Solar energy has rapidly become one of the most important and versatile renewable sources. Now, everything from community solar to utility-scale solar farms is capitalizing on generating energy simply by having a sunny day.

However, like any power generation tech, solar farms face several technical and operational challenges that can negatively impact overall power generation. Identifying these problems as early as possible is critical to optimize performance and extend the lifespan of every panel.

In this blog, we’ll be breaking down three common types of faults that can significantly reduce power production and revenue, and explain why regular solar farm inspections are critical to lasting success.

1. Hotspot

A hotspot occurs when one part of the solar panel becomes hotter than adjacent areas. Typically, a hotspot affects individual cells, although multi-cell hotspots are certainly possible.

Possible causes

There can be several root causes for the creation of hotspots. For example, it could be mechanical damage to the cells during installation or due to environmental stress. Another common reason is shading from trees or buildings, or uneven absorption of sunlight due to dirt, dust and bird droppings. Sometimes there are cell malfunctions due to manufacturing defects or aging of the cells.

Impact on the solar farm

Hot spots can lead to a significant decrease in the overall efficiency of the solar panel, as affected cells produce less electricity than their neighboring cells. Continuous overheating of hot spots can accelerate the degradation of the panel’s materials and shorten their lifespan. In extreme cases it can even cause a fire hazard.

2. Bypass Diode

When part of the panel is in the shade, the current produced by cells in the sunlight can be partially consumed by the shaded cells. To prevent this from happening each panel’s substring (typically three substrings in a panel) is connected to a bypass diode that when activated provides an alternative path for the current to bypass the shaded or faulty cells. But if the bypass diode itself is faulty the entire substring (typically one-third of the panel’s cells) can overheat and significantly reduce the panel’s power output.

Possible causes

Ideally the bypass diodes are functional but not activated. Besides partial shading from trees, overgrown grass and buildings, bypass diodes can be activated because of damaged cells, dirt and dust contamination and inconsistent degradation of neighboring cells. However, bypass diodes, whether part of the panel or installed in the junction box, can become faulty and malfunction due to overheating, excess wear or electrical issues.

Impact on the solar farm

While bypassed substrings stop producing power it may indicate other issues such as shading and malfunction cells, a faulty bypass diode means a bigger drop in the panel’s power production as the current is lowered to the shaded substring level. Sometimes this forces the entire string of interconnected panels to underperform. Moreover, a prolonged diode failure can cause irreversible damage to the substring cells, reducing the long-term performance of the entire panel.

3. String

String refers to a group of photovoltaic (PV) modules connected in series. In a string, the output voltage is the sum of the voltages of each individual cell or module, while the current remains the same as that of a single module. Strings are used to optimize energy production and ensure that the system operates efficiently. Proper design and management of strings are crucial for maximizing energy output and minimizing losses due to shading, mismatch, or other performance issues.

Possible causes

String issues occur due to various factors. Partial shading on one or more modules within a string can lead to reduced energy output of the entire string. Sometimes there is a mismatch in modules’ performance due to differences in modules age and quality. Incorrect or damaged wiring can disrupt the electrical flow and lead to string performance issues. Other reasons for string issues include bypass diode failures in one of the modules and inadequate string configurations that do not account for shading and other environmental issues.

Impact on the solar farm

Problems in one module can lead to significant decreases in the overall energy production of the string, increased overheating and potential damage to more panels in the string. Frequent maintenance to address and repair string performance issues can lead to increased operational and maintenance expenses. 

Frequent Inspections Are Critical for Optimal Solar Power Production

Effectively managing a solar farm requires early detection and prioritization of all the issues that can reduce power production and taking proactive steps to mitigate and repair them. 

Drone-based thermal inspections are necessary to detect hot-spots, faulty bypass diodes, string problems and other types of issues affecting the solar farm’s power production. Frequent periodic inspections are essential to ensuring long-term efficiency and profitability. 

vHive offers autonomous multi-drone solar inspections and analytics to provide a comprehensive view of your solar farms’ power anomalies. The clear insights help you prioritize and expedite repair work to ensure your performance is always at its peak.

Are you ready to optimize your solar farm’s performance? Book a demo today to see how our autonomous drone solution and AI-driven analytics can transform your solar farm.

Ready for more insights? Check out Part 2 of this series, where we explore three major physical obstructions that impact solar farm performance—and how to address them effectively.