How do solar panels work?

Solar panels are the key to playing an active role in the production of renewable energy and in the energy revolution that has been developing in recent years. Do you want to understand how photovoltaic panels function and transform the sun’s energy into clean electricity to power your home?

Let’s take a look at how solar energy is generated step by step.

How does a solar panel work?

First of all, “solar panel” is a broad term. It can refer to two different kinds of system:

• photovoltaic (PV) solar panels: their primary function is to produce electricity, but they can also produce thermal energy if combined with a latest-generation heat pump;
• thermal solar panels: these allow thermal energy production by increasing the temperature of a liquid, usually water, which flows from the panels on the rooftop to the domestic heating system.

The former is the most popular for domestic installation. A photovoltaic panel consists of many photovoltaic cells connected to each other: it is the photovoltaic unit that turns sunlight into electricity. Photons, the “particles” provided with energy from the electromagnetic waves of sunlight, stimulate silicon atoms, which release electrons and thus generate an electrical flux. How?

A photovoltaic cell is typically a multilayer silicon unit capable of transforming and conducting energy thanks to the opposite charges generated by the photovoltaic effect in the semimetal. Solar panel manufacturers are able to create this effect thanks to doped silicon, a semiconductor material modified by small amounts of atoms of other materials that can provide a positive or negative electrical charge for each side of the unit.

The two materials most commonly used to dope silicon in a common photovoltaic cell are:

• phosphorus, in the upper layer of silicon: this has a negative charge, so it adds more electrons to the layer
• boron, in the lower layer: this generates fewer electrons and therefore contributes to achieving and maintaining a positive charge when the solar cell is exposed to sunlight.

The doped silicon therefore allows the creation of an electromagnetic field ready to receive sunlight. The photons, like billions of ping-pong balls, hit the panels and excite the free electrons in the cell; the electric field created in the panel pushes these excited electrons out of the silicon unit towards the grid. The typically silver metal plates, placed on the sides of the solar cell, capture the electrons as electrical energy, transferring them via electrical wiring. Of course, there are different cell structures and architectures, but the basic principles of operation are common to all.

Solar panels generate DC (direct current) electricity, which is transformed into AC (alternating current) at the appropriate voltage by the system’s inverter. In this form, the electricity generated by a PV solar system can be used directly in the homes and businesses connected to the solar panels or fed into the national grid. Have a look at our article to find out which are the most effective methods to manage excess energy.

The advantages of solar power and solar panels

Solar panels and photovoltaic cells offer many advantages to energy users, whether they supply homes or business.

Installation

Solar panels can be very quickly installed in a wide range of locations. It is quite common to see them on the roofs of country properties, but also in residential neighbourhoods or urban centres, e.g. on the roofs of apartment buildings that can share the benefits of these systems. In addition, the installation of solar panels is not intrusive, because it does not alter the aesthetic appearance of your home.

Safety

Solar panels can be considered very safe: since they are mostly composed of single silicon units connected to each other, there is no danger of leakage or emission of toxins or fumes. In addition, photovoltaic panels produce electricity without generating noise pollution: this is an important advantage when thinking about clean energy.

Duration and maintenance

Solar panels have a long service life and require very little maintenance. It is important to clean them periodically (depending on pollution levels in the area) and keep them free from dirt.

Disposal

If you want to decommission the system at the end of its life cycle, in the case of a non-integrated system everything will be exactly as before in no time. In the case of a partially roof-integrated system, it will simply be necessary to restore the roofing tiles. Read more in our article on integrated photovoltaics. In any case, panels can be disposed of in a completely sustainable way and without any impact on the environment.

Energy saving

Of course, solar panels can reduce electricity bills in the short term, and they become an excellent source of energy and long-term economic return when the cost of purchasing and installing solar cells is refunded.

Solar panels guarantee the user a continuous energy supply when the sun is shining, a benefit that continues even when it is cloudy because the panels also capture diffused sunlight.

Storage and sharing

Last but not least, solar energy users need to consider storing electricity and distributing it to neighbours or feeding it into the national grid. The production of energy in excess of their own consumption offers the possibility to accumulate energy with a storage system for times when the system is not able to produce it, such as at night.

Whether you are equipped with a storage system or not, it is also possible, with the help of Regalgrid, to share this energy with other consumers within your Energy Community thanks to a smart grid for decentralised energy distribution. Find out how it works by reading our article on smart grids.

This also helps those who cannot install a system due to the cost or a lack of space, offering an alternative energy source to fossil fuels. Sunlight is an unlimited energy source and is also “green”, as it does not release pollution into the air.

Understanding how a photovoltaic system works and the benefits of producing and sharing clean energy within a localized energy model allows you to jump to a future that has already begun: a digital energy future, as promoted by Regalgrid.