Solar panels explained
Simply put, a solar cell is a device that converts sunlight into electrical energy. Solar cells are made of photovoltaic materials or cells that are capable of absorbing sunlight and producing energy. The assembled solar cells consist of a strong aluminum frame and a tempered glass cover that protects the photoelectricity.
solar cell parts
Solar cells consist of several parts with different functions, including:
- Solar cells consist of photovoltaic (PV) cells that convert sunlight into direct current (DC). Most solar panels used on rooftops consist of 60 or 72 cells.
- The aluminum frame provides structural support and protection for the photovoltaic cells.
- A clear glass cover protects the panel's vestibule photocells without interfering with sunlight absorption.
- The backing , usually made of a durable polymer, covers and protects the back of the solar cells.
- The solar cell envelope uses polymer layers that separate the solar cells from the protective glass and back panel, providing additional protection.
- The junction box is located on the back of the PV panel and contains the electrical terminals used to connect several panels together.
How do solar panels work?
Solar cells are based on a physical principle called the photovoltaic effect. Solar cells are made of semiconductor materials that absorb the energy of photons, or "particles of light." The electrons in the photovoltaic material start moving when they receive energy, generating an electric current. A solar cell contains many photovoltaic cells connected together to increase the total power of the system.
Check out our guide to learn more about how solar panels work.
Types of solar cells
Crystalline silicon is the most common photovoltaic material. According to the US Department of Energy, 95% of solar modules today use silicon. There are two main types of silicone sheets.
- Monocrystalline solar cells are made from single crystals of silicon and have higher efficiency than other types of panels.
- Polycrystalline solar cells consist of several silicon crystals. Although polycrystalline panels are less efficient than monocrystalline panels, they are more affordable.
You can also find thin panels that use a thin layer of photovoltaic material instead of crystalline silicon cells. Thin film panels use other semiconductor materials such as cadmium telluride (CdTe) or copper indium gallium selenide (CIGS).
The following table compares the main characteristics of the three types of solar cells.
* Panel prices are based on market research, including architectural specifications . Your price may vary.
What is a solar photovoltaic system?
A solar power system converts sunlight into clean energy to lower your electricity bills. Solar technology also reduces your impact on the environment by generating renewable energy – you use less electricity than fossil fuel power plants.
parts of the solar system
Solar panels are the main components of a photovoltaic system, but you need additional equipment to use them as a power source for your home.
- Solar cells convert sunlight into electricity using the photovoltaic effect. The number of solar panels required depends on the power consumption and the size of the system.
- A solar inverter converts the output power of solar panels from direct current to alternating current (AC) needed to power your home appliances. You can connect the solar panels in series with a single inverter or equip each panel with separate small inverters.
- A racking system provides structural support for your solar panels, whether on the roof or on the ground.
- A battery system is an optional component that stores excess energy produced by your panels for use at night and on cloudy days.
- Circuit breakers protect the solar panels from electrical faults, shutting down the system within seconds if a problem occurs.
Types of solar energy systems
You can classify solar panels according to how they interact with the local power system.
- Solar power systems are always connected to the local utility grid and cannot operate during a power outage (unless you have a solar panel). Most residential solar power plants are connected to the grid.
- Off-grid solar systems are always off-grid and use solar panels for a continuous power source to charge the batteries.
- Hybrid systems are usually synchronized with the grid, but can also operate independently during a power outage. If your electric company charges for time of use, you can go off-grid to avoid higher kWh rates.
Energy storage is not required for grid solar systems, as you can use the grid when your home consumption exceeds solar production. On the other hand, energy storage is very important for autonomous and hybrid systems.
You can't use standalone solar panels as standalone power sources because their output is constantly changing depending on sunlight conditions. For example, solar panels can't produce electricity at night because the sun isn't shining, but you can get power from solar panels.
Solar supplement
According to SEIA, the solar energy industry in the U.S. has grown 24% annually for more than a decade. Solar energy systems offer financial and environmental benefits by lowering electricity bills and replacing fossil fuels with renewable energy. You can also use the power of solar panels to power other sources, such as electric vehicles (EVs).
Many renewable energy technologies are only applicable to large-scale applications such as wind turbines. But thanks to their modular design, solar panels are suitable for projects of any size, from solar farms to small residential systems. The best solar panels include a 25-year product warranty that covers maintenance issues for the lifetime of your solar panel, helping to ensure a return on investment.
Cost and Energy Savings of Solar Panels
The average cost of installing solar panels in the US is $2.85 per watt. So a 6-kilowatt solar system costs about $17,100 before solar credits, or $11,970 after the 30 percent federal tax credit.
The main factors that determine the amount of electricity your panels produce are overall system dimensions and local sunlight. Under favorable conditions, you can expect to generate more than 8,000 kWh of energy per year with a 6 kW system.
If electricity costs 15 cents per kilowatt hour, 8,000 kWh of solar energy can save $1,200 a year. With an initial price of $11,970, you can count on a payback period of about 7.5 years. If you buy quality solar panels with a 25-year warranty, you can get more than a decade of free electricity after recouping your initial investment. Many solar companies also offer warranties on system installation and operation.
minimum
Solar panels are devices that use solar panels to convert sunlight into energy. Home and business owners often use solar panels to generate clean energy and save on electricity costs. Some states, such as Vermont and New Jersey, have set clean energy goals and are encouraging the use of solar panels to reduce greenhouse gas emissions.
Solar panels can help you save hundreds of dollars in energy costs each year. In addition, incentives such as the federal solar tax credit can help you lower the initial cost of the system. However, solar panels only generate power on sunny days and cannot generate electricity at night. A solar installer can help you decide if solar is right for you, including optimal system sizing based on a professional assessment of your roof's condition and utility bills.
Leonardo David is an electrical engineer, MBA, energy consultant and technology writer. His experience in energy efficiency and solar consulting includes industries such as banking, textiles, plastics processing, pharmaceuticals, education, food processing, real estate and retail. Since 2015, he has also been writing articles on energy and engineering topics.
Tori Addison is an editor who has worked in the digital marketing industry for over five years. Her experience includes communications and marketing in the nonprofit, government, and academic sectors. A journalist by profession, he began his career covering politics and news in New York's Hudson Valley. His work covers local and state budgets, federal financial regulations, and health care legislation.
