Solar Panel

What is a Solar Panel?

A solar panel, also known as a photovoltaic module, is a large panel of semiconducting materials, glass, and metal that generates power from the sun through the photovoltaic effect.

Key Takeaways:

  • Solar panels are made up of several smaller solar cells that, when connected, are able to generate power at a much higher rate than on their own.
  • Solar panels use the photovoltaic effect to generate an electrical current from the sun’s light.
  • Solar panels are made up of several layers that include a semiconducting component, a conducting component, and several layers that serve to protect the panel.

Understanding Solar Panels

A solar panel is made up of one or more photovoltaic cells that are networked together and installed in a frame to generate electricity from sunlight through the photovoltaic effect. Solar panels are made from two special types of semiconducting materials called p-type and n-type materials that generate an electric current when exposed to light.

A collection of solar cells is called a solar panel or module, and a collection of one or more solar panels is called a solar array.

To illustrate:

One or more solar cells → One or more solar panels → A solar array

In most instances, a single solar panel is not enough to power most residential homes by itself, so by connecting many individual solar panels, a solar array will produce the higher desired power output.

Solar panels produce direct current power (DC) which is able to be used by some types of electronic devices, but which must be modified into an alternating current (AC) power for most home or business applications. This is why most solar panel installations also have an inverter installed nearby to convert the power before being supplied to electronic devices.

The wattage of a solar panel is determined as a product of the voltage and the amperage generated by the panel. The wattage rating of a panel (ie, a 1000 W Solar Panel) is rated by its DC output power under standard test conditions and will often vary from the actual power measured once the panel is installed.

How does a solar panel work?

Solar panels are made of two types of semiconducting materials called p-type and n-type semiconducting material. Each type of material is either (p)ositively or (n)egatively charged and when they are joined together, they create what is called the p-n junction. Or, to literally interpret, the place where p-type and n-type material touch. 

In this junction, an electrical field is generated where electrons move toward the p-side, and their counterparts, called ‘holes’, move to the negatively charged n-side.

When light of the right wavelength strikes the solar panel, energy from the photons is transferred to the electrons in the semiconducting material. This causes the electrons to jump up to a higher-energy state and leaves behind a ‘hole’ where the electron was previously. This movement creates an electrical current that can be collected by a conducting material.

What is a solar panel made of?

Solar panels are made of several layers that include a backing layer of plastic and aluminum, a conducting layer that collects the generated electrical current, the semiconducting layer that generates the electric charge, and a transparent layer usually made of glass that protects the solar panel from damage.

Polycrystalline silicon is the main semiconducting material that most solar panels are made of on the mass market. It is produced by the distillation of various silicon compounds at very high temperatures in a purification process called the Siemens process.

To the naked eye, polycrystalline silicon appears to have large crystals known as crystallites that give it a very distinctive appearance. When used in solar applications, polycrystalline silicon solar panels are the most common type of solar panel due to their lower cost than monocrystalline silicon. Between 2008 and 2013 the total number of solar manufacturers producing polycrystalline silicon solar panels increased by more than ten times.

Related Terms

Solar Cell – A solar cell is the colloquial term for a photovoltaic cell which converts solar energy into direct current electricity for use in homes or businesses through the photovoltaic effect.

Photovoltaic Panel – A photovoltaic panel is one or more photovoltaic cells that are interconnected to generate electricity from light through the photovoltaic effect. Also known as a solar panel.

Photovoltaic Module – A collection of photovoltaic cells mounted together to collect sunlight for energy. Also, colloquially called a solar panel.