Solar Cells with Built-in Smart Electronics on the Back

This patent describes a solar cell design that integrates electronic components, like a bypass switch, directly onto the back of the cell to improve performance, especially when parts of the cell are shaded.

What it covers

The patent describes a "back contact solar cell" (Claim 1), which means all the electrical connections are on the back, leaving the front clear to capture more light. It uses two layers of "interdigitated metallization" (Claim 1) on the back. The first layer makes contact with the semiconductor material, while the second layer, placed over a "backplane," collects the power using "base and emitter busbars." Crucially, an "electronic component" with a "bypass switch" (Claim 1) is directly connected to these busbars. This bypass switch automatically reroutes current around a shaded or faulty part of the cell, preventing it from dragging down the performance of the entire solar panel. For example, if a leaf shades one part of the cell, the bypass switch activates, allowing the rest of the cell to continue producing power efficiently.

What it doesn't cover

• —Does not cover solar cells where the electrical contacts are on the front side.
• —Does not cover solar cells without an integrated electronic component having a bypass switch.
• —Does not cover designs that use only one layer of interdigitated metallization for power extraction.
• —Does not cover electronic components that are not electrically connected to at least a base busbar and an emitter busbar.
• —Does not cover solar cells where the electronic component is located off the cell or module, rather than integrated.

The clever bit

The clever bit is placing sophisticated electronic components, like a bypass switch, directly onto the back of a back-contact solar cell, specifically connecting to the "base and emitter busbars" of the "second interdigitated metallization." This integration allows for finer-grained control and optimization at the individual cell level, which was previously handled at the module or string level, improving overall system resilience to shading.

Why it matters

Integrating smart electronics directly into solar cells or modules helps solve a major problem in solar power: shading. When even a small part of a traditional solar panel is shaded, the entire panel's output can drop significantly. By including bypass switches and potentially power optimizers (Claim 7) at the cell level, this technology allows solar panels to produce more electricity, even under less-than-ideal conditions, making solar energy systems more reliable and efficient.

Real-world examples

• 1.Smart solar modules with integrated power optimizers
• 2.Per-module or per-cell bypass diode implementations
• 3.Solar panels designed for partial shading tolerance
• 4.Microinverter-equipped solar panels