Become a solar panel wiz before you buy
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.
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.
How do solar panels work? Here’s everything you need to know about what solar panels do and how they work.
Before you call a local solar installation company and make the leap to solar panels, 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 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.
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 of solar energy, including lower energy bills and a higher upfront cost to install solar panels—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 local utility companies
Prevent blackouts during adverse weather
Understanding how solar panels work can help you choose the right type of solar panel system for your needs. Below, we’ll illuminate how solar panels provide electricity to homes.
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. 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, photons in the light cause electrons in the PV cells to become energized, and they loosen and break free.
After the energy process, the electrical current travels to an inverter. Though solar panels create power, that power comes in the form of direct current (DC) energy. Power must get converted from DC to alternating current (AC) electricity in order for you to use it in your home.
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, electronic devices and medical equipment might depend on smooth electrical sine waves to run and might get damaged by an unstable current.
Converted energy runs from the inverter to the main electrical panel of your home, which sends it to appliances. You won’t notice any difference between the energy from the electrical grid and the energy from 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.
Now that you understand how solar panels work, consider your options for excess energy. There are two options for handling excess energy that solar panels produce: storing it in a solar battery system and sending it to the power grid. Here’s how each option works.
If you live off-grid or want complete energy independence, you’ll want to learn how to increase solar power efficiency and invest in a solar battery backup system. Most solar batteries use lithium ions to react with free electrons and store the energy until you want 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.
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. This is called net metering and ensures that homeowners who choose a hybrid of solar and traditional energy will only pay for the net energy consumed by their homes.
To get reimbursed, use net metering to export excess solar power to the grid. This will lower the amount of energy you use from the utility company, and you will likely receive a credit on your utility bill for supplying the grid with extra energy.
Solar panels are a combination of high-tech and traditional building materials. Depending on the type of panels you have, here’s what solar panels are made of:
This is the most common material in solar cells. There are three main types of silicon.
Monocrystalline silicon: Made from a single crystal structure, monocrystalline silicon is highly efficient and takes up less space.
Polycrystalline silicon: Formed by multiple crystal structures, this form of silicon is generally less expensive and slightly less efficient.
Amorphous silicon: This non-crystalline form of silicon is part of thin-film solar panels. It’s typically less efficient than monocrystalline and polycrystalline silicon and is flexible.
Metals like silver and aluminum make up the conductors, which are the electrical contacts that allow the electricity to flow.
Transparent glass on the front of solar panels protects the solar cells and allows sunlight to pass through.
Encapsulant materials, usually ethylene-vinyl acetate (EVA), encase the solar cells to protect them from moisture and mechanical damage, increasing how long solar panels last.
This layer on the back of solar panels is often made of durable plastic or polymer. It protects the solar cells and provides electrical insulation.
Solar panel frames, typically made of aluminum, hold the solar installation together and provide structural support for mounting.
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)
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.
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.
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.
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 there are ways to use solar panels directly without batteries. For example, if you plan on tapping into the grid in combination with your solar panels, you might not need solar battery storage.
The rule of thumb is to install solar panels so they face in the direction of the equator. This way, they receive more sunlight to power your home with solar energy. A solar panel installation pro can consider obstacles and help plan your system.
The average solar panel installation costs about $27,000, although it can cost much less or much more depending on the size of the system, type of solar panels, wattage, battery storage, and more.
When calculating solar panel costs, be sure to calculate tax credits and incentives that can bring down the overall cost. You may also qualify for financing options, solar panel leasing, or be able to sell energy back to the grid.
Along with photovoltaic (PV) solar panels, other types of solar technology can help you make your home more eco-friendly and less reliant on public power utilities.
Solar hot water systems use sunlight to heat water. Most solar water heating systems consist of solar collectors mounted on the roof that transfer heat to a storage tank. Depending on the home’s efficiency needs, you can choose between flat-plate or evacuated tube collectors.
Flat-plate collectors are the most common and cost-effective. They are made of a flat, insulated box with a glass or plastic cover. Evacuated tube collectors work best in colder climates and consist of glass tubes that better maintain heat.
Solar thermal energy systems capture and use solar energy for heating. These can include space heating inside homes rather than conventional heating systems, and swimming pool heating systems that efficiently heat pool water and extend the swimming season.
Like solar hot water systems, solar thermal energy systems usually include collectors, storage tanks, pumps, and controls. The size of the system depends on your needs. Benefits include energy efficiency, cost savings, a lower environmental impact, and less maintenance than traditional heating systems.
Solar air heaters use the sun to heat air, which they then circulate through the home to heat the space. These often include solar collectors and a fan system.
Solar generators combine solar panels with battery storage to provide electricity. While small units are popular on campers and recreational vehicles, larger units can provide power backup for homes.
