How Solar Electric Systems Work
We can change sunlight directly to electricity using solar cells. Every day, light hits your roof’s solar panels with photons (particles of sunlight). The solar panel uses the energy of these photons to energize and release electrons creating direct current (“DC”) electricity. This DC electricity flows out of the solar panels and into an inverter and other electrical safety devices. The inverter converts that “DC” power (commonly used in batteries) into alternating current or “AC” power. AC power is the type of electricity the power company delivers to your home that your television, computer, and toasters use when plugged into the wall outlet.
Your power company installs a special meter which keeps track of the all the power your solar system produces. Any solar energy that you do not use simultaneous with production will go back into the electrical grid through the meter, creating a reserve. At night or on cloudy days, when you need more electricity than your solar system can produce, you will tap into your reserve first, before consuming electricity from the grid as normal. Your utility will bill you for the “net” consumption for any given billing period. At the end of the year, if any excess still remains in your reserve, the power company will “buy” this excess back.
You will also find PV used outdoors for security lighting, remote billboards, wells in remote cow fields, or any other application where the cost of delivering conventional electricity is prohibitive. Today you often see PV systems used to operate signs around schools or other road hazards.
Solar cells are small, semiconductors made from silicon and other conductive materials, manufactured in thin film layers. When sunlight strikes a solar cell, chemical reactions release electrons, generating electric current. Solar cells are also called photovoltaic cells or “PV cells” and can be found on many small appliances such as calculators. Albert Einstein was awarded his Nobel Prize for the discovery of what is known as the “photovoltaic effect” that is now used in all solar cells used to generate electricity.
Solar Photovoltaic (PV) System Components
Individual PV cells are arranged to form an individual PV “module” often called a PV panel. Then the modules are grouped together to form an array. The arrays are then combined and transfer their DC electricity to an inverter where it is converted to 240 volt AC electricity which is now ready to be used by your home or sent into your “reserve” for later use. This type of system is called a grid-connected system.
A stand-alone system uses the arrays and then stores the electricity for later use in a collection of batteries. These systems require a charge regulator or controller, an inverter to convert the battery stored electrical energy from direct current (DC) to the alternating current (AC) to be used by your home.
Both systems require wiring and mounting hardware or a framework. Some of the arrays are set on special tracking devices to follow sunlight all day long and improve system efficiency.
PV System Installation, Maintenance, and Longevity
You could install a photovoltaic (PV) or solar electric system yourself. For safety reasons and to avoid complications or injury, you will probably want to hire a reputable professional solar contractor with experience installing solar electric systems. While they are sophisticated electric systems, PV systems have few moving parts, so they require little maintenance. The basic PV module has no moving parts and can last more than 30 years while requiring little maintenance. The components are designed to meet strict dependability and durability standards to withstand the elements. The best way to ensure and extend the life and effectiveness of your PV system is by having it installed and maintained properly. Most PV system problems occur because of poor or sloppy system installation.
Sunlight Requirements for PV Systems
A photovoltaic (PV) system needs unobstructed access to the sun’s rays for most or all of the day to be effective. Shading on the system can significantly reduce energy output. Climate is not a major concern because PV systems are relatively unaffected by air temperatures. Abundant year-round sunshine makes solar energy systems useful and effective nearly everywhere in Florida.
The Size of Your Solar PV System
The size of your solar system depends on several factors such as how much electricity you use, the size of your roof, how much you’re willing to invest, and how much energy you want to generate. Contact an experienced licensed solar contractor to determine what type of system fits your needs.