Solar systems to generate electricity in homes are becoming increasingly popular with homeowners, not just for the financial benefits but also as the focus intensifies on the desire for increased use of renewable energy sources. However, many people are still unfamiliar with how solar systems work, particularly how solar panels can transform light from the sun or any other source into usable domestic electricity.
In this beginner’s guide, we will explain the basic principles behind solar panels and how they can be used to produce electricity for homes. Fear not; we will not make it so technical that you would need a degree in solar energy or electrical engineering to understand it.
What Are Solar Panels?
Let us start with the absolute basics, and that is answering the question, “What are solar panels?” just in case anyone reading is not aware of them. Solar panels are devices within a solar power system that convert sunlight into electricity, and they can be used for both residential and commercial properties. They are made up of numerous photovoltaic (PV) cells, which comprise mainly silicon but also some other materials.
When sunlight hits these PV cells, it causes electrons to move, creating an electrical current. At this stage, the electricity created is direct current (DC) akin to the electricity supplied by the battery and alternator within your car, so it has to be converted into alternating current (AC) for use in domestic properties.
How Do Solar Panels Work?
The whole process of converting sunlight into electricity has three functions which are collection, storage and usage and these require four components to be present, namely solar panels, charge controllers, inverters and storage batteries. Solar panels act as collectors, and they work by converting sunlight into direct current (DC) electricity.
The PV cells in the panels absorb sunlight, which causes electrons to be released from atoms. These freed electrons then flow through the PV cell and are collected by metal contacts on the top and bottom of the cell. This creates a direct current of electricity. However, as most homes and businesses run on alternating current (AC) electricity, the solar panels are therefore connected to an inverter.
The inverter converts the DC electricity from the solar panels into AC electricity that can be used to power appliances and devices within homes. The role the battery plays in the whole process is to store the excess electricity generated by the solar panels until it is required. The charge controllers help regulate the current flowing to the batteries and the inverter.
Different Types Of Solar Panels
Three main types of solar panels can be installed on homes, with the main differential being the solar cells within the solar panel which convert light to electricity. The solar cell types influence the solar panel’s construction, efficiency, and cost. The three main solar cell types are monocrystalline, polycrystalline, and thin film, and here is how they differ.
Monocrystalline Solar Panels: These are the most efficient solar panels that can be installed but they are also the most expensive. They are constructed using a single element of silicon which allows these solar panels to convert sunlight into electricity more efficiently due to the cell structure having minimal imperfections. This efficiency is why monocrystalline solar panels are the type most used for residential solar system installations.
Polycrystalline Solar Panels: These solar panels are made from multiple silicon crystals. They are less expensive than monocrystalline panels but are also less efficient. Using multiple silicon fragments makes the manufacturing process simpler and less costly to manufacturers, which is why polycrystalline solar panels are cheaper and often an option for homeowners that want a solar power system installed but have a limited budget.
Thin-Film Solar Panels: These solar panels consist of a thin layer of photovoltaic material that is deposited onto another material, such as metal, glass, or plastic. They are less expensive than crystalline panels but also less efficient. These solar panels are rarely used for domestic installations and are more likely to be found on large solar farms.
Solar Panels Lifespan
As they have no moving parts, there is very little within a solar panel that ‘wears out’, although they do have a finite lifespan. This is usually around 25 to 30 years, assuming they are maintained properly throughout that time such as cleaning and removing debris. Even after this time, a solar panel will still be able to convert sunlight into electricity, however, it will be less efficient and below a level that makes it viable for use for domestic electricity generation.