How Do Solar Panels Work?

Posted on Jan 13, 2010 in Alt Energy, Tiny Homes, & Structures

How Do Solar Panels Work?

Shannon Bell

Using the Sun for energy is a concept that has been in existence for a long time.   The first successful, modern day experiments in creating solar electricity were conducted during the 1950s.  Your own calculator may have a small solar cell that enables the machine to work without batteries.  As conventional energy prices continue to rise and resources dwindle, more people are looking into harnessing solar energy by installing solar panels in their homes.

How do solar panels work?  Basically, they convert energy from the sun into electricity.  On any bright, cloud-free day, the sun projects some 1,000 watts of energy on a square meter basis onto the earth’s surface.  Although converting sunlight into electricity sounds like a simple concept, solar panels work in a specific and rather complex way.

The solar cells that are installed in devices ranging from calculators to street lamps and even your garden lights are called photovoltaic (PV) cells. They are composed of semiconductors like silicon.  Silicon plates are composed of millions of atoms.  However, they cannot generate electricity on their own, because they do not carry positive or negative charges.  To initiate the process of electricity, both positive and negative solar plates must be created. The chemical combination of silicon and phosphorus results in a negative charge.

Similarly, with the chemical addition of boron to a silicon plate, the plate will carry a positive charge.  When light hits a PV cell, the semiconductor absorbs a certain amount of that light. When negative solar plates are appropriately angled to the sun, the sun bombards the silicon and phosphorus atoms on the solar panel with photons. When this happens, certain electrons are set loose, permitting them to flow.

The negative solar plate is “sandwiched” with the positive plate, and the plates are attached to wires that then lead out and connect to a battery system or appliance.   The electrons released by the negative plate are attracted to the outer band of the positive plate. The electrons that are not used are essentially brought back to the silicon/boron negative plate, and the process of generating electricity restarts.

When this activity is conducted on a large scale, with plates positioned to attract maximum sunlight throughout the day, there can be sufficient electricity to run many types of electronic devices.  Typically, smaller scale projects will store that eletricity in a battery bank until needed.  This is true for solar garden lights and even the large panels mounted on residential rooftops.

Stay tuned for Part II of this solar series! 

 

About the Author

Shannon Bell writes for residentialsolarpanels.org, a non-commercial blog focused on her photovoltaic experiences to help people understand how and why they should save energy investing in solar power. She writes on Solar Panels for Homes to help people learn how to start consuming less energy and then apply those experiences to the next level.

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