Defect #4 Fading Labels And Barcodes
According to IEC standards, every solar module needs to have a barcode encapsulated inside the PV module behind the glass.
This is important because in case of a warranty claim, youll need to present the barcode number to the manufacturer.
Nowadays most professional manufacturers have databases where they can trace the date the module was bought, check the Bill of Materials and which distributor bought the module.
What if the barcode is not included inside the solar module?
In that case you better have a high quality barcode and label on the outside .
If you want to check the quality of these labels on the outside, you can simply rub the label for a couple of seconds with some pure alcohol and a cloth. If the text/ barcode comes off, the manufacturer used a cheap label and needs to replace these.
Still happens a lot!
Here an example of a non-compliant barcode:
solar panel defect 4 fading labels
How To Check Solar Panel Polarity:
To check solar panel polarity, you need a voltmeter or multimeter. First, you need to turn off the power going into your DC circuit breaker box. Then, head outside and remove the covers protecting your PV panels wiring terminals.
Now, place one probe from your voltmeter onto each of the two-terminal leads connected to an individual PV module. If both probes read positive voltage, this side of the generator has positive charges, and negative charges are on the other side.
This voltage difference allows for electric current to flow through wires from one end to another, which produces electricity! In other words, you have correctly identified positive and negative polarity.
How To Test A Solar Panel: A Step
Solar panel installation is on the rise these days. It is not only easy to install solar panels for your home but after technological advances, it becomes pocket-friendly too. Also, pricing is decreasing continuously.
While installing a solar panel, you should check its output to ensure that you are getting the power youll need.
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If You Have Online Monitoring Check The Performance On There
Many newer inverters come with online monitoring, ie Fronius/SMA. This is a really good way of seeing how your system has been performing, over time.
Here you can see an example of a graph you can get on Fronius Solarweb. Solarweb is the online reporting/ monitoring tool that is available with all the newer Fronius inverters. This graph is showing the number of kwh made for each day during the month of January.
To Measure Operating Current Amps :
- Connect the panel to the regulator and battery.
- Ensure that the multimeter is set at 10A, at least to start with. You can change the setting later if required.
- Disconnect the positive cable between the battery and the regulator
- Measure the operating current by connecting the +ve from the multimeter to the positive cable from the regulator, and the -ve from the meter to the positive battery terminal.
- This measures the current that the panel are passed to the battery. If you connect the meter the wrong way round then you will get a negative current showing.
- Remember, if the battery is full it may not be accepting current, resulting in a low reading.
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What You Should Know About Solar Panel Systems
Electrical current is usually under two categories: alternating current or AC and direct current, also known as DC. While DC only flows in one direction, AC keeps reversing. Solar panel output is measured in watts because most household appliances use power in this format.
Volts x Amp = Watts.
Therefore, to calculate the panels output, you have to determine the voltage and amperage.
Solar panels have photovoltaic cells that convert sunlight into electricity. The cells are mostly made of silicon a semi-conductive material. The electric current produced by a solar panel usually goes into an inverter.
Although solar panels generate DC electricity, most homes need it in AC format. Therefore, the inverters work is to convert electricity from DC to AC.
The good news is that theres no wastage with solar. Why? The utility sends any excess electricity to the primary grid. Those who produce more than they consume get credit for the excess. Those who use more than they generate, pull the excess energy. This crediting system comes in handy when tied to a grid, especially during the night.
Know About Solar Panel Systems
Before testing solar panels, you should first know some things about solar panel systems,
Lets see what are these:
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Third Solar Site Check Check For Shading
Next, a good location has a solar window with minimal shading from 9 am to 3 pm. Shading really knocks down the production. Here is what the southern view is from the roof. Notice the large maple tree directly south of the proposed site?
If the shading is low enough on the horizon, it isnt much of a factor. It may affect winter production, but summer is what we are most concerned with. This tree is mature and will grow vertically very little. Young trees that are closer are more a concern.
The basic tool for determining shading of a site is a Solar Pathfinder. It is a low tech device that works really well. A high tech tool used by many professionals is the Solmetric SunEye. I have a Pathfinder and have not had a need to upgrade and spend the extra $2000. There also is an I-phone app by Solmetric. Both tools show the necessary shading information. I also have the Pathfinder Assistant software to analyze the shading and generate a report showing how much shading there is month-by-month .
At the top of the post is an image taken of the Solar Pathfinder. The photo is taken facing directly down onto the reflective bubble. If you look closely, you can see the trees on the horizon. Below is a shading analysis of the first picture.
So now we know we have a decent location time to take the next step. In the next article we’ll look at options to make you solar electric system more affordable.
How Do You Test Dc Polarity
There are several ways to test DC polarity. You can attach a voltmeter or multimeter to your generators output leads at the terminals.
Then, you will need to turn off the power going into your DC circuit breaker box before removing covers protecting wiring terminals on PV modules outside. Now place probes from your multimeter onto each of two-terminal leads connected to an individual PV module.
If both probes read positive voltage, this side of the generator has positive charges, and negative charges are on the other side!
This voltage difference allows for electric current to flow through wires from one end to another, which produces electricity!
This is correct solar panel polarity so continue testing all panels with the same method. If they are wired in reverse, your system will produce less electricity, and you wont get the most out of every PV module.
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How To Check Solar Panels Are Working
We constantly get calls from solar system owners, who think their solar is not performing as it should, but really have no idea whether it is working properly or not.
A lot of people ignore their solar until they get a bill, when they are either happy with the result, or they either find out the system has stopped working, or they havent got as many credits as they believe they should. How do you know whether or not you do have a problem?
How To Test Solar Panels For Volts Using A Digital Multimeter
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Check With Your Solar Company
Your solar company may provide solar system repairs, depending on the terms of your agreement. Sunruns flexible solar plans include comprehensive system monitoring and maintenance and Sunruns worry-free warranty. If it looks like your panels or solar battery arent working at their full capacity, well send someone over to fix it for free.
As the countrys #1 residential solar company, were here to help you enjoy all the benefits solar has to offer. Find out how to take back control of your energy with Sunrun. If solar sounds right for you, contact our Solar Advisors today for a free quote.
Understanding Of Factors Affecting Solar Panel Output
Manufacturers provide technical information about their solar panels, including wattage, amperes, and voltage.
However, these figures represent the ideal circumstances, such as a 25-degree Celsius environmental temperature and non-deteriorating solar panels.
Your solar panels ability to convert solar energy to electricity is a crucial factor. No solar cell can convert 100% of absorbed light energy, generating only 20% at most.
Different locations also have varying amounts of sunlight hitting the ground surface, affecting the solar panels power output. For example, solar panels in colder regions have a lower electrical yield than systems in warmer locations.
There is also the effect of wear on solar panel efficiency. Solar panels deteriorate over time, reducing their power output by as much as 0.8% annually. Some high-end products have an output reduction of only 0.3%.
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First Solar Site Check Find True South
Before you hire a site assessor, there are some basics you can check yourself. A good site for a PV array in the northern hemisphere has a location that is within 10° of true south. Remember that true south can be widely different than magnetic south. The US Geological Survey has a map showing the declination lines. Along the Mississippi River, True North and Magnetic North are close enough to ignore. In California, they are from 12° to 17° off.
Load Testing The Panel:
There may be some instances where the above tests will give results within the specifications, however applying load to a panel can expose hidden faults.
In this case a simple visual test can be done using 2 x 12V 21W globes in series or 1 x 24V 55W incandescent globe .
Connect the globes wires to the positive and negative wires of the panel . The globe should illuminate brightly if the panel is working correctly and full sun is available. Failure to illuminate may indicate a faulty panel or connection.
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Are Folding Solar Panels Worth It
The Dokio range of monocrystalline folding solar panels are well-known for their efficiency of around 25%. The 80 watt model shown here has an active area of 570mm x 540, so less than a third of a square meter is pushing out 80 watts, plus or minus 3%, with an STC rated irradiance of 1000W/m2.
However, we know this figure is unreasonable that why were testing! Here are the numbers:
The panel spec sheet indicates that Imp for the Dokio 80W is 95% of Isc.
So, for a measured irradiance of 335W/m2:
- Measured Isc = 1.57 amps
- Imp = 1.57 x 0.95 = 1.5 amps
Vmp is given as 18v, max power for this panel at 335W/m2:
- 18 volts x 1.5 = 27 watts
Adjusting for STC and NOCT:
- For STC 27 watts x 1000/335W per sq meter = 80.6 watts power rating
- For SOCT 27 watts x 800/335W per sq meter = 64.5 watts power rating
Testing The Charge Controller
When testing solar panels you should also test the controller. This is important in the case of solar plus storage. You can do this with a few easy steps.
This test will measure the current passing between the panel and controller and to the battery.
If you need a battery, check out these best batteries for solar panels.
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A Guarantee Of Reliability
Normative standards are a guarantee of reliability for solar photovoltaic modules also installers and manufacturers should be able to provide you with the quality certificates for their solar panels they offer. There is also the possibility to directly download the certificates and attestation of conformity and test directly on the website of the manufacturers, for example the certificates for the manufacturer Qcells.The TUV certificate ensures that the photovoltaic module has successfully passed the rigorous tests carried out by the German TUV laboratory proving its resistance to extreme temperatures, accelerated aging cycles, violent splashes and fire.
Solar Panel Testing For Amps
To test solar panel amperage output, put your solar panel in direct sunlight, set your multi-meter to the “amps” setting and…
That’s all there is to testing solar panels and making sure they work right!
After doing your solar panel testing, you should find that the solar panel output is about 18 volts and 3.5 amps.
Whenever you have these two values you can figure out the wattage by multiplying them together.
Volts x Amps = Watts
So… 18 Volts x 3.5 Amps = 63 Watts
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Precautions Before Testing Solar Panels
When any of the conducting parts are active with electricity generated by the suns energy, they can cause injuries associated with electric shock and arc-flash.
Even low-light conditions can create a voltage that will be sufficient to cause an injury.
The following safety measures have to be taken while testing solar panels:
Defect #5 External Particles Inside The Solar Module
Another defect you can easily spot yourself are external particles inside the solar module.
These particles may vary, including simple soldering debris , cloth or even insects.
Similar to previous visual defects: if you spot such problem, it means a manufacturer is much likely neglecting simple quality checking procedures and there may be other problems.
Debris the size as per below sample picture will have the same effect as shading and will, due to the cell-string structure of solar modules, affect its performance significantly.
Moreover, with the exposure of the solar module to sunlight, the particle may heat up, even burn, cause severe damage to the module and moreover the whole system and project
Here an example of an external particle between cell and glass:
solar panel defect 5 debris inside solar panel
For any professional PV buyer it remains unclear if a solar module was made with the right best practices manufacturing processes in place, where it was manufactured and if certified grade A components were used.
So how can you be 100% sure you purchase quality solar modules?
As youve seen from the 5 Defects above, its possible to perform basic visual quality control by yourself. Its a first indicator for the quality of the product you bought. Of course, there are many more potential defects that can severely impact the quality of your solar panel
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Are Solar Panels Energy Negative
Some solar panels are made to be energy negative, which means they take in more electrical power than they generate.
This is a good thing because it allows you to store excess energy from your system for later use or sale back onto the grid this makes switching over to renewable sources of electricity easier!
To prevent this, make sure not only that all PV modules have correct wiring in terms of positive/negative polarities but also refer back to step one and identify which wire corresponds to positive voltage so that when connecting leads from voltmeter onto DC circuit breaker box terminals inside where wires enter the house, you can attach positive probe to the terminal with the corresponding color of wire and negative lead on other.
If red was initially connected to the negative , then switch it so that black is attached instead! Then reconnect covers over wiring terminals after checking again for proper polarity.