Solar Basics

by Gabrielle Hance

For novices and experts alike, a good knowledge of basic solar energy terms and abbreviations is a necessity. So, If you are thinking about making solar energy a bigger part of your life, whether in solar panels, water heaters, or any other solar devices, the next step is to familiarize yourself with the basics!

1.  Solar energy use can be either passive or active.

Passive solar energy uses the sun to heat up open spaces or metal tubes filled with water. Active solar energy involves a chemical reaction in photovoltaic (PV) cells, which make up modules.  Groups of modules are referred to as PV arrays.

2.  Terms in more Detail

Individual PV cells are electricity-producing devices made of semiconductor materials and come in many shapes and sizes.  PV cells are connected together to form PV modules, which are usually approximately 0,5 x 1 m2 and 0,33 x 1,33 m2 and made up of about 36 cells.  Modules are then combined and connected to form PV arrays of different sizes and power.

3.  Active Solar Energy Explained

The sun’s energy hits the PV cell and is absorbed into a semi-conducting material, such as silicon. Electrons in the silicon are knocked loose from their normally rigid structure and move through the cell, creating a one-way flow of direct current that can be used to power electrical devices.  Direct current is a straight flow of energy from one source to another.  Alternating current is capable of changing direction, and is used in residential areas. Because of this difference in current, an inverter is used to safely transform direct current into alternating current.

The electric current that is produced for power is measured based on watts (w)One watt is equal to one joule of energy per second (a very small measure of electricity) flowing in a current in a particular instant. Higher measures of watts include kW, kilowatts, equal to one thousand watts per second. Kilowatts are used to describe the energy flow of systems such as engines and residential heating and air conditioners.

4.  How to read your electric bill

When you get your electric bill, the payment amount is equal to the amount of kWh, or kilowatt-hoursconsumed multiplied by the price per kWh. Solar energy production works the same way. One kilowatt-hour is equal to one thousand watts of energy used in one hour, so the amount of solar energy that is created can be measured quickly and easily. If you produce enough solar energy, you may even be able to sell some energy back to the electric grid and make money!

Solar energy might seem confusing for the beginner, but some motivation and a starting point are all you need to begin learning about solar power.  The U.S. Department of Energy Efficiency has great educational resources for you! Also check out our FAQ’s for even more information.


To learn more about solar, check out the resources on our Helpful Links page.