Poly-Crystalline panels are some of the original solar products. They are still used today, but should only be reserved for large scale utility grid solar, commercial, or industrial solar to reduce the cost of a larger scale project. The prefix Poly is used because many pieces of silicone are melted together to form one large piece. Poly-Crystalline has a lower energy yield because of having many pieces melted together to form one piece. Poly-Crystalline panels produce on average in between 13 to 16% less in the same amount of space than Mono-Crystalline panels do. This means Poly-Crystalline panels need a much larger size to produce the same amount of energy and require a much larger amount of roof space. That means you are using much more space which may not be an option if you lack proper roof space, and many more panels to achieve the same amount of production. Poly-Crystalline panels are less resistant to heat, so have a faster degradation time, and will have to be replaced in your lifetime.
Mono-Crystalline is today's panels. The prefix Mono is used because its one piece Silicone used rather than many melted together. Because only one piece is used it creates an energy yield 13 to 16% higher than a Poly panel and much better overall Electricity Production. They are more resistant to heat which means they have a much slower degradation period. This also means that on top of the longer life span that they produce at higher rates of efficiency for much longer. . Because of their ability to be much more efficient and yield so much more electricity they are smaller panels. This maximizes the available space on your roof, and maximizes output and productivity with a much smaller area.
PERC stands for Passivated Emitter and Rear Cell. PERC was invented in Australia in 1980 but has only started taking off in the solar industry in the last three years. Solar panel cells can be divided into two categories:
Thanks to PERC solar cells we can now get affordable panels at higher wattage. LG Neon are the PERC N Type. All that means are that these type of Mono-Crystalline panels have a special outer surface and a reflective layer beneath it on the surface, and another layer on the bottom with power reflectors and local contacts that have another layer of aluminum behind them. Essentially the layers cause a ray of light to bounce around a beam of light inside of panel to get the most energy from each ray. This is the most cost effective, and energy efficient way to harness the most energy for residential roof-top solar at the highest wattage's, and using the least amount of space.