What are solar panels?


 image of the first known solar panels
The first solar panels were affixed to a New York City rooftop by Charles Fritts. Image source: Smithsonianmag.com

Solar panels, or photovoltaic (PV) panels, convert solar energy from the sun into usable electricity. As far back as the late 1800’s, the potential for creating energy from the sun was understood. However, it was not until 1954 that solar cells were developed, leading to the creation of solar panels built from multiple solar cells. 

Solar cells convert sunlight into electricity through the photovoltaic effect, hence the name ‘PV panels’. The electricity that is generated can then be used to power your home, sent to the grid, or stored within your home solar battery system.

In this blog, we will cover a brief history of solar panels, how they work, the components that make up a solar panel system, and the cost of solar panels. 

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    A brief history of solar panels

    The photovoltaic effect, or the ability to generate electricity from sunlight via electrons, was first observed in the late 1800’s which then led to the invention of the first solar cell by Charles Fritts. 

    Solar panels were not commercially viable or truly efficient at absorbing and generating a usable amount of electricity until after the invention of high-silicon PV panels in 1954 at Bell Labs. 

    Throughout the 1970’s to early 2000’s, solar power was slowly embraced around the world. But it was slow to be incorporated within the United States due to its high cost. In the early 2000’s, government incentives began to make solar panel installations more attractive for homeowners and utilities. Simultaneously, the costs of solar panel production dropped, further reducing the price tag.

    Solar power is projected to be a key part of the renewable energy mix for the United States - the sun’s energy will never run out. Solar technologies are becoming more advanced each year and will help reduce emissions from fossil fuel plants by diversifying energy production.

    How do solar panels work?

    The most important component of a solar panel is the cell. A solar cell is what converts the sun’s energy into electricity. Solar cells are made up of crystalline silicon, which is photovoltaic, and are then protected by a sheet of glass to filter the sunlight before it reaches the cells.

    The most common types of solar PV panels are monocrystalline and polycrystalline, both of which are made with silicon that is melted and mixed with boron, which gives silicon its electrical capability. 

    The main difference between monocrystalline and polycrystalline panels is that the more-efficient monocrystalline is made from a single crystal silicon solar cell, while polycrystalline is made from melting several silicon crystals together. 

    Learn more: Pros and cons of monocrystalline vs. polycrystalline solar panels

    Many silicon crystals are then assembled, along with solar cells, to convert the sun’s rays into electricity, to form one panel.

    When exposed to sunlight, solar cells generate an electric current, direct current (DC) electricity, which is then converted to usable alternating current (AC) electricity through an inverter. This AC electricity is what powers your home, is stored in your solar battery, or sent back to the power grid. 

    What are solar arrays made of?

    Aside from solar panels, you need racking and mounting equipment and a solar inverter to create an entire solar power system. 

    what are solar panels

    Besides the solar panel itself, the key components of a solar panel system are the racking (either ground-mounted as pictured above or mounted on your roof) and the inverter which creates usable electricity from each solar panel. This electricity is then used to power your home. 

    Solar racking and mounting systems are what hold the solar panels in place, either on a rooftop or on the ground. There are even options that can track the sun to absorb as much sunlight as possible, although these cost more than is typically worth it. 

    Another key component to solar PV systems is the inverter. This is what changes the DC energy generated by the solar panel into usable AC electricity for your home. The inverter has three main roles:

    • To convert DC energy into AC electricity
    • To communicate with the grid
    • Act as a way to shut down your solar panels if there are any issues with wiring or other hazards 

    The inverter is the key part of your solar system, your solar panels would not produce power without it. 

    Your solar installer can help you determine which racking and inverter types make the most sense for your solar system. 

    How much do solar panels cost?

    Solar panels vary in cost depending on the size of the system you are installing, the type of solar panel installed, local and government incentives, and installation costs. 

    But, you can loosely estimate the cost of solar based on the average cost per watt of solar panels within the United States. As of April 2021, solar panels cost $2.85 per watt to install.

    The average size of a home solar panel installation is 6kW, which means this would cost you $17,100 before the 26% federal tax credit. But after that is applied, you would save $4,446! After installing solar panels, you can save even more and potentially earn money through net metering benefits

    The best way to determine how much solar panels cost and how much they can save you on your electricity bills, is to work with a licensed solar installer. They can determine how many panels are ideal for your home’s energy needs and provide warranties for their work for years to come.  

    Find out how much a solar panel system will cost and save you this year

    Key takeaways

    • The photovoltaic effect was discovered in the late 1800’s and led to a gradual increase in the use of solar panels. Today, solar is a major global electricity provider.
    • Using silicon solar cells, solar panels produce direct current (DC) electricity via a solar inverter, which converts it into alternating current (AC) electricity to power homes and businesses.
    • A solar system’s main components are the solar panels, solar racking, and most importantly, the solar inverter.
     - Author of Solar Reviews

    Ana Almerini

    Web Content Specialist

    Ana is a web content specialist at SolarReviews. She has 5 years of marketing experience blended with 2 years of experience in climate communications and holds a master of arts degree in climate and society from Columbia University. Ana frequently volunteers for environmental causes ranging from oyster reef restoration in NJ to expanding bike sharing in Naples, Italy.

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