Solar panel modules come in a variety of 'designs'. The untrained eyes may be befooled into thinking that they are for style, but for what they truly are, the variations in designs are often a matter of the technology used in their manufacture of the panels than of mere aesthetics. New trends and innovation in the solar module industry quickly follow the latest ones in rapid succession, often times displacing them. The reason being that manufacturers are constantly pushing back the limits of efficiency of their module offerings. In fact, all the top manufacturers have ceased offering panels manufactured from the traditional technologies. There is significant competition between manufacturers, especially the premium brands, in this respect. The efficiency of a solar panel is how well it performs its function of converting sunlight into electricity. The latest solar panel technologies - or designs -, though expectedly far more expensive, come with the highest efficiency ratings.
The traditional technology used in the manufacture are the polycrystalline and monocrystalline technologies. Between the two, monocrystalline is the superior cell technology. Monocrystalline cells are more efficient because they are cut from a single pure crystal ingot. However, because they cost more to manufacture, polycrystalline panels became more popular even though they are inferior to their monocrystalline counterpart. With the drop in manufacturing costs, many manufacturers now use the monocrystalline technology. In fact, even though poly cells are still widely used and very reliable, the top brands have altogether stopped issuing polycrystalline panels and many mid-grade manufacturers are following suit.
By and large, these new solar cell technologies are upgrades on the traditional monocrystalline module technologies. They are listed below in ascending order of efficiency:
PERC - Passivated Emitter Rear Cell
Multi Busbar Cells
Dual Glass Panels - Frameless Double Glass
HJT - Heterojunction Cells
IBC - Interdigitated Back Contact Cells