How To Test A Solar Panel?

The decision to switch over to a solar power system instead of your regular source of electricity is increasingly getting popular. Solar power has become immensely recognized in recent years due to all the benefits that it has to offer. However, the first and foremost thing that may come to your mind while choosing to install the solar panels is often the question: How to test the solar panels? 

Although many people tend to ignore the process and jump off straight to the installation procedure, it is essential to check the panel’s output to save yourself from the installation of non-functional ones. Therefore, let’s find out how to test a solar panel, going further in to this blog. 

Things To Check Before You Test A Solar Panel

First and most importantly, you must find out the proper voltage and current ratings of the solar panels. Although you can find the information sometimes at the back of the panels, you can also find the ratings manually all by yourself. For that, you will need to ensure that sunlight is hitting the panels directly with strong rays and the help of a multimeter. 

Multimeter helps to generate accurate readings, and additionally, you will only be able to test a charge controller when the battery is not full. Moving on, to avoid damaging the solar panels, you must always connect the regulator to the battery first and then to the panel. 

Things You Should Know About Solar Panels

Although solar panel tech might seem a little overwhelming but it’s really not when you dedicate yourself to learning about how solar panels work and what you’re signing up for while getting them. Electrical current falls under two categories: alternating current or AC, which keeps reversing its direction, and direct current or DC, which flows only in one direction. Solar panels usually use power in the format (Volts X Amp = Watts), and thus, their output is measured in watts. Therefore, to calculate the panel’s output, one has to determine the voltage and amperage.

1. How to Test the Amperage of the Solar Panel?

For this, you will require an amp meter which is usually attached to the solar panel, to obtain the correct amperage reading. Test the panel under direct sunlight, and don’t buy an amp meter that is lower than the solar panel’s output. 

2. How to Test the Voltage of the Solar Panel?

For this, you will require a multimeter and registers. You will need a good quality multimeter, preferably the one that can read current and voltage; a variable resistance box to know the settings while fixed in the circuit; and a proper place to record the readings like the spreadsheet program, a paper, and a pen. Finally, you will also require short lengths of wire for securing the connection. Although solar panels generate direct currents, most home appliances work using alternate currents. This is why we use an inverter that converts electricity from DC to AC. 

How To Use A Multimeter To Test A Solar Panel?

To begin with, a multimeter is a handheld device used to determine amperage, voltage, and other similar values. One of the most common types of multimeters is the one with digital facilities and offers more advanced functions than a traditional analog model. Although one might go for an analog multimeter because it’s cheaper, it isn’t easy to interpret accurately.

1. Find the Converter Box

The converter box can be found at the back of the solar panel and once you find it, make sure to remove the cover to see the wiring inside clearly. This, therefore, will help to see the positive and negative connections correctly and angle the panel in the direction of the sun. 

2. Master Positive and Negative Connections

It is extremely important to master positive and negative connections to ensure the excellent performance of your solar panels. Once you discover the connections, your next step should ensure that your solar panel receives proper and direct sunlight. Tilt the solar panel for your solar panel to have complete sunlight exposure.

3. Set Multimeter to DC

Remember to set your multimeter settings up higher than the solar panel’s voltage. You have to keep in mind that your multimeter settings should be higher than your panel’s voltage, and the details of the panel’s voltage rating are usually inside the converter box. For example, if the solar panel runs for 30 volts, you have to set the multimeter to have a higher reading.

4. Connect Alligator Clips

First, you have to clip the red lead of the alligator clips on the positive side and then the black on the negative. This way, the multimeter will provide a proper reading to display the output of the solar panel. The readings come off as strong when the panels are new and lower if they have been in use before.

5. Testing A 12 V Solar Panel

Most solar panels generally come with a 12v rating, which are the most common ones to test. Therefore, in simple words, you have to test a 12v solar panel. For that, you must ensure the meter is set at 200 volts DC before beginning. Additionally, an overload indicates the need for turning up the DC volts. 

6. Testing the Charge Controller

A solar charge controller is a regulator that precisely keeps the voltage of solar panels in check to avoid the overcharging of its batteries. However, they are not usually required on occasions while dealing with small panels up to 5 watts. They usually come in two categories. A pulse width modulation (PWM) for achieving maximum power point tracking (MPPT) is pretty simple to use. On the other hand, MPPTs are more advanced since they find the best operating voltage to produce the most power. 

Therefore, coming back to the process, make sure that the battery is not fully charged while testing to avoid the cancelation of current passing. While connecting the controller, solar panel, and battery together, make sure to disconnect the panel from the regulator first. 

Common Solar Panel Problems You Can Face

1. Low Efficiency

There may be many factors contributing to the low efficiency of solar panels. Primarily, the sun emits energy in light, which contains photons used by the solar cells to obtain energy and transforms it into electricity. However, the basic problem with the efficiency of the solar cell is the physical conversion of this solar energy. Thus, if there is a solar irradiance of 1,000 watts per square meter, then the maximum power output that the solar panel can produce is 337 watts per square meter. 

Another critical point is that insulation can also affect the solar module efficiency because current leakages can occur along the edges of solar panels. Thus, insulation resistance is an extremely important point as higher voltage systems need better insulation properties. Similarly, higher temperatures, such as extreme heat, can also cause electrical losses and voltage drops.

Additionally, the orientation of the solar panels and the presence of a solar tracking system have a greater impact on the overall efficiency and performance of the solar panels. Also, dust and dirt are the true enemies of solar panels as their contaminating elements that can greatly influence their efficiency values. Therefore, it is of utmost importance to keep the panels clean and free of any dust or dirt residues. 

However, the main difference in solar panels’ efficiency values of different panel types is the nature of how they are manufactured. 

2. Faulty Wiring

Faulty wiring issues or loose connections can prevent the solar panels from good performance. If there are visible corroded cables, you must contact an electrician to sort out the problem. 

3. Cracks on The Solar Panels

Although the cracks on the solar panel are usually so tiny that they can be easily missed out on, the damages generally grow more extensive, primarily due to the impact of weather. Often, small cracks occur while shipping the solar panels as a result of being mishandled.

4. Hot Spots

Hot spots are dangerous for your solar panels and may have the power to even destroy the entire solar system at once. Therefore, ensure that the panels are never overheated or overloaded and keep it free from dirt and dust. Residues of dirt on the panels and poorly soldered joints can also cause hot spots.

5. Inverter Issues

Solar panels are known to have a considerably long shelf life, anywhere between 20-30 years. However, inverters, on the contrary, are short-lived, approximately 10-15 years. Thus, if your inverter starts to behave funny, it’s time for you to get it replaced. You may check the manufacturer’s terms or consider checking for a warranty to get a replacement.

Despite these minor inconveniences, it is totally worth installing solar panels. The upsides far outweigh these trivial cons.

Conclusion

Thus, to conclude, although it may sound all difficult on the first go, testing solar panels is relatively easy and convenient. First, you have to understand how the solar panels work, their output, and your requirements. Second, you have to learn to use a multimeter to obtain accurate readings of the solar panels. Thus, once you get a green signal after satisfactory readings from testing, you’re good to go ahead and proceed with your solar panel installation.