Solar Panels

To help clear up some confusion, in this article we will discuss the basic types of solar panels.

Types of Solar Panels

There are basically two types of solar panels.

Thermal Collectors: use the sun's energy to heat water or another fluid such as oil or antifreeze.
 

Solar Cells: also known as photovoltaic cells or modules that use silicon cells to convert light from the sun into electricity. Photovoltaic is often abbreviated as "PV".

The thermal collector type has been around for a long time and uses materials that are more commonly available. Solar cells utilizes manufacturing processes and materials which are expensive and not widely available.

Which type you use will depend largely on what type of energy you need, but size and capacity requirements, as well as cost will also factor in. If you simply need to heat something up, such as the air or water in your home, you'll likely use solar panels. If, on the other hand, you need to power an electric appliance or vehicle, you'll need to use solar cells.

Thermal Collectors
 

This is what most people are referring to when they use the term "solar panel".  These are mainly used to provide hot water and heating for homes. With advances in technology, this has become a quite effective system. Only about 10 to 12 square meters of solar panels are needed in order to provide both the heating and the hot water required in a typical home.

This type of solar panel consist of tubes which allow water to run through them. The tubes are connected to a metal sheet which collects the heat of the sun, in order to warm up the water running through them. They are usually encased in an insulated box which helps retain the heat. This type of system is frequently installed on the roof.

Different combinations of metal are used in order to improve the efficiency of the unit. Copper and Aluminum are common metals used in this system. Since this type of system uses commonly available materials and is not too difficult to build, many people build their own. See the column to the right for some resources that will help you build your own system.

You might think that a hot climate would be required, to make this system work. Surprisingly, this system is mainly in use in northern countries such as Sweden, Denmark, Germany, and Switzerland. All of these countries have relatively cold climate.

Click here to learn how to make a thermal collector solar panel.

Solar Cells

These types of solar panels capitalizes on solar energy by converting sun rays directly into electricity. This is achieved by using materials called "semi-conductors" (the same materials that are used to make computer chips). When sunlight strikes these metals, one side becomes positively charged and the other side becomes negatively charged. This causes an electrical flow similar to that of a small battery.

The basic unit in a PV system (photovoltaic cell) is a small piece of semi-conductor ranging from about 1 centimeter to 15 centimeters in size, depending on the application. This unit is called a solar cell. A single cell does not create a lot of electricity. Usually, several cells are arranged and connected together into what is called a "module" (or what most people refer to as a solar panel).

The number of cells connected in a module or panel determines how much electricity is produced. In order to increase the amount of electricity produced, several modules may be connected to each other. When this is done, it is called a "solar array."

Since a single solar cell produces only about half a volt, you would need about 24 cells in a panel in order to produce a 12 volt charger which can power most small electrical appliances. With the right type of panel or combination of solar cells, you can power just about any electrical device.