Wait… What Does 5 Busbars Even Mean for Solar Panels?
SolarWorld has started shipping their new, higher efficient 5 busbar solar panels. What does that mean, and how does that affect you?
The busbars are the metal lines you see going down the individual squares, or cells, of the solar panel. They are the wires that connect each cell to the other, allowing the current to flow. Since each cell is generally just over a half a volt, the bus bars wire them together in series to create the higher voltages needed to be a usable solar panel. For a typical 60 cell, 20V nominal solar panel, that equals around 32Vmp (maximum power point voltage).
The older models of the SolarWorld Sunmodule® Plus have three bus bars, as seen in this picture with the 3 lines on each column of solar cells.
The newer models have 5 busbars connecting the cells in series. You can see the picture has five lines down each column of solar cells.
What Is the Benefit of More Busbars on SolarWorld’s Solar Panels?
Additional busbars creates lower resistance between cells. Ohms Law tells us that as resistance (ohms, R, or Ω) go down, the current (amps) goes up. And when current goes up for the same voltage, power (which is volts times amps) goes up. Think of it as adding two more lanes to the highway, more cars can pass through at one time.
The result of the additional busbars is that the solar panels are about 2% more efficient. This means that they can output 2% more power in the same size solar panel. As their manufacturing process gets more and more efficient, they can increase the wattage of their standard 60 cell solar panels.
Hard to See the Difference – Unless they’re Side-by-Side
The change to the design does not change the color of the solar cells, or the size of the solar panels. However, when mounted side by side, the additional busbars may be noticeable. If you are adding additional solar panels to an existing array that is in a visible location, you may want to match the models to keep the thin lines consistent.
If you are ordering online, be sure to note if you need the older 3 busbar panels, they are available by request while supplies last. If you are installing a new system, or adding onto an existing solar system that is not in a high visibility location, using the new 5 busbar models will get you a higher efficiency solution.