Are Your Solar Panels Not Performing As Expected ? Know Why

Solar panels are the best way to be energy independent and reduce your power bill expenses. In addition to all this it comes up with lots of other benefits like it helps in reducing carbon emission. It also helps you earn tax credits and rebates. Good quality solar panels from top solar panel manufacturing companies come up with 25 years of performance warranty. Despite the many promises that solar installers and manufacturers make about the technology’s resilience, every PV system requires at least some maintenance and servicing over the 20 to 25 years of their warrantied lifetimes.

You may only know how many kilowatts of solar panels you have and then realize that the power your solar power system is producing (in kilowatts) is lower even though the skies are clear and the sun is shining bright. Unless you’re an experienced and trained solar technician, it’s very difficult to troubleshoot a non-performing solar installation as you don’t know the root cause of the problem.

In this article, we’ll explore some of the most common reasons why your solar panels have stopped performing as desired– and how can you fix the issue.

There are two failure modes which the solar system may experience. These two conditions which may require troubleshooting are:

A. Zero Power Output (No Power)

B. Low Voltage Issue

Troubleshooting zero power Output

Zero Power output is a very common problem. We get such queries from 6 out of 10 customers. But the main culprit is not always the solar panel. It is majorly due to a faulty inverter or charge controller. It’s also possible that one solar panel in your PV array failed. Since the PV Modules are connected in series, one faulty PV Modules will shut down the entire solar power system.

Troubleshooting low voltage issue

1. Faulty Solar Meter

Sometimes faulty solar meter leads to solar power system malfunctioning. In this case, your solar panels are working fine but due to some defect, your meter is not able to read the power generation correctly. It could happen as sometimes solar meter becomes obsolete with time and stop functioning, while on other hand it may also happen due to poor internet connection.

Solution - You can get the internet connection at the right place otherwise if the meter is faulty then get it replaced.

2. Shadow Effect

The shade of trees and dirt on solar panels could be the major cause of low power generation

Solution: Ensure there are no trees around your solar power plant that leads to shading. Also, keep on cleaning the solar panels at regular intervals of a month to keep them free from dirt and bird droppings. Conducting a bi-annual survey of the installation site is a good idea.

3. Length & thickness of wire

In a solar power system, several components can cause a voltage drop and wire is one of them. Wires and cables themselves have a small amount of internal resistance, the amount of which depends on the gauge (thickness) of wire as well as its length. The National Electric Code (NEC) specifies a minimum gauge for the wires based on the voltage and current involved to prevent electrical fires. NREL’s study suggests a 2% loss for DC wiring. In a solar power system, shorter wires that are used to connect solar panels and inverters, as well as thicker wires, may lead to a loss of around 1%.

4. PV connection losses

This means losses across wiring connectors and diodes. Solar panels contain bypass diodes, which let other modules on a string circumvent a panel that is shaded or otherwise poorly performing. These components have a small voltage drop, caused by the internal resistance of the material and imperfections in the contact surface.

5. Solar Panel Defects

Like all other energy-producing devices, solar panel components are also prone to damages. The most common types of solar panel defects are :

Hotspots & Microcracks

Hot spots and cracks can appear on the surface of solar panel cells. The series resistance of the solar cells in a panel could have increased over time resulting in the appearance of hotspots that may occur when micro cracks appear in the cells. The result is a lower voltage in the panel, which will bring the overall voltage of the solar array down.

PID Effect

PID or potentially induced degradation is an effect that affects the potential of the modules concerning the ground and that affects the power of the module by reducing it consistently over time. The main cause of PID is considered to be the high voltage between the encapsulated solar cells and the front glass surface, which is grounded through the frame or structure. This can lead to an unwanted migration of the charge carriers (ions/electrons), which reduces the performance of the cell. In the case of high voltages due to long string connections, the PID effect can also occur more heavily. High humidity and temperature accelerate this process. PID is a highly critical concern because it generally only develops months after the installation of the photovoltaic system. And in addition to that, unlike other module defects (such as delamination or yellowing of EVA parts), the PID is not distinguishable with the naked eye.

Delamination

Delamination is another common defect. You should be able to see delamination with your own eyes. When delamination occurs, moisture can enter the electrical circuit of the panel, which may create a current leak or a short.

Suggestion

After performing these basic troubleshooting steps, if you are not able to locate the source of the problem, it is better to call a certified electrician or your solar system installer. Keep in mind that while doing any troubleshooting, there is always a potential of getting shocked. Make sure that you wear insulating shoes and gloves when performing any such work.