As solar becomes more mainstream, many people are beginning to question how a solar panel creates electricity. The process is quite simple, but the physics behind it are more complicated. So, how does sunlight become usable electricity for your home or business?
Solar energy is made possible by certain metalloid chemical elements. These are elements that when exposed to sunlight, produce an electrical current. For most solar panels in the U.S., this is the crystalline element silicon (Si) and the reaction that produces electricity is called the photovoltaic effect (or PV for short).
Once the electric current is generated, it is captured and converted into a usable form that is then distributed throughout your home. To better see how this process works, check out this brief video from the U.S. Department of Energy:
How Are Solar Panels Made?
Solar cells are the building blocks of solar panels. A solar cell consists of a thin, square silicon wafer sandwiched between multiple metal contacts that harness electricity from the PV effect. There are two types of silicon used in solar cell construction: monocrystalline and polycrystalline. Monocrystalline panels are more efficient and work well in low light conditions, which means they are more flexible and make good use of roof space. Polycrystalline cells are slightly less efficient and don’t work as well in low light conditions but are more affordable.
Solar panels are made up of multiple solar cells. These are easily identified by their square shapes with lines (metal contacts) running through them. The cells are grouped together and laid on top of a solid back sheet and insulation, which prevents the panel from getting too hot and eliminates moisture buildup. The cells are also covered with an anti-reflective coating so they can better absorb sunlight. The cells are then sandwiched between an encapsulant and placed into a metal frame covered with a tempered glass face for durability.
Solar panels can contain between 36 and 144 solar cells. However, the most common residential solar panels contain 60 cells while those used for commercial applications contain 72.
A typical residential solar panel produces approximately 250 watts of electricity. That means if your home requires a 5-kilowatt system (5,000 watts), you’ll need 20 solar panels. Likewise, a 7.5-kilowatt system requires 30 panels and so on. There are higher efficiency panels available that can produce up to 400 watts of power and the kind used for your home depends on the type your installer uses most often. Of course, you can always request a different efficiency level, but this will probably add to the cost of your system.
That being said, the actual output of your system will be determined by many factors such as orientation, placement, and shading among other things. Simply having a solar panel that’s capable of producing a certain amount of electricity doesn’t mean it will be able produce that amount of power 100% of the time.
What Are Inverters?
There are several components to a home solar panel system. One of these is what’s called an inverter and it’s probably a term you’ve heard frequently.
As mentioned earlier, the electricity produced from your home’s solar panels needs to be converted into a usable form. That’s because solar panels produce only direct current (DC) electricity. Your home and the entire electric grid uses alternating current (AC). An inverter takes the DC current from your solar panels and turns it into AC before it’s distributed to your home or business.
As with solar panels, they come in different sizes and some are more efficient than others. However, each solar system must have an inverter to function properly. Inverters are also an essential component of backup battery systems, which rely on them for the same reasons.
How Does My Solar Panel System Operate With The Electric Grid?
Many first-time solar owners believe that once their system is installed, they are free of the electric grid. The truth is that most home and business solar panel systems are grid tied.
There are two reasons for this. First, you need grid electricity for the times when the sun doesn’t shine, like during the evening hours. Also, most states have what’s called a “net metering” law that allows you to sell any extra power your solar system produces back to your electric utility. To do this, you need to be connected to the grid and have a special bi-directional meter that tracks what you use versus what you sell.
For most homeowners, they sell back more than they use, which the utility then pays you for in the form of bill credits. Over the course of a year, these credits wipe out any electrical charges from the grid leaving you with only the standard connection fee, which is usually around $15-$25 a month.
For more information on how net metering works, check out this video from Shine Solar:
So now that you understand how solar works, what are you waiting for? Call Shine today at 844-80-SHINE or visit our website at www.shinesolar.com and let us show you how easy it is to virtually eliminate your electric bill and become energy independent.