What is a Solar Panel and How Does it Work?
Solar panels, aka PV [photovoltaic] panels, are composed of photovoltaic cells mounted in a frame. These are used to capture sunlight as energy and generate direct current [DC] electricity. A collection of these PV modules is called a PV panel. A collection of PV panels for any given project is termed a PV array.
DIAGRAM OF A PV PANEL
There are essentially two types of PV panels used today:
- Polycrystalline PV panels, and
- Monocrystalline PV panels
Polycrystalline, or multicrystalline solar panels, are solar panels that consist of several crystals of silicon in a single PV cell. There is no difference between polycrystalline and multicrystalline panels.
A monocrystalline solar panel is a solar panel comprising monocrystalline solar cells. These cells are made from a cylindrical silicon ingot grown from a single crystal of silicon of high purity in the same way as a semiconductor. The cylindrical ingot is sliced into wafers, forming cells.
There are many variants of polycrystalline and monocrystalline panels to choose from and many different companies producing them. The key difference between the two is price-related. Many think that one panel type is more efficient than the other, but the choice of panel is mostly based on the look and design of the panel.
Monocrystalline panels offer a sleek black, styled look and finish which resonates with upmarket estates and homeowners. The price point is premium, normally a good 25% more than a polycrystalline panel. Efficiency rates are roughly the same, as both panel types can reach approximately 22% efficiency.
Polycrystalline is blue and has been widely adopted before its mono cousin. It is the cheaper alternative and good value for money. Used predominantly in residential and commercial capacities.
Credit: Energy Sage
Solar panel sizes in watts
Solar panels are measured in watts and frame size. Watts is the electricity potential it can generate on a good sunny day, and frame size is used to figure out how many you can fit on your roof. Taking watts and frame size into account, a qualified installer can calculate how many panels you need for your power requirements.
10 years ago, a 200w polycrystalline solar panel was top of the range. Now we have solar panels of between 600w – 800w in both polycrystalline and monocrystalline options.
Fun fact: Did you know that there is around about 1,3kw – 1,5kw of solar energy per square meter all over the world?
When it comes to solar panels, there are more things to consider when choosing a panel that is not covered in this basic introduction. Other factors to consider, which will be covered in more detail, are the following:
- Roof position and roof type
- Weather concerns
- Total power needs
- Additional components such as inverter and batteries
- Type of system, such as grid-tied or off-grid
Solar panels are only designed to capture sunlight and make DC electricity ready. Additional technologies, such as solar inverters and/or solar batteries, are also required to complete the total system.
Even though solar panels make available energy from the sun, they are still very inefficient. This means that the sizing of your PV array is very important. It is recommended you use an accredited solar installer to work out the correct sizing and load calculations.
Read more on solar systems
Thank you for reading this article. If you feel we have left out any important information or would like to contribute to this site and content, please get in touch with us by leaving a comment or emailing us directly.