Startling data: Power loss in photovoltaic projects has doubled in 5 years; three major culprits have emerged.

New data from Raptor Maps, a US-based solar asset analytics firm, shows that despite a maturing market and technological advancements, power losses in solar photovoltaic (PV) projects have more than doubled in the past five years.

According to Raptor Maps' newly released Global Solar Report, the "device-driven power loss rate" for PV projects of all sizes is projected to reach 5.08% in 2025, more than double the 2.36% in 2021.

The report states, "The average power loss rate for solar assets is expected to decline, not rise, as technologies mature, such as solar panels becoming more efficient than ever before." The company identified three main factors contributing to the increase in power losses: the mechanical complexity of projects, labor supply, and manufacturing quality.

The last factor has become a focal point of discussion in industry media and among industry professionals. In January of this year, Kiwa PI Berlin found a "significant and worrying increase" in PV module defects, with over 3.36% of modules having problems before leaving the factory. This is primarily attributed to the emergence of numerous new manufacturing plants in new regions in response to changes in supply chain policies (especially those related to the US).

Raptor Maps states that the increasing mechanical complexity of photovoltaic (PV) projects has led to a corresponding increase in the likelihood of failures. The company highlights the shift from fixed-tilt mounts to active tracking systems. The report states, "While tracking mounts increase power generation, they also introduce more points of failure, including components such as motors, sensors, and controllers, all of which require continuous calibration and maintenance." The report also notes that labor shortages have outpaced the expansion of PV capacity, resulting in widespread staffing difficulties for operation and maintenance companies. The report states that in 2025, the average PV capacity handled by a technician will have increased by 70% compared to five years prior. Raptor Maps notes in the report, "Over the past five years, employment in the U.S. solar industry has grown by 12%, while installed capacity has increased by 286%." In its analysis of the U.S. market, the report indicates that these performance issues exist in PV projects of all sizes across various regions of the United States.

Equipment Issues: In 2025, the mechanical and equipment issues affecting PV power generation performance have changed. Raptor Maps points out that although inverters "have historically been the leading cause of DC-side capacity loss," power losses due to inverter failures decreased by approximately 40% year-on-year last year, accounting for less than a quarter of equipment-related power losses.

In contrast, string and combiner box failures increased by 12.5% ​​and 10.2% year-on-year, respectively, accounting for 26.89% and 21.51% of observed total power losses.

The most significant increase in failures is in tracking brackets, with related losses projected to increase by 25% by 2025, accounting for approximately 14% of total power losses. This trend also reflects the increasingly widespread application of tracking bracket technology in the photovoltaic industry to increase power generation.

Raptor Maps stated, "While data shows a decrease in inverter-related losses, we have observed an upward trend in power losses occurring at multiple points. Currently, issues with strings, combiner boxes, and tracking brackets are having a 25% greater impact on overall power generation compared to last year. This shift from centralized to distributed power losses highlights the importance of high-frequency data monitoring—proactively identifying these anomalies is crucial to preventing the accumulation of larger power generation gaps." Unsurprisingly, the Raptor Maps report shows that regular inspections of photovoltaic power plants can significantly reduce power losses. Data indicates that power plants inspected once a year experience an average power loss of nearly 7%, while those inspected five times a year suffer only about 3% power loss.