What are solar cells used for?

Solar cells, otherwise known as solar photovoltaic cells are devices that convert solar energy into electricity. Solar cells are also referenced as devices that specifically capture the sun’s energy.  

Solar  cells have been around for a long time but as the demand and technology increase the complexity too increases.

For a number of years solar cells have been used in devices such as calculators eliminating the need for batteries. Solar panels have been used on emergency road signs, call boxes and parking lots that will power the lights.

Although the solar panels described may not be as abundant as calculators, they are becoming more common. As we face economic crisis, energy crisis and environmental crisis including global warming the turn to sustainable and clean power sources will continue to grow.

A topic of conversation that can be heard today is related to a solar revolution. This gives us the hope of future free electricity from the sun. This dream can be a reality as the technology and demand increase.

The sun offers about 1,000 watts of energy per square meter of the Earth’s surface.

If we were able to harness this energy we would be able to power all of the homes and businesses with electricity for free.

Understanding how a solar cell actually works to harness the sun’s energy will help us move forward into the solar revolution.

The solar cells used in calculators, homes and satellites are photovoltaic cells or modules. A module is simply a group of cells that are electronically connected. Photovoltaic cells do just what the name implies: photo meaning light and voltaic meaning electricity.

Solar cells are made from a semiconductor such as silicone and when light hits the cell it is absorbed within the material. The energy absorbed knocks electrons loose to flow freely.

The cells also have electric fields to force the electrons to flow in a specific direction; this is called a current. The placement of metal contacts on the cell allows the collected energy to be used outside of the cell such as in solar calculator.

It is the combination of the built in current and the electric field that determines the wattage that the cell will produce.

A solar cell, as simple as it may perform, is structured in layers that include from bottom to top: a back contact, P-type silicone, N-type silicone (apposing to create an electric field), a contact grid, anti-reflective coating and a glass cover to protect the cell from the element. 

To power your home with the sun you will need to have a solar photovoltaic array with the proper orientation to the sun for your location. A unit that will actually track the sun will have the best performance; however, if you are located in the northern hemisphere facing the array at true south with the angle of your location’s latitude should suffice.

To fully power your home you will need to be able to store the energy collected from the sun and this is done with batteries.

Alternativly you can (with permission) hook your array up to the power grid and sell your extra power to them and in turn receive back power at night orcloudy days. Essentially you use the power company as a storage facility.

If you are using batteries you will also need to use an inverter that can convert the DC power of the batteries into AC power that your home will use.

Although perhaps a little complex in the beginning the end result is a long lasting sustainable and clean power source that starts paying for itself from the first use.