Photovoltaic solar panels (PV) come in many different forms. Do you know your polycrystalline from your mono, or thin film from hybrid?
The answer, unless you are in the industry is in all likelihood no.
There are a number of different types of solar photovoltaic systems available. Each do the same thing; convert solar radiation into electricity, but have different characteristics and prices.
Monocrystalline Silicon PV
To produce monocrystalline silicon a single crystal of silicon is grown and then cut into thin slices. The edges are cut off to give a hexagonal shape so more can be fitted onto the module. These PV cells have efficiencies of 13-17% and are the most efficient type of the three types of silicon PV cell. However, they require more time and energy to produce than polycrystalline silicon PV cells, and are therefore slightly more expensive.
Polycrystalline Silicon PV
Polycrystalline silicon is produced from a number of smaller silicon crystals. They are cooled from a molten and highly pure molten silicon, using a casting process. It sets as an irregular poly- or multi-crystal form. The square silicon block is then cut into slices. The typical blue appearance is due to the application of an anti-reflective layer. Mass-produced polycrystalline PV cell modules have an efficiency of 11-15%.
Amorphous Silicon (thin film) PV
Amorphous silicon is non-crystalline silicon. These PV cells are made by depositing a thin film of silicon in a gas state onto a material such as glass. These are the cheapest (less material is used in their production) and least efficient (between 6-8%) type. This type of cell is suitable for high temperatures and is used in hotter countries where large areas can be covered. Due to low generation density this type is not currently suitable for residential developments.
Hybrid PV
Hybrid photovoltaic cells are classified as PV cells that use two different types of PV technology. The Hybrid PV cell shown here is made by Sanyo and comprises a monocrystalline PV cell covered by an ultra-thin Amorphous silicon PV layer. The advantage of these types of cells are that they perform well at high temperatures and maintain higher efficiencies (18%+) than conventional silicon PV cells. However, this efficiency comes at a cost premium.
Decision time
So now you know the different types, which is best for you?
In summary there is a direct relation to PV panel efficiency and cost. The higher the efficiency the higher the energy density or kWp/m². This is important if you have a limited space available to fit PV panels into.
You may consider the hybrid Sanyo option if roof space is an issue or whilst the most expensive, want the most efficient panel available.
The polycrystalline option may match your requirements if you have a large roof, your system is over 4kWp or you want to maximise the return on your investment.
The monocrystalline option can be seen as somewhere in-between the previous two, reasonably efficiency with a reasonable price tag.
