Everyone knows that solar panels capture sunlight and turn it into clean, more affordable electricity that you can use in your business.
But how are solar photovoltaic (PV) panels made, and how exactly do they work?
What are solar panels made of?
Very few ingredients go into the making of a solar PV panel. But that doesn’t mean all panels are created equal.
The key components of a panel are silicon, metal (usually aluminium), glass, and some wiring. The most important of these are the silicon cells.
Silicon is essential for creating photovoltaic energy. This is because silicon is a non-metal compound that has conductive properties.
How do solar panels work?
Solar PV systems receive energy from sunlight (not from the sun’s heat). Sunlight is composed of photon particles, which release electrons when they hit a panel’s silicon cells.
Once released, the electrons dart around the silicon cells that are interconnected to form a circuit in the panel. Assisted by an electric field, the movement of the electrons generates energy.
Once the electricity has started to flow, the other parts of the solar panel come into play.
The metal casing and wiring allow the solar cell’s electrons to be released from the cell and channelled along the solar system’s ‘string’, which links the individual panels in the solar power array.
The electrons are channelled to the system’s solar inverter. The inverter then converts the low-voltage DC (direct current) generated from the panels into a higher-voltage AC (alternating current) – which is the form of electricity that most used in buildings.
Once the electricity has passed through the inverter, the power can either be stored in a solar battery storage system for direct use onsite or it can be fed into the grid (if this has been approved).
Are there different types of solar panels?
Solar panels come different sizes and styles to suit a variety of uses. Generally, a panel for a commercial-scale system is larger and uses more cells than a panel for residential use.
The most important difference between solar panels is the form of silicon they use.
Silicon comes in a number of different cell structures: single cell (monocrystalline), polycrystalline or amorphous forms.
Monocrystalline solar panels are produced by cutting individual wafers of silicon from one large silicon block. These individual silicon wafers can then be attached onto a solar panel.
Monocrystalline silicon cells are more efficient than polycrystalline or amorphous solar cells, but they are also the most expensive. This is because the processes needed to cut the individual monocrystalline wafers are more labour-intensive.
Polycrystalline solar cells are also silicon cells. But the cells are produced by melting multiple silicon crystals together. Many silicon molecules are melted and then re-fused into the panel itself. Polycrystalline cells are less efficient than monocrystalline cells, but they are also less expensive.
Amorphous silicon cells are non-crystalline. Because of this they are attached to a substrate like glass, plastic or metal and can be used to create flexible and very thin film solar panels. Though very versatile, amorphous solar cells are currently very inefficient compared to mono or polycrystalline cells.
What are the parts of a solar panel?
In addition to the solar cells themselves, a standard solar panel includes a glass casing at the front of the panel, which adds durability and protects the silicon cells.
Under this, the panel has a casing for insulation and a protective back sheet, which helps to limit heat dissipation and humidity inside the panel. The insulation is particularly important because if it gets too hot or humid inside the panel, the efficiency of the panel decreases and so does the amount of energy it generates.
Regardless of the particular type of silicon cell that is being used, manufacturers finished the process of making a solar panel by adding an anti-reflective coating to the cells, housing the entire system in a metal and glass casing and connecting the electrical systems.