Solar Panels

How do solar panels work?

Solar panels are made up of many small units called photovoltaic cells or solar cells. Photovoltaic cells are responsible for transforming light energy into electrical energy through the photoelectric effect. In this way, many cells connected to each other from a solar panel.

The technology for transforming energy from the Sun for human use is one of the most notable innovations in recent history, since it is a renewable alternative to fossil fuels, despite its shortcomings. 

Solar panels are a promising source of energy, solar panels crown the roofs of our homes, solar panels illuminate traffic signs, even help to maintain power for spacecraft. But how do solar panels work?

Briefly explaining it, a solar panel works by allowing photons or light particles to hit the electrons to free them from the atoms, thus generating a flow of electricity. 

Photovoltaic cells are covered by a semiconductor material r (almost always crystalline silicon ), the same material that is used in other fields such as microelectronics. In addition, for photovoltaic cells to work it is necessary to create an electric field. 

Electric fields are produced when opposite charges separate, that is, positive and negative charges. Therefore, to achieve this field, manufacturers add other materials to silicon to achieve a certain charge.

Each photovoltaic cell is basically a sandwich made up of two slices of semiconductor material, usually silicon, the same material used in microelectronics.

To work, photovoltaic cells need to establish an electric field. Like a magnetic field, which occurs due to opposite poles, an electric field occurs when opposite charges separate. To achieve this, manufacturers “dope” silicon with other materials, giving each slice of the sandwich a positive or negative electrical charge.

Specifically, the seed phosphorus on the top layer of silicon, which adds additional electrons, with a negative charge, to that layer. Meanwhile, the lower layer receives a dose of boron, resulting in fewer electrons, or a positive charge. All of this adds up to an electric field at the junction between the layers of silicon. So when a photon from sunlight hits a free electron, the electric field will push that electron out of the silicon junction.

Solar Panels: Positive and negative charges

Among other materials, professionals add phosphor to the top layer of silicon. This gives you additional electrons with a negative charge. On the other hand, the lower layer receives a dose of boron. It produces fewer electrons and a positive charge. In this way, it is achieved that the solar cells connect two charges and, therefore, can generate electricity.

When a photon in sunlight releases an electron, the electric field sends it out of the silicon, allowing the electrons to be converted into electrical energy. In addition, solar panels are metal conductors, so at that point, the energy is transferred to the cables and flows like any other source of electricity.

A couple of other components in the cell convert these electrons into usable energy. Metallic conductive plates on the sides of the cell collect the electrons and transfer them to the wires. At that point, the electrons can flow like any other source of electricity.

Recently, researchers have produced ultra-thin and flexible solar cells that are just 1.3 microns thick, about 1/100 the width of a human hair, and 20 times lighter than a sheet of office paper. 

In fact, the cells are so light that they can sit on top of a soap bubble, and yet they produce energy as efficiently as glass solar cells, scientists reported in a study published in 2016 in the journal Organic Electronics. Lighter, more flexible solar cells like these could be integrated into architecture, aerospace technology, or even wear electronics.

Other types of solar energy

Currently, we can find many types of solar energy, such as solar thermal energy or concentrated solar energy (CSP). However, although they work differently from photovoltaic solar panels, they all take advantage of solar energy both to produce electricity and to heat water or air.