The Photovoltaic Solar Cell - How Solar Cells Create Energy from Freed Electrons

Photovoltaic solar cells convert sunlight directly into electric power. They were once exclusively used on space satellites to tap into the readily available power of the sun, an unlimited energy source. Photovoltaic cells are made from semiconductor materials like silicon, which is used in 95% of solar cells produced worldwide. The cells convert sunlight into energy by taking a portion of that sunlight and absorbing it. Electrons are then knocked loose from the absorbed energy and freed. These freed electrons flow as a current. Subsequently, using metal contacts on the top and bottom of the Photovoltaic cells draw electricity from this current. The energy produced can power devices directly or in some cases, the energy is stored in rechargeable batteries.

A group of Photovoltaic cells form a module in a solar panel. Subsequently, a group of solar panels that are interconnected are called an array. An array can be designed to reach the needed peak direct current (DC) voltage. When Photovoltaic cells are connected like this, they provide a higher voltage and produce more electric current. Typical power ratings of solar modules are from 10 Wpeak to 100 Wpeak.

Since Photovoltaic solar cells only work in the daytime and optimal only on clear days when sunlight is available, the Photovoltaic cells work best when combined with batteries to store the energy they produce. While the solar cells can last a lifetime, the batteries have a shorter life and are therefore an additional cost. By attaching the Photovoltaic system to a utility grid, solar-powered homes and businesses can use conventional electricity alongside solar energy. The solar energy can be used when needed or available. It can also be sold back as well when the Photovoltaic system produces more than needed. In comparison, batteries used with Photovoltaic systems need to be replaced regularly.

You will probably be most familiar with the Photovoltaic solar cells (a miniaturized version) that power your solar-powered calculator. However, you can also spot them on rooftops in many urban, suburban, and even more in remote areas. Remote areas can especially make use of solar power due to the inaccessibility of nearby fossil fuel suppliers or power connections. While installation of a Photovoltaic solar power system can be quite expensive, it will more than pay for itself in terms of energy savings in as little as two years. In addition, they have no moving parts that need to be maintained or repaired. They also do not give off emissions so they don't produce waste byproducts.