We are offering solar pv modules (3wp-300wp). cellscells will be monocrystalline, polycrystalline, ribbon silicon, thin-film, or even multiple silicon layers, such as with sanyos hit module. Electrical characteristics, efficiencies, and appearance vary by cell type (see a peek inside pv, hp132). Modules can have variable numbers of cells (usually between 36 and 108)with each crystalline cell operating at around 0.5 vdc, wired in series or series-parallel configurations. For example, a 72-cell module with all cells in series will operate at a voltage of about 36 volts. But a72-cellmodule with two series strings of 36 cells paralleled will operate at about 18 v, perfect for charging a12 v batteries.