The sun is the most easily accessed form of energy and power. The way solar panels work is that they capture, or harness, the sun’s energy and then take that energy and turn it into an electrical current (or electricity). This current is then used to provide the power and electricity to your home, business, etc.
The Science of Solar Energy In Brief
Solar panels are made up of specialized solar cells that absorb the sunlight. As the sunlight is absorbed, a process called the “photovoltaic effect” converts that sunlight into an electrical current. This current is captured by wires and plates inside the solar panels. The solar panels then convert the electrical current into a usable energy current which is sent throughout your home to power the lights and various appliances.
So What Exactly Is Solar Energy
Solar energy is one of the most accessible and affordable forms of renewable energy available to the public. Most of us know that solar panels exist and can be used to help power our homes and businesses. But not as many know what exactly solar energy is, and why it’s such a great form of usable energy.
Nuclear Fusion Creates Solar Energy
The sun is constantly creating energy as a result of ongoing nuclear fusion reactions deep within its core. Everything is made up of moving molecules. In the case of the nuclear fusion occurring inside the sun, the protons are the key players. Protons are basically the same as hydrogen atoms.
Due to the extreme temperatures and pressure inside the sun’s core, the protons become very activate and crash into each other and then fuse, creating helium, as well as more protons. Because this process of nuclear fusion literally never stops, the energy produced is limitless.
Imagine an energy source that produces more than 500 million tons of hydrogen atoms each second! That’s solar energy, and that’s why solar panels are so viable and sustainable.
Electromagnetic Radiation (EMR)
The sun is incredibly powerful. Not only does it have constant nuclear fusion occurring in its core, it’s also hotter than anything the human mind can comprehend. It reads temperatures around seven million degrees Fahrenheit.
Electromagnetic radiation is the form of energy released by the sun due to its extreme temperatures. There isn’t just one form of electromagnetic radiation (EMR), and interestingly, the sun produces every type of EMR. You can think of the EMR released by the sun as particles of energy. These come to earth in the form of photons.
What Powers Solar Panels
The basis of solar energy is when photons (or particles of sunlight) effectively crash into electrons, which sets them in motion and frees them from the atoms they were attached to. This creates electricity.
Solar Cells Make Up Solar Panels
To put it very simply, solar panels are made up of millions of cells called solar cells. These solar cells are specifically designed to capture the energy flow (electricity) from the sun, and turn it into an electrical current that’s usable.
The Photovoltaic Effect
When the solar cells in the solar panels capture and convert the sun’s energy, they’re undergoing a process called “the photovoltaic effect”. This effect, or reaction, is very important because it’s the physical and chemical process behind all modern solar technology.
The History of the Photovoltaic Effect
Like we mentioned, the photovoltaic effect is the single most important process in the generation of electricity via solar panels.
A little background on its discovery: Edmond Becquerel was the first scientist to discover the photovoltaic effect. In 1839, Becquerel discovered that certain materials (or semiconductors), when exposed to sunlight, have the unique ability to take the sun’s energy and turn it into an electrical current.
How the Photovoltaic Effect Works
We’ll briefly describe the three main steps in the photovoltaic effect, and how those steps relate to solar panels.
Step 1: The Electrons Get Moving
Solar panels are made up of solar cells. The solar cells are filled with electrons which are in a constant state of motion. When the sunlight hits the solar cells, the electrons become energized. It’s this energy that sends the electrons into rapid motion.
Step 2: The Electrons Travel Between the Cells
All cells, whether they’re solar cells, cells in the human body, or the cells in plants, are all connected by junctions. Now that the electrons in the solar cells are moving rapidly, they need somewhere to go, so they begin flowing between the solar cell layers via these junctions. This flow is what creates an electrical current.
Step 3: Electricity Is Generated
In order for the solar cells within the solar panels to actually do anything, the panels themselves have to have some kind of structure. Metal plates and wires in the solar panels give them that structure. They also create a kind of roadway system for the electrons to move along. The movement of the electrons is captured by the wires and plates, generating electricity.
Solar Cells are the Key Players In Solar Panels
Solar cells are the key players in the generation of electricity because they’re where it all starts. Solar panels are made up of many individual solar cells, in addition to the metal plates, and wires.
Solar Cells are Semiconductors
Solar cells are basically a bunch of semiconductors. This means that they’re made up of materials that are extremely good at trapping and absorbing sunlight and converting it into electricity.
Silicon Is the Most Common Semiconductor Used In Solar Panels
Silicon is the most commonly used nonmetal semiconductor in solar cells. About 95% of the solar cells manufactured today are made up of silicon.
Silicon is also an element that you can find it on the periodic table as atomic #14. In addition to being the most commonly used semiconductor in solar cells, silicon is also used in the majority of computers in the world.
The Role of Silicon In Photovoltaic Cells
Photovoltaic cells are made up of two layers of specially treated (“doped”) silicon. This treated silicon at the junction between the layers of the photovoltaic cells is what creates the electric field.
As the electrons move around in the solar cells, the electric field forces the loose ones out of the silicon junction. It’s this action that creates the actual electrical current produced by/in solar panels.
Positive and Negative Sides of Photovoltaic Cells
Each photovoltaic cell has a positive side and a negative side. The doping agents used to create these opposite poles are phosphorus and boron.
Phosphorus and Boron
Phosphorus is the doping agent that gives the photovoltaic cell a positive side, and boron is the agent that gives the photovoltaic cell its negative side.
How Electrons are Turned Into Electricity
Once the electric field is created at the junctions between each photovoltaic cell, something has to collect the expelled electrons, and then give them a way to travel. Each solar cell is given structure by metal plates. These plates collect the electrons and then send them along the wires that connect each cell.
Electrons are Now Electricity
Once the electrons have been collected by the metal plates and then sent along the connecting wires, those electrons have officially been turned into electricity.
Solar Inverter
The solar inverter is another important piece of the puzzle of photovoltaic cells and their ability to generate electricity. The solar inverter is where the electrons (in the form of electricity) are sent. Another way to think of the solar inverter is that it’s a housing and transfer station. Once the electrons have been sent to the inverter, the solar inverter then sends that electricity throughout your house.
Three Alternatives to Silicon Solar Cells
Universally, silicon is the most commonly used nonmetal semiconductor in the manufacturing of solar panels. However, in some of the new and emerging solar products, silicon alternatives are used.
All of these silicon alternatives are made of very thin materials that are also very flexible. While all of these materials are of different composition, they’re referred to as thin-film solar cells.
Thin-Film Solar Cells
Thin-film solar cells are the first type of silicon solar cell alternatives. Thin-film solar cells are named as such because they’re constructed out of flexible and lightweight material.
All solar cells have light-absorbing layers. Thin-film solar cells, however, have light-absorbing layers that are 350 times smaller than those in silicon cells.
4 Main Chemical Types of Thin-Film Solar Cells
Thin-film solar cells come in four main chemical types. There’s Amorphous Silicon (a-Si), Cadmium Telluride (CdTe), Gallium Arsenide (GaAs), and Copper Indium Gallium Selenide (CIGS). Although these solar cells’ chemical types are different, they’re all still lightweight and flexible.
Organic Solar Cells
Organic solar cells, or organic photovoltaics (OPV’s), are the second silicon solar cell alternative. They are also thin-film solar cells, but they’re different than the standard thin-film solar cells because their manufacturing relies on using carbon-based materials as their semiconductor.
Organic solar cells are also called “polymer solar cells” or “plastic solar cells”. The production of this type of solar cells involves organic compounds being dissolved in ink and then the resulting solar cells being printed onto thin pieces of plastic.
Perovskite Solar Cells
The third class of thin-film solar cells are built out of perovskites, hence their name, “perovskite solar cells.” Perovskites are a class of manmade materials that are extremely efficient at turning photons (of light) into usable forms of electricity.
The unique crystallographic structure of perovskites is what gives perovskite solar cells their incredible efficiency. Another interesting feature of perovskite solar cells is that they’re built using the identical process and technique as is used to print newspapers. This is called “solution processing”.
Other Parts Essential To Solar Panels
Solar cells aren’t the only parts necessary for solar panels to function. Solar panels are made up of a few other important parts that are essential to their functioning.
Glass Casing
All solar panels need some kind of protection. The silicon PV (photovoltaic) cells need something that offers protection and durability. Glass provides the ideal protective exterior material.
Insulation
Glass alone can’t provide all the protection the solar cells need. Directly underneath the outer glass casing of the solar panel, is a layer of insulation. There’s also a back sheet that helps to protect against humidity and heat dissipation that occurs inside the solar panel.
The insulation layer is arguably one of the most important protective layers for the solar panel and its cells. This is because too high of temperatures lead to a decrease in the solar cells’ and panels’ efficiency. This decrease in efficiency causes an overall decrease in the solar panels’ performance.
Anti-Reflective Coating
The anti-reflective coating plays a big role in solar panel performance and effectiveness. Although solar panels need to be protected from extremes of heat and humidity, they need to absorb as much sunlight as possible.
The anti-reflective coating ensures that the maximum amount of sunlight is absorbed by the solar panels and its cells. Essentially, this coating is increasing the sunlight exposure the panels have.
Two Cell Formations of Silicon Solar Cells
In the manufacturing of silicon solar cells, there are typically two cell formations, or structures, that are produced. These are monocrystalline cell formations and polycrystalline cell formations.
Monocrystalline
A single silicon crystal makes up the monocrystalline cells.
Polycrystalline
Multiple silicon fragments make up the polycrystalline cells.
Monocrystalline vs. Polycrystalline
On the surface, the difference between these types of silicon solar cells seems insignificant. However, the monocrystalline format is actually more efficient and makes for a solar technology that’s higher efficiency than that produced by the polycrystalline format.
The reason for this difference is that in the monocrystalline format, there is a lot of room for the electrons to bounce around and move and travel across the junctions between the solar cells.
Monocrystalline solar technology is more expensive than polycrystalline, but since it’s about 20% more efficient, it’s understandable that you would pay more.
How Solar Panels Generate Electricity for Your Home
The first step in the working of any solar panel is to generate an electric current. However, that’s not the end of the process. The process of creating, or generating, usable electricity for your home consists of multiple steps. They are as follows.
Step 1: Photovoltaic Effect Turn Sun’s Energy Into DC Electricity
The photovoltaic effect starts the whole process off by creating an electrical current. The solar cells that make up your solar panels absorb the energy given off by the sun, turn that energy into an electrical current, and then take that current and turn it into DC electricity.
Step 2: Solar Inverters Convert DC Electricity into AC Electricity
The photovoltaic effect is the process behind the creation of DC electricity. However, DC electricity isn’t a usable form of electricity. Somehow your solar panels need to generate AC electricity, which is the form of electricity that’s used by household appliances.
Your solar panels all have solar inverters built into them. The solar inverters take the DC electricity generated in your solar modules and then convert it to AC electricity. It’s common for your solar inverters to have built-in transformers that are responsible for regulating the voltage in DC and AC currents.
Step 3: Your Electronic Devices and Appliances are Powered By Electricity
Once the solar inverters have converted the DC energy to AC energy, they transfer the AC energy to the electric box in your house. The electricity then travels throughout your home on a network of wires, to all the outlets. Once the electricity reaches the outlets in your home, it’s available to use as soon as you plug in a device.
Step 4: The Electric Grid Gets Any Excess Electricity
It’s difficult to engineer solar panels that make only the exact amount of electricity needed by a home at any given time. There’s usually always an excess of electricity being produced by your solar panels.
Many solar systems are grid-tied, meaning that electricity flows not only to the power grid, but from it as well. Any excess energy your panels produce is a money maker for you. There’s a policy called net metering in which the power grid will give you credits whenever your solar panels send it electricity. This is a boon because it reduces your overall cost for electricity. You can learn more about the net metering policy here.
Are There Solar Technologies Other Than Photovoltaics?
The short answer is yes, there are other types of solar technologies out there. These solar technologies work differently than your traditional photovoltaic (PV) solar cells.
Photovoltaic solar (PV) cells are the most common way that solar energy is generated, and this is the solar technology that is most frequently used to power homes and businesses. However, sometimes there’s a need for other solar energy generation options.
Solar hot water and concentrated solar power are the two most common solar energy options.
Solar Hot Water Systems
Solar hot water systems are typically used for a very specific purpose. They generate heat that is used to give your home hot water.
Solar hot water systems differ from photovoltaic systems primarily in that instead of converting sunlight to electricity, they take the thermal energy given off by the sun and turn it into heat.
Components of Solar Hot Water Systems
Solar hot water systems have very different parts than photovoltaic solar systems. Like PV solar systems, solar hot water systems are installed on your roof. The components of a solar hot water system consist of: a storage tank, a heat exchanger, collectors, a backup heater, and a controller system.
How Solar Hot Water Systems Work
Like we said, solar hot water systems are used to capture the sun’s energy and convert it to heat. There’s no wild electron movement like what occurs in PV solar panels. This means that the heat generated by the solar hot water system is occurring passively.
The panels in a solar hot water system are called “collectors,” which are installed on your roof. The collectors are what passively collect the energy given off by the sun prior to converting that energy to heat.
Collectors are covered by a protective layer of glass. The sunlight hits the panels’ glass covering and passes through it, before coming to an absorber plate. The coating that covers the absorber plate is what then captures the solar energy prior to converting that energy to heat.
After the heat is generated, it’s then sent throughout small pipes running through the absorber plate via a “transfer fluid” (either potable water or antifreeze).
Concentrated Solar Power
Similar to solar hot water, concentrated solar power (CSP) transforms sunlight and turns it into heat. Concentrated solar power is also known as concentrating solar-thermal power, or concentrating solar power.
CSP isn’t used in homes, but is frequently used to help give power to the electric grid in utility-scale installations.
How Concentrated Solar Power Works
Like solar hot water systems, concentrated solar power systems work by transforming sunlight into heat. CSP technology is pretty interesting because it uses mirrors to produce electricity.
The mirrors do this by concentrating the thermal energy given off by the sun. The mirrors in a CSP installation reflect the sun’s light to a focal point. There is a receiver (or absorber) at the focal point that then collects the heat energy and stores it for later use.
Frequently Asked Questions About How Solar Panels Work
Solar technology is constantly changing and improving. This can make it seem hard and overwhelming to really understand how solar panels work.
Now that you’ve read about some of the science behind solar panels and how they generate electricity, we hope you’ve got a better understanding. Even so, here are some of the most common questions homeowners still have.
What are the Two Biggest Disadvantages to Solar Energy?
Solar energy comes with a big upfront price tag and it can also be pretty intermittent.
Big Installation Price Tag
Solar technology is generally more expensive than more traditional ways of generating energy. This is especially true of the installation costs. In the long run, though, investing in renewable energy really pays off.
To help reduce the initial cost of installation, there are various financial incentives like rebates and tax credits. This also helps to make solar technology more available to the general public.
Intermittency
The other biggest disadvantage to solar energy is that it can be intermittent. This applies to all forms of renewable energy. The resources used in renewable energy simply aren’t available at all times throughout the days and years.
An example of solar energy’s intermittency is that solar panels will produce less electricity on cloudy days and at night. Unpredictable or inclement weather can also cause the solar panels’ efficiency to drop.
One great solution to the intermittency problem is to consider a solar battery backup. This article can help you decide if you should look further into a solar energy storage option.
Can My Whole House Run on Solar Power?
Yes! Solar power can absolutely generate enough electricity for your home.
So What’s the Key?
You’ll want to be absolutely sure that your solar panels can function at their maximum efficiency. You can do this by selecting the correct type of solar panels, the installer, and the best angle of installation (of the panels) for your particular energy needs, as well as geographically on your roof.
Additionally, installing a storage option (battery) will give you more freedom if you don’t want to have to rely on the power grid at night or during bad weather, etc. This is important because even though a solar panel system will dramatically offset/reduce your energy use, there’s no system on the market that will maintain the same level of energy production at all times. This goes back to the problem of intermittency.
Will I Still Have Electric Bills If I Go Solar?
The short answer is yes, even if you have solar panels, you’ll still get a monthly electric bill.
Most solar energy systems are still grid-tied, meaning that your system can switch between generating electricity using just the solar panels, as well as getting electricity from the power grid.
There are some times when your solar panels won’t produce enough energy. This could be due to problems with intermittency, or simply that your home has increased its energy consumption. It’s during these times that you’ll owe money to your utility company because you’ll have had to get power from the grid.
The way to prevent relying on the power grid, and thus owing money to the electric company, is to rely solely on solar energy. You can easily do this by pairing your solar panels with a solar battery backup.
Will My Solar Panels Work At Night?
The solar cells in your solar panels require sunlight in order to generate electricity. This means the energy (and thus electricity) output will be higher during the day than it will be at night.
Although other light sources can help to generate a little bit of electricity at night, it won’t be much. That’s why pairing a solar battery storage system with your solar panels is the way to go. The battery storage system constantly collects and stores energy during the day which can then be used on cloudy days or at night.
So How Do The Solar Panels Work On My House?
Your installer figures out how many panels will be needed to sufficiently power your home. Then, to get the greatest benefit from the sun, the installer mounts and angles the panels on a south-facing roof.
Once mounted and installed, the solar panels absorb sunlight and convert the sunlight into usable electricity. If you’ve opted to also install a solar battery backup, the battery stores energy that can be turned into electricity for nighttime and cloudy day usage.
Get a Quote on Your Solar Panel Installation
At Convert Solar, we take pride in bringing clean, affordable energy to our local neighborhoods and businesses. Why? We firmly believe that solar energy is the way forward. It’s cleaner and leaves less of a carbon footprint; it can increase your home’s value; it helps you achieve energy independence; and it affords you protection from rapidly rising utility costs.
