The panels themselves come in various forms:
- Crystalline solar panels - As the name suggests these types of panels are made from crystalline silicon. They can be either monocrystalline or poly- or multi-crystalline. As a rule of thumb monocrystalline versions are more efficient (about 15-20%) but more expensive than their alternatives (tend to be 13-16% efficient) but advancements are closing the gap between them over time.
- Thin-film solar panels - These types of panels consist of a series of films that absorb light in different parts of the EM spectrum. They tend to be made from amorphous silicon (aSi), cadmium telluride (CdTe), cadmium sulfide (CdS), and copper indium (gallium) diselenide. This type of panel is ideal for applications as flexible films over existing surfaces or for integration within building materials like roofing tiles.
These types of plant generate electricity that is then, usually, directly fed into the national grid.
PV panel array at Marche, Italy. Source: CA' Marinello 1/Flickr
These kinds of power plant tend to have the following basic components:-
- Solar panels that convert sunlight into useful electricity. They tend to generate DC current with voltages up to 1500 v;
- These plants need investors to transform the DC into AC
- They usually have some form of a monitoring system to control and manage the plant and;
- They are directly connected to an external power grid of some kind.
- If the plant generates in excess of 500 kW they will usually also employ step-up transformers.