How Do Solar Panels Work? The Homeowner’s Guide to Understanding Solar Power

Allie Ogletree
Written by Allie Ogletree
Updated September 8, 2022
A house with its roof covered with solar panels
Photo: schmidt-z / E+ / Getty Images

Highlights

  • Solar panels use silicon to capture sunlight.

  • Inverters convert solar energy from DC to AC.

  • Your breaker box sends the AC energy throughout your home.

  • Receive a reimbursement by sending excess energy to the grid.

  • You can store excess energy in a backup battery.

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Unpredictable weather can cause power outages that ruin dinner or cut the TV out mid-show—but it doesn’t have to be this way. Solar power generation offers an alternative that’ll make your home less energy dependent—but how do solar panels work? 

Before you hire a local solar installation company, here’s everything you need to know about what solar panels do and how they work. 

How Does Solar Energy Work?

Before you make the leap to panels, you might be curious to learn more about solar power generation. Solar energy is a type of renewable energy, similar to wind or geothermal. It is not depleted when used like fossil fuels, making it a sustainable energy source. 

Like geothermal energy, solar energy also doesn’t produce greenhouse gases or pollution, making it far cleaner than traditional energy sources. This form of renewable energy works through sunlight absorption, converting that energy into power, and transferring that power into usable electricity.

What Do Solar Panels Do?

Solar panels generate electricity by harnessing the sun’s solar energy and converting it into usable electricity for your home. There are many pros and cons to solar panels for your home, including lower energy bills and a higher upfront cost, respectively—but overall, solar energy can be an excellent investment for many homeowners. 

When you opt for solar panels, you’ll find that they:

  • Function as an alternate form of energy that does not rely on the electrical grid

  • Reduce, or even eliminate, electricity bills

  • Lower your carbon footprint

  • Can generate rebates through supplying electricity to your local utility company

  • Prevent blackouts during adverse weather

How Do Solar Panels Work?

Understanding how solar panels work can help you decide on the right type of solar panel system that best suits your needs. Here’s the 411 on how solar panels provide electricity to your home.

Solar Panels Harness Solar Energy

First and foremost, the sun’s rays hit your solar panels. Solar panels use photovoltaic (PV) cells made of silicon, boron, and phosphorus to convert the sun’s radiation into electricity. The silicon cells are semiconductors comprised of two layers—one that’s positively charged and one that’s negatively charged. 

The boron and phosphorus work to create an electrical current. When activated by solar rays, the photons in the light cause the electrons in the PV cells to become energized, where they then loosen and break free. 

The Inverter Converts Electricity 

After the energy process, the electrical current travels to an inverter. Again, though your solar panels create power, that power comes in the form of direct current (DC) energy. This power must get converted from DC to alternating current (AC) electricity. 

DC energy runs in one direction—like vacuuming only from left to right—while AC energy runs back and forth, like vacuuming left to right and then right to left. 

An inverter works by using electromagnetic switches to frequently flicker on and then off again, creating an alternating current similar to AC energy. Some inverters also contain transformers and filters to synchronize the electrical waves so they run more smoothly for appliances that depend on a stable alternating current. 

For example, your electronic devices and medical equipment might depend on smooth electrical sine waves to run and might get damaged by an unstable current.

Your Breaker Box Distributes the Electricity

To get distributed throughout a household, the now-converted energy runs from the inverter to the main electrical panel of your home, where it then gets sent to your appliances. You won’t notice any difference between the energy used from the electrical grid and the energy that enters the home through your solar energy system. 

However, if your solar panel system size is over 4.25 kW, you might need to upgrade the panel box—especially if it’s 100 amps. A 200-amp panel box typically has a max capacity of 12 kW, which is plenty for the average residential solar panel system.  

Store or Supply Excess Electricity

Now that you understand how solar panels work, you’ll want to consider your options for dealing with excess energy. There are two options for handling excess energy that your solar panels produce: storing it through a solar battery system and sending it to the power grid. Here’s how each option works.

Storing Excess Electricity

If you live off-grid or want complete energy independence, you’ll need to invest in a solar battery backup system for your home. Most solar batteries use lithium ions to react with free electrons and store the energy until it’s ready for you to use it. 

When you are ready to tap into your battery backup, positive lithium ions move from one end of the battery to the other end, creating a usable electrical current.

Supplying Excess Electricity

If you’re planning on using the grid in conjunction with your solar energy system, you’ll need a net meter to get reimbursed for excess energy you send to your local utility company’s grid. Called net metering, homeowners who choose a hybrid of both solar and traditional energy will only want to get billed for the net energy consumed by their homes. 

To get reimbursed, utilize net metering to export solar power generation to the grid to lower how much energy you used from the utility company. You will likely receive a credit on your utility bill for supplying the grid with extra energy.

What Are the Parts of a Solar Panel System?

If harnessing the power of the sun to bake cookies or turn on a lamp sounds enticing to you, you’ll want to understand the system as a whole before proceeding with installation. Take a look at how a solar power generation system works with all the components below. 

Solar power system components include: 

  • Solar panels

  • Rack and mounting 

  • Inverter

  • Storage battery (optional)

Solar Panels

The most obvious part of the solar panel system is the solar panel. There are three types of solar panels, including monocrystalline solar panels, polycrystalline panels, and thin-film, with the first two types being the most commonly used in residential homes. The panels capture and conduct the sun’s rays into DC power. 

Rack and Mounting 

As easy as it would be to install solar panels by simply laying them on top of your roof, you’ll need a rack and mounting system to secure the panels and give them the best chance of capturing as much energy as possible. For homes in climates that have sparse sunlight, using a solar tracker helps ensure your panels capture as much sunlight as possible.

Inverter

So, your solar panels produced DC electricity, which means it’s ready to use, right? Unfortunately, most appliances in your home don’t work with this form of power—they use AC electricity. This is where the inverter comes into place. The inverter is responsible for converting that energy into usable electricity within your house.

Solar Battery Storage

This optional component of a solar panel system stores excess energy for use when the sun goes down or when your home uses the readily available energy produced by the solar panels. Fully off-grid solar panel systems will need battery storage, but if you plan on tapping into the grid in combination with your solar panels, you might not need solar battery storage.

Now that you know all about how solar panels work and what they do, talk to a solar panel installation company about getting a quote for your home. 

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