This Is How Solar Panels Actually Work

You already know that solar panels turn sunlight into electricity. But how? It almost seems like magic. Well, it’s magical, but while it's not an illusion, the science behind it—the photovoltaic effect—is fascinating. Considering the rising costs of heating as well as the effects of climate change, it’s a good time to invest in solar panels for your house. Not only are you helping by creating clean energy for decades to come, you’ll also shave off a good chunk of your monthly bills. 

What is the solar panel system made of?

First, let’s look at the solar panel itself. There are the solar cells, which are made out of silicon—they're the main element that turns sunlight into electricity. Then, around it, you’ll find an insulating shell, made out of glass or polymer. A metal frame holds everything together, protecting the tech from outside elements. There’s also a junction box that protects the diodes, the wiring, and the electrical components. Lastly, the panels use MC5 connectors, which connect all the solar panels together to create a singular array.

The solar power system is made up of many different components other than the panel itself. These components do the job of converting, storing, or sharing the electricity that is generated by the solar panel. Here are some of the major components you’ll find:

• Inverter: The inverter is the most critical part of any solar energy system. By default, the solar cells generate direct current, or DC electricity, but most household appliances operate on alternating current, AC. The inverter coverts the DC electricity to AC power so it can be used to run your lights, fans, or your refrigerator. 

• DC optimizers and string inverters: An optimizer helps each panel run at maximum power point tracking, independently. MPPT, as it’s called, is then fed into the AD inverter process.

• Microinverters: These devices track maximum power point, and invert DC to AC directly on the panel. They can help remove the need for a central inverter. 

• Rapid shutdown device: This is a safety mechanism that ensures a safe shutdown of the entire solar power system.

• Telemetry hub: This is the part that monitors the entire system and shows the data to users, usually through a digital panel.

• Battery: This is not required if you’re building a grid-based solar panel system, where the generated energy directly feeds into your local area grid, and you earn credits for the energy you supply. But if you’re building an off-the-grid system, or if your setup is in a remote area, you’ll need a battery to save and use the generated electricity. 

How the photovoltaic effect in solar charging works

As we mentioned above, solar chargers work based on the photovoltaic effect. Before we talk about that, however, you should first understand the photoelectric effect. 

The photoelectric effect is the phenomenon where electrons are ejected from the surface of a material when light shines on it. This happens because the light photons' energy is absorbed by the electrons, giving them enough energy to overcome the binding energy that holds them to the material. The ejected electrons are called photoelectrons. As the free electrons move, they generate current and voltage.

The photovoltaic effect is similar, but here, photons from the sunlight are absorbed by the solar cell instead. The photons then energize the electrons that are inside the solar cell material. This removes them from their atomic bonds, and they become free. The solar cells have a PN junction composed of semiconductor materials that direct the flow of the free electrons, and that’s how the electricity is generated. 

Should you go off-grid?

Simply getting a solar-powered system does not mean your house is off-grid, and you’ll be happy to know it doesn’t have to be, either. You can continue to stay in the grid, connected to the local electricity provider as a backup, while running your own solar-powered station. 

Without a battery, the electricity that’s not used by your house will automatically end up in the grid. How this works might depend on local laws, but usually, there’s a monitoring device to calculate the units of electricity generated, and you get credits for selling your share to the grid. This route is cheaper, because you don’t need to buy an expensive battery to add to your system. 

Should you choose to, it will be connected directly to the solar power system, where the electricity will be transferred and stored. Then, when you need to run an appliance, the inverter will convert the energy stored in the battery to AC power. 

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