Shadows on solar systems: How power optimizers can help

Power optimizers play a key role in solar systems operating under difficult conditions, such as shade management and photovoltaics. Unlike conventional wiring, where a shaded module severely impairs the performance of the entire string, SolarEdge power optimizers intervene in a targeted manner. They control each individual module separately and prevent low-performance or shaded modules from slowing down the entire system. This optimizes the energy yield of the unshaded modules and keeps the overall performance of the system at a high level—even in unfavorable lighting conditions.

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Why shadows are problematic

Power loss: As soon as one module in a series connection is shaded, the efficiency of the entire photovoltaic system suffers. The total output always depends on the weakest link – so if one module loses power due to shading, it drags all the others down with it.

Overheating: Shaded cells tend to develop so-called “hot spots.” This overheating can significantly shorten the service life of the modules and, in the worst case, lead to complete failure.

Enormous Losses: Even minor shading can have a serious impact on energy yield. Losses of up to 90% are possible – which makes even the smallest amount of shading a serious risk to the profitability of your solar system.

How power optimizers work

Each of these optimizers is located directly on its own solar module and works independently, without being affected by less powerful neighbors. Essentially, the optimizer controls the individual module so that it always remains as close as possible to its maximum power point (i.e., the optimal operating point) – and this works even when other modules are shaded or otherwise not performing ideally. Particularly valuable: fluctuations or drops in performance in one module no longer have a negative impact on the overall performance of the system. The optimizer takes over the “isolation” and thus ensures that the full system performance is maintained as best as possible. This ultimately makes the overall system significantly more reliable and efficient.

Advantages of power optimizers

• Significantly increased energy yield: Especially in cases of regular shading, optimizers can produce up to 25% more energy. This means that your system operates much more economically.
• Optimized module service life: Overheating and hot spots are minimized. The result? The solar modules remain efficient for longer – good for your bottom line and investment security.
• Maximum efficiency: Optimizers exploit the full potential of each individual module. This allows you to get the most out of your PV system in partial shading conditions and increase its long-term efficiency.

When is it worth using them?

Regular shading—i.e., when elements such as trees, chimneys, or neighboring buildings constantly cast shadows—makes power optimizers absolutely worthwhile.

Different conditions also arise when modules are oriented or tilted differently, meaning that not every module in the same string receives the same amount of sunlight. In this case, optimizers can help to get the most out of the system.

Of course, the devices are quite expensive. An investment pays off especially if there is frequent and pronounced shading. For systems without significant shading, the added value is usually low, partly because optimizers consume some electricity for their own operation. You really have to weigh up whether it pays off in each individual case.

This article is intended for informational purposes only and does not constitute a binding offer or professional advice.