How to Test a Solar Panel

Suppose you were finally convinced to spring the cash for a solar panel system for your home. It’s all your neighbor spoke about every time you met them. At first it seemed like they were exaggerating the actual benefits. Then you did your own research.

There is plenty of evidence online that solar panels are a great way to reduce energy bills. Of course, they come with the added benefit of being a clean source of energy. This combination of factors presented a convincing argument.

So here we are. The panels are installed, and everyone waits in anticipation of all those savings. But wait! You’re forgetting an important step, aren’t you? Before you start using the solar panels, you should always test the output to confirm you’re receiving the power you need.

How to Test a Solar Panel

What’s the matter? Don’t know how to test a solar panel? Don’t worry! In this guide, we’ll walk you through the whole process, one step at a time.

What You’ll Need

To conduct the test, you’ll need the following items.

  • Ammeter– this device measures the amperage, or the flow of current.
  • Multi meter– essentially a more advanced version of an ammeter. While an ammeter can only measure the amperage, a multi meter can perform a wide variety of functions. You should note that if you don’t get an ammeter, it’s fine because a multi meter can perform its functions too.
  • Resistors– these act as a load for the test and prevent the circuit from shorting. Generally, resistors protect the circuit from and overheating by limiting the current to safe levels.
  • Alligator clips– these are fairly common clips, used to connect terminals. You’ve probably a bigger version for your car battery.

1. Measure the Amperage

This step will require an ammeter. An ammeter measures the flow of current across a load. You should connect the ammeter to the positive and negative terminals on the panels. Remember that current needs to be flowing through the system.

This means that the panels need to be in full sunlight and connected to a load, such as a battery. If these conditions are met, your ammeter will provide a reading. Your ammeter must be rated higher than the output of the solar panels. Otherwise, your ammeter will not be able to provide an accurate reading.

2. Measure the Current

The next step in the process is measuring current. You can do this through a multi meter. A multi meter is like a Swiss army knife, able to carry out a wide range of electrical measurements.

· Open Junction Box

Each Solar panel has a convertor box that houses all the electronic components to protect them from the environment. The box contains diodes for the solar panels which prevent reverse flow of current.

· Identify Master Terminals

Inside the junction box you will find the terminals for the panels. You only need the master terminals for your test so locate them. Ensure that the panels are receiving maximum sunlight as mentioned previously.

· Select “DC” On Your Multi meter

You should ensure that you’ve set the multi meter appropriately. This means that the multi meter should be set to measure a higher voltage than the output of the panels. We do this to increase the reliability of the measurement, and as such our confidence in the result.

· Connect Alligator Clips

Once all the previous steps are complete, connect the red lead to the positive terminal and the black one to the negative terminal. If you’ve followed the steps correctly so far, the multi meter should be giving a reading right now.

Note that older panels will produce a reading that is lower than their rating. This is normal so no need to be alarmed. Once this step is complete, make sure you switch off the multi meter and disconnect the clips.

Testing the Charge Controller

It is not enough to know just how to test a solar panel. You must also be able to test the charge controller. A solar charge controller protects your battery by providing it with varying current. It also prevents it from draining completely and overcharging.

As you can see, a solar charge controller is essential to any solar power system. As such, knowing how to test it is a key step in the process. You can follow the steps mentioned below to conduct this test.

  1. The charge controller’s output is in direct current. Set multi meter to DC amps and connect the alligator clips to their counter parts on the charge controller.
  2. Set the multi meter to ten amps.
  3. Establish a connection from the panels to the charge controller and from the controller to the battery.
  4. Disconnect the positive cable connecting the controller and battery.
  5. Reconnect this cable to the red alligator clip on the multi meter.
  6. You should now connect the black alligator clip to the positive terminal of the battery.
  7. You can now measure the current between the panel, battery and controller.

Our Final Thoughts

We’ve already seen how useful solar panels can be. They can help you save energy and reduce your carbon footprint. If you followed the steps correctly, you should now have learned how to test a solar panel. This knowledge is key in ensuring that your panels are producing the output that you’re been promised and can even be used as a quality benchmark.

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