Honduras car-mounted double-glass photovoltaic modules

ABSTRACT: Double-glass modules provide a heavy-duty solution for harsh environments with high temperature, high humidity or high UV conditions that usually impact the reliability of traditional solar modules with backsheet material.

The double glass module design offers not only much higher reliability and longer durability but also significant Balance of System cost savings by eliminating the aluminum frame of conventional modules and frame-grounding requirements. The application of double-glass modules covers multiple markets including utility, residential and commercial.

National electrical codes in most countries dictate that the PV module frame must be electrically grounded. This grounding interconnection results in a potential difference (voltage) between the grounded frames and the cells in the PV modules, which may lead to a module degradation called Potential Induced Degradation (PID).

Glass-Glass module designs are an old technology that utilises a glass layer on the back of modules in place of traditional polymer backsheets. They were heavy and expensive allowing for the lighter polymer backsheets to gain the majority of the market share at the time.

A frameless double-glass module and a traditional PV module with a 3.2mm glass with an aluminum frame were both qualified to withstand heavy accumulations of snow and ice under a high pressure of 5400Pa up to 6700Pa. modules are connected electrically in series until a maximum string voltage of 600 volt or 1,000 volt is achieved.

The weight of glass-glass modules are still an issue, with current designs using 2 mm thick glass on each side for framed modules, the weight is about 22 kg, while 2.5 mm on each side will increase the module's weight to 23 kg. Compared to traditional glass-foil modules, which are about 18 kg, this is a 20% increase in weight.