperage

Now that you have your equipment, and have taken the necessary steps to test solar panel output, you need to perform a simple, but specific calculation for testing the solar panels:

Volts x Amp = watts 

To determine the power the solar panel is producing, you need to measure the wattage and the voltage. 

From here, attach your amp meter to the positive and negative output on your panels, which will help you test the solar panel output. It’s important to remember to test in full sunlight so the amp meter can measure the highest amperage and garner accurate readings.

How to measure current

Using your multimeter, you can test the voltage and current of your solar panel system. It is recommended that you have a working knowledge of a multimeter before testing your solar panels, as incorrect use could potentially damage your solar system.

To learn how to test your solar panels safely, and locate your current measurement, follow the below steps:

Locate your converter box – This is found at the back of the solar panel, remove the cover to see the connections inside.

Set your multimeter to DC – Ensure you are measuring at a suitable voltage level for your solar panel. To do this, measure at higher volts than your panel is used for. For example, if your panel is approved at 20 volts, set the multimeter at a higher reading.

Connect your crocodile clips – Connect the red lead crocodile clips to the positive side, and the black lead to the negative side, then connect them.

Once these steps are completed, your multimeter should give you an accurate reading of the volts the solar panel system is producing. 

When testing a solar panel, the system must produce a voltage that is close to the one that is approved for it, especially if the system is new. If the panels are used or slightly older, the reading may be slightly lower, this is not unusual. 

Remember to disconnect the crocodile clips only after you have switched off the multimeter. 

Testing the charge controller

Now that you know how to test a solar panel safely, you’ll also need to test the charge controller. The charge controller is used in the case of solar storage. Your solar battery shouldn’t be fully charged when you come to test it as it won’t accept the current passing. 

When connecting the controller, solar panel and battery, make sure you disconnect the panel from the regulator first. Then disconnect the battery from the controller.

To test a solar panel charge controller, you must follow the below reconnection steps to avoid damage:

  • Set the measurements of the multimeter to DC amps, and make sure your crocodile clips are in the right position
  • Set the multimeter to 10 amps
  • Connect the solar panel to the controller, and the controller to the solar batteries
  • Disconnect the positive lead between the battery and controller
  • To locate the current, connect the positive cable you just removed to the crocodile clips from the multimeter
  • Connect the negative lead crocodile clip of the multimeter to the positive terminal of the solar battery

Following the above process will test the current flowing between the solar panel, controller and solar batteries. 

Now you know how to test a solar panel and charge controller, you are ready to start generating green energy for your home. Testing your solar panels is important before you start to use them, and periodically during their lifetime to ensure you are getting maximum results. 

If you’re ready to start your journey to renewable energy, get in touch with one of our expert team today.