PV cells are use semiconductors to turn sun radiation into electricity and are usually made of a special photovoltaic substance comprising cadmium telluride, mono and poly crystalline silicon, copper indium sulphide and amorphous silicon.
At this time there are many photo voltaic material in the solar market:
- Mono crystalline Silicon(Si)
- Poly crystalline Silicon (Si)
- Amorphous Silicon (a:Si)
- Cadmium Teluride (CdTe)
- Copper indium Gallium Selenide/Sulphide (CIGS)
When you connect multiple PV cells they will form a solar panel.
The PV panels (mono and poly) are rated according to the peak power they produce in watts DC.
Mono vs Poly solar panel
PV panel's have an efficacy depending on the physical characteristics of the semiconductor used. The commercially produced Mono crystalline Silicon PV panels could be as efficient as up to 18%.The Thin Film PV panels on the other hand would be only about 8-10% efficient.
Mono Crystalline Silicon PV Panels - max efficiency ~25.0%
Poly crystalline Silicon PV Panels -max efficiency ~20.5%
Solar panel efficiency can be compensate by bigger surface area. (5%)
100w Poly crystalline Silicon PV panel: dimensions: 1195 mm x 541 mm (0.64 sq meter), with an efficency of 17.80%
100w Mono crystalline Silicon PV panel: dimensions: 1015 mm x 670 mm (0.68 sq meter), with an efficency of 16.50%
Monocrystalline cells have a higher efficiency than polycrystalline cells due to the structure being made from one large crystal as opposed to many small ones.
The biggest difference for home user, between mono and poly solar panels is the panel surface area, at the same power (DC watts), poly panels are bigger, but they are cheaper.
But remember, panel efficiency decreases over time, for exeample in the first ten years are lost about 10% of power, and in the next 10 years another 10%, totally 20% from the initial power of the PV panel.
Today, Photovoltaic cells and panels are used in over a hundred of countries and trends indicate that this industry is due for a large growth spurt in the coming years.