The influence of shadows

Solar energy is one of the cleanest and most sustainable sources in the world. However, despite its many benefits, its efficiency can be compromised by a sometimes overlooked detail: shadows. From a nearby tree to a rooftop antenna, any object that casts a shadow on a solar panel can significantly impact its performance.

Why Do Shadows Have Such an Impact?

Solar panels are made up of many photovoltaic cells connected to each other. This means that the energy produced by each cell depends on the others: if one cell is affected by shade, the performance of the entire panel (and sometimes an entire string of panels) can decrease considerably.

Types of Shadows and Their Effects

1. Partial or temporary shadows: Trees moving in the wind, birds, or even clouds passing by occasionally. Although they may seem harmless, they can cause temporary drops in energy production.

2. Fixed shadows: Chimneys, antennas, nearby walls, or other structures. These are more problematic because their effect is constant during certain hours of the day.

3. Dirt and small objects: Dry leaves, snow, or even bird droppings also act as shadows, especially if they accumulate on the same cells constantly.

How Much Can a Shade Affect You?

The impact can be greater than you imagine. A shade covering just 10% of a panel can reduce its efficiency by up to 50% or more, depending on the system design. In series-connected systems, a single shaded cell can act as a bottleneck for the entire system.

Solutions and Prevention

Fortunately, there are several ways to mitigate the effect of shadows:

• Smart system design: A thorough pre-site analysis (including a shadow study) by a qualified energy consultant allows panels to be strategically placed, away from obstacles.

• Microinverters and power optimizers: Unlike central inverters, these devices allow each panel to operate independently, reducing the impact of shadows on the entire system.

• Regular maintenance: Cleaning the panels and ensuring there are no objects that interfere with direct sunlight helps maintain their performance.

• Use of panels with diode bypasses technology: These panels allow current to flow through alternative paths if one part of the panel is blocked, but more on that later.

Say yes to green energy, but wisely!