Solar’s Costliest Blind Spot May Be Hiding in Plain Sight

Solar power has become one of the fastest-growing sources of new electricity capacity worldwide. The International Energy Agency reports that global solar photovoltaic capacity additions surpassed 600 gigawatts in 2025, bringing cumulative capacity to approximately 2,800 gigawatts. As investment accelerates, an important question confronts the businesses financing this expansion: how can owners be certain their installations are delivering the performance they were promised?

This question is important because solar installations are long-term financial commitments. Owners base their expectations on projected electricity generation, yet those projections can lose their value if equipment gradually deteriorates or faults remain undetected. A system may continue producing power while generating less than expected, leaving its owner to absorb the difference in revenue.

Miguel de Anquin believes the industry has placed too much confidence in the information available through conventional monitoring. In his experience developing and constructing commercial solar projects, some of the most costly problems are difficult to spot through routine operational reports. Dust accumulating on panels, damaged cells and wiring faults can affect output without necessarily triggering the warnings owners expect to see.

"People look at the monitoring system and see that everything is working, so they assume the installation is fine," Miguel explains. "But the system can be generating electricity and still have problems that are reducing its output. You have to understand what is happening physically across the panels, because the dashboard cannot tell you everything."

Miguel, founder of kWh Data, has spent more than two decades working in solar development and construction. Together with his son, Santi, whose experience includes solar analysis, energy economics, enterprise software and FAA-licensed drone operations, the team focuses on identifying performance issues that can escape conventional monitoring. They combine practical knowledge of how solar installations are built with tools designed to examine their condition.

One of the most common problems, Miguel explains, is soiling: the accumulation of dust, dirt, and other material on panel surfaces. The extent of the problem depends on the installation's surroundings. A commercial building near a busy road may collect airborne dust, while agricultural sites can experience accumulation associated with nearby fieldwork. Bird droppings and vegetation can create additional obstructions.

"Sometimes you look at a panel and see a little bit of dust, but you cannot tell just by looking at it how much that is affecting generation," Santi explains. "You also don't want to spend thousands of dollars washing panels if you don't need to. You need to know whether the problem is significant enough to justify the expense."

Other faults can be harder to resolve. Miguel points to manufacturing defects that cause hotspots within solar modules, as well as wiring problems that can affect connected panels. Some defects may fall under a manufacturer's warranty, making it important for owners to establish what has failed and whether the evidence supports a claim. His concern is that conventional maintenance teams, often working primarily from monitoring reports, may not have the tools to identify every such problem.

A case study published by kWh Data illustrates the financial stakes. The company examined a 1-megawatt rooftop installation near Sacramento, California, containing 2,506 solar modules. According to its report, the system was underperforming by approximately 18%, representing an estimated $37,000 in annual lost revenue despite its monitoring portal showing no significant warnings. An aerial thermal scan identified 178 anomalies, including extensive soiling and electrical faults.

Following targeted repairs, the company recorded a 34% increase in generation across three-day periods before and after the intervention. It estimated annual cash-flow recovery of approximately $50,000, although longer-term, weather-normalised data is needed to establish sustained gains.

The inspection process uses drones equipped with thermal imaging technology to identify temperature variations across solar modules. Software analysis helps locate anomalies, giving technicians a more precise starting point for investigating suspected faults. Miguel compares the process to a medical checkup, in which establishing a baseline makes it easier to recognise changes over time.

"It's like going to the doctor every year," Santi explains. "You want to know how the system looks today, and then you want to compare it with the previous year. If things are getting worse, you can identify the problem and take action before you lose more production."

The approach also has implications for investors buying and selling solar portfolios. Miguel argues that an independent inspection can help buyers understand the physical condition of an asset before committing capital, while giving sellers evidence to support their assessment of the installation. Owners can also use the findings to investigate underperformance and determine whether further maintenance or warranty action is justified.

As solar investments mature, the ability to verify performance could become important to protecting their financial value. The team's argument lies in the idea that owners need to know what their systems are actually producing, not simply whether they appear operational. Building solar infrastructure creates the opportunity to generate returns. Understanding what happens after installation might determine how reliably those returns can be sustained.