Large Solar Panels

The large solar panel category includes panels (or modules) from 50 Watts and up. This category includes modules which are great for smaller 12V battery systems, like 80 Watt and 135 Watt 12 Volt modules, specialized products for industrial use such as 80W 24V modules, as well as larger cutting edge 250 Watt modules for larger systems of all types, including home solar power systems.

In the past, 12 Volts was the standard nominal output for most panels, since battery charging was a common application. A 12 Volt nominal panel actually puts out more than 12 Volts, so the voltage is sufficient to charge a 12V battery. The real output of solar panels can be seen on the spec sheets, by looking at Vmpp, which is the voltage they operate at optimally. A 12V panel will operate optimally at around 16 or 17 Volts. This does vary significantly with temperature, which is one reason the rated voltage is quite a bit higher than the nominal voltage.

As modules became bigger, 24 Volts became a common nominal voltage, and it still is used today. These modules will of course work well to charge a 24V battery, and they are commonly wired in series to charge 48V batteries, or for higher voltage circuits to feed grid tie inverters. To make the panel voltage higher requires putting more of the solar cells in series - there are usually 36 cells in series in a 12V panel, and 72 cells in series in a 24V panel.

Over time, the solar cells themselves have become bigger and more powerful as well. Common sizes are 4", 5", and most recently, 6" (or 156mm). With the newer 6" cells, a 60 cell module has become common, since a 72 cell panel with 6" cells is a bit large for a person to handle. Some people do refer to 60 cell panels as 24 Volt panels, but we feel it is more correct to call these 60 cell panels 20 Volt nominal, to distinguish them from the 72 cell panels.

Quantity discount pricing available on many items. Complete systems are priced with best quantity discounts, regardless of system size.