How Do Solar Panels Generate Power?

How Do Solar Panels Generate Power?

renogys blog Nov 24th 2021

Every day, more and more homeowners are investing in solar energy and reaping the savings benefits. Whether you’re looking for a solar panel installation for your home or considering purchasing a portable solar generator to take with you on the road, there are solar power panels available to meet your needs.

However, even many homeowners with solar panel systems don’t know exactly how their panels provide renewable energy to their homes. Fortunately, solar electric systems are not actually all that complex, especially once you understand the underlying science.

In this article, we’ll take a deeper look at how your solar panels work, from their various parts to how your residential solar system can save you money on your electric bills.

What Parts Go into Solar Power Panels?

Despite appearances, your solar power panels are actually fairly straightforward pieces of equipment with only a few important parts. These surprisingly simple solar modules work in an array to help you produce clean, renewable energy.

Silicon Wafers

Inside your solar panels are a series of silicon wafers, and these are the most important part of your solar panels. These wafers consist of two layers: one positively charged and the other negatively charged. The P-type layer is fabricated with silicon ions missing an electron, while the negative N-type is made with an additional electron.

When put together, these wafers create what is called a photovoltaic (or PV) cell. Home solar panels rely on a PV system to generate electricity by laying rows and rows of cells together on a single panel, then connecting them to each other and allowing current to pass into your electrical system.

Coated Glass

The top layer of your solar panels is tempered (or toughened) glass. This top layer helps protect your PV cells against the elements while adding extra strength to the structure of the panel. The glass also comes with a coating that limits UV damage to the cells while also insulating the PV cells from damage related to excess vibrations.

Contact Grid

One of the most visible parts of a solar panel is the small lines moving across the surface. This is the contact grid, which is attached to the glass. The grid collects electricity from the PV cells and transfers it to the main power line.

Backing Panel

In addition to adding another layer of protection and making the structure of your solar panel as strong as possible, the opaque backing panel in your solar modules also helps insulate your PV system from the outside world. Without this panel, it would be possible for the electricity you generate to “leak” from the panel, lowering your efficiency and potentially increasing the risk for an electrical fire.

How Do Solar Power Panels Generate Electricity?

Knowing the different components of your solar panels is undoubtedly important. But parts and equipment are only a tiny portion of how your solar energy system actually produces electricity. Whether you install your own home solar panel kits or you rely on a professional solar installer, your solar panel system relies on the same sunlight to generate renewable energy.

1. Panel Is Activated by Sunlight

When you install a solar panel system, you’ll usually need a number of panels next to each other, creating a solar array either on your roof or in a nearby area that receives direct sunlight. Making sure that your panels are exposed to as much sun as possible is key to getting your solar power system to work.

Although it looks invisible, sunlight actually contains a number of particles called photons (derived from the word “light”). When these photons hit other particles, the energy they contain is transferred into other forms, most often heat. It’s this effect that makes sunlight so attractive for cats looking to take a nap.

When photons hit particles in your PV cells, it dislodges the extra proton in the negatively charged layer of the silicon wafer. That electron is then attracted by the positive charge on the other layer of the wafer.

2. Electric Current Is Produced by Cells

As the sunlight excites the extra electrons in your PV cells, they begin to alternate between the two layers of the silicon wafer. That alternating transfer between the layers is what causes an electric current to be produced in your solar panel.

Silicon is an extremely stable element, and because of that, the loose electrons continue to swap back and forth as long as the sunlight continues the reaction. Since that imbalance between the positive and negative layers never fully equalizes, your solar panel should continue to generate electricity all day long.

3. Converting Electrical Current

As your solar reaction continues, your electric panel produces what is known as direct current, or DC. However, virtually all home electrical systems use a form of electricity known as alternating current (or AC). While this sounds like a problem, in reality, the power delivered to your home from the electrical grid is also DC since it’s more efficient over long distances.

Still, you need to transform the DC produced by your solar power panels, which means transforming the energy from DC to AC. This is done with a device known as a string inverter—often just called an inverter. This device connects your solar panels into one line, which then converts the DC electricity into AC. You can use this electricity to run your home appliances, lighting, and other electrical needs.

The Impact of Solar Power Panels on Your Electricity Usage

While many homeowners would like to rely on complete solar power to run their homes, most states and cities require homes also to be connected to the power grid, primarily as a matter of safety. Solar panels only work when there is sunshine, and because that is out of your control, you need to tap into the electrical grid to keep your home running when your solar energy system can’t meet your needs.

Your solar panels can only produce electricity from the sunshine. When it’s cloudy or dark outside, you consume energy without being able to replace it. On the flip side, when your system is producing the most power—the middle of the day—you’re much more likely to not even be home.

But solar power can still help you cut your energy costs, especially when you add a few extra steps to your solar power system. Here are two solutions that you can use: net metering and battery backup.

Net Metering

With net metering, you work with your energy provider to measure the amount of power you consume from the electric grid when you’re out of solar power while also tracking how much solar energy you feedback into the grid when you produce more than you use.

At the end of each billing period, your power company will compare the amount of energy you used against what you contributed and then give you a bill for the difference, which can end up saving you a lot of money.

Be aware, though, that most companies bill different rates at different times based on demand. You may pay more for the energy you consume during high-demand times than they’ll pay you for energy produced during low-demand hours.

Battery Backup

Many homeowners also invest in storage batteries to hold the excess solar energy they produce. While your home has first priority for the electricity you generate, the excess flows into your batteries, where it’s stored until you need it.

You should be aware of two drawbacks to batteries, however. First, while storing energy in your home can save you money, batteries are less efficient than sending power back into the grid, and that lost power can add up over time. The second point is that even with batteries, you will still likely need to draw from the electrical grid to meet your energy needs. 

Difference Between PV Solar Power Panels and Solar Thermal Panels

For the most part, homeowners are going to be dealing with PV solar power panels. However, you should be aware that another type of panel is concentrated solar-thermal panels (CSPs). While CSPs still rely on sunlight to produce energy, they don’t use PV cells. Instead, they concentrate sunlight using an array of mirrors, sending that concentrated sunlight to specialized receptors that store that energy as heat.

In order for CSPs to work efficiently, however, they usually require a much larger scale than PV systems, which is why you’re only likely to see CSP systems in power plants or other large-scale settings.

Consider Installing Solar Power Panels on Your Home

Solar power isn’t just a way for you to save money on your electric bill. It’s also a way for you to help commit to renewable energy, helping create a better future for tomorrow.

Now that you know how solar panels generate electricity, you should feel confident about investing in solar power for your home. Whether you employ professional installers or prefer a DIY solar panel kit, now is the time to start your solar journey.