How Do Solar Panels Work?

graphic showing how a solar power works

We all know that solar panels are able to transform light from the sun into electricity. These days, it’s not uncommon to see such semiconductor panels installed on rooftops or even on top of roadside signs. But how do solar panels work? How do they exactly convert light into electric current and renewable energy?

Even in the pulp era of science fiction back in the 1920s and 1930s, solar technology was no longer just a what-if but a reality waiting to be developed further. And while it was in 1839 that French physicist Alexandre Edmond Becquerel discovered the photovoltaic effect, it wasn’t until 1883 that Charles Fritts made the first solar panel. So when he was able to convert 1% of the sun’s light into electricity, it was a big deal at that time – spurring the solar industry to develop the technology to what we’re enjoying today.

What is Solar Power?

Solar power comes from the light emitted by the sun. It is a clean source of renewable energy, which means there are no greenhouse gas emissions released into the atmosphere to harness it. Solar power can be converted into two types of energy we can use – heat and electricity.

Fortunately, this is also the most abundant energy source we can harness – even on cloudy days. Did you know that around 173,000 terawatts of solar energy hit our planet at any given time? This is roughly more than 10,000 times the total energy requirement of the entire world.

Since this electricity system is a renewable and inexhaustible form of energy, the U.S. government even encourages its use by giving tax credits and other incentives to those who would switch to solar for their home or business’s electricity needs.

It’s no surprise that solar power is one of the fastest-growing sources of clean energy. It’s free, reliable, and eco-friendly. All you have to invest in is the equipment that will capture the light and transform it into usable solar electricity.

Types of Solar Panels

  • Monocrystalline Solar Panels. Due to their manufacturing process, monocrystalline solar panels are more expensive than the other types. However, it’s still the most effective. Many homeowners prefer this type since the primarily dark black solar cells surrounded by white areas can blend in with most house styles and designs.
  • Polycrystalline Solar Panels. These panels look less consistent since they contain several crystals instead of a single one. And since this process reduces the cost of production, the price of polycrystalline panels is much lower than that of a monocrystalline. Although the difference is minimal, they have less purity than mono panels – reducing the efficiency when converting the sun’s light to energy.
  • Passive Emitter and Rear Cell (PERC) Solar Panels. A PERC solar panel is just a subset of the first two types but the extra steps involved in its manufacturing process enhance the original design. The resulting reflective quality helps in giving it the best energy efficiency rating and improved sunlight conversion.
  • Thin-Film Solar Panels. Thin-film solar panels are commonly referred to as flexible solar panels because they can be created using a variety of materials, unlike the other three types, which use silicon. This type makes use of photovoltaic materials, including amorphous silicon (a-Si), copper indium gallium selenide (CIGS), and cadmium telluride (CdTe). And out of all the types, thin-film solar panels look more elegant and can match practically any roof.

If you want to learn more about each type of solar panel, as well as the pros and cons of each, you can check out this detailed guide.

How Do Solar Panels Work?

Understanding the inner workings of how solar panels convert light to electricity is not that complicated if you keep in mind this one particular phenomenon – photovoltaic effect. This is the ability of PV cells, or photovoltaic cells, to produce electrons when it’s bathed in light. That’s why solar panels are also known as solar PV panels or solar photovoltaic panels.

So how is solar used to power your home? Here are the steps that happen when turning light into electricity using PV panels:

1. Solar Panel Receives and Converts Light

As sunlight photons hit the panels, the PV system creates an electrical field, which is due to the solar photovoltaic effect. The electrons produced are set into motion, flowing out from solar cells to the junction between them, creating electricity. However, this is still in the form of direct current, or DC electricity, which is not yet usable. With the help of a conductive wire, the DC electricity is brought to the microinverter.

2. Inverter Transforms Electricity to Usable Power

As soon as the inverter receives the DC electricity, it runs the DC through a transformer, producing an alternating current, or AC power output. For this process to happen, the solar inverter passes the DC through two or more transistors that rapidly turn on and off and feed two different sides of the transformer.

3. Usable Power is Sent to Your Home

Now that the sun’s energy has been converted to AC electricity, another wire transports it from the inverter to your property’s electric panel. Also known as a breaker box, this panel distributes the electricity throughout the power outlets in your property as required.

4. Excess Power is Sent to the Grid and Credited to You

You’re not wasting anything when you have a solar panel installation. Any excess electricity generated flows through your utility company’s net metering system and into the electrical grid. As the electricity flows through the meter, it causes it to run backward. And as a result, your property gets credited for excess energy generated by your solar energy system.

What is the Cost of Solar?

When you include the materials and professional installation to set up solar panels for your home, it would usually be around $20,000. Depending on other factors, though, most homeowners would shell out between $15,000 to $26,000.

It is quite a hefty price tag if you view it as an expense. However, most Americans consider solar panel installations as an investment due to the benefits it brings, such as reduced electricity bills and increased home value. This is including the incentives and tax credits the government offers to qualifiers.

While buying solar panels with cash is undoubtedly cheaper, there are finance options available that can help ease things up if you don’t have $20,000 to spare. Some other ways that can help you purchase a solar array system include the following:

  • Personal loans
  • Government-sponsored loans
  • In-house financing

Keep in mind, though, that interest rates and financing terms are going to add up to the total cost. You can check our pricing guide for more specific and in-depth information about the cost of solar panels.

Pros and Cons of Solar Panels

Are you still on the fence about switching to either monocrystalline or polycrystalline solar panels? Just think of how you’re saving the planet if you don’t rely on fossil fuels and power plants to provide electricity for your home. Here is a quick rundown of some of their pros and cons to help you decide more confidently and smartly.

Pros

  • Lower utility bills
  • Unaffected by rolling blackouts
  • Friendly to the environment
  • Impervious to electricity price hikes
  • Potential for another income stream

Cons

  • Expensive upfront costs for the materials
  • Cost of installation
  • Limited local service providers

These are just a few of the things you can expect with solar technology. If you want more information about its advantages and disadvantages, we recommend that you check our detailed article on the pros and cons of solar shingles.

Is Your Home Good for Solar?

When setting up your home to go full solar, you need to consider other factors apart from the cost. It’s pretty much like planting a tree, where you need to see to it that your soil can support its growth. In this case, you need to ensure your home’s infrastructure can accommodate the solar panel system and maximize its capability throughout its lifetime.

Here are some of the questions you should answer before going forward:

  • Can your roof structure support solar panel installation?
  • Do you need to upgrade or strengthen your roof?
  • How much sunlight does your roof receive?
  • Are there any hazards that should be removed, like tree branches?
  • What is the local climate and weather system?
  • How much is your monthly electricity bill?

We’ve written an extensive article to help you give attention to the most significant factors to consider before making the big switch. You can read it to make switching to solar energy easier for you.

FAQ About How Solar Panels Work

How do solar panels work when power goes out?

Silicon solar cells work even when the power goes out. But for the panels to work even during a blackout, you need to have solar battery storage. It works like a generator or a spare battery that provides energy to your solar power system at times when the panels can’t generate power, such as during power blackouts. A solar storage battery gets its charge from the excess electricity that your solar panels generate.

Can a house run with solar power alone?

Yes, current solar energy solutions are now capable of providing all the energy needs of a house. The combination of solar modules and solar batteries makes this possible, powering an entire home with solar energy exclusively.

Do solar panels work even at night?

Yes, they do, but at a very minimal output. Moonlight actually reflects the light from the sun, so it still has the same properties that can be converted into electricity, albeit trivial.

Use Solar Technology to Harness the Sun’s Free and Limitless Energy

Converting the sun’s energy into electricity that our home can use is not magical but a work of science. As such, with proper setup and conditions, it can be replicated and installed in every home. Take advantage of this ever-growing movement and make the shift while incentives still abound.

Connect with local solar providers to help you save on electricity bills while you’re saving the world as well.

Main Illustration Credit: Juan Rodgriguez for RoofGnome

Melanie Joseph

After discovering her passion for writing through her beauty blog, Melanie left her engineering job in California, became a writer, and never once looked back. When she isn't writing, she loves dipping in the pool, tending to the garden, or doing simple home improvement projects.