An Introduction to Solar Panel Systems
Solar power technologies are expected to play a key role in the energetic revolution towards a sustainable and eco friendly world, along other renewable energy systems (from wind turbines to ground source heat pumps). These solar technologies are not homogeneous and their working principles vary from one another, but all of them share their energy source: the sun.
Those different functionalities when it comes to capture solar energy allow a broad classification of solar devices into two main categories: photovoltaic (PV) and solar thermal.
- Photovoltaic systems use the photovoltaic effect, that is, the physical phenomenon by which an electric current is formed in specific materials when exposed to sunlight, to turn solar energy into electricity.
- Solar thermal systems, in turn, are based on the heating of a fluid (water or water plus a refrigerant) by the sunlight. The heated fluid can then be used for producing electricity (in medium systems to big solar power plants) or heat water (small to medium systems).
Both photovoltaic and solar thermal systems are installed and employed in deserts and temperate climate areas across the globe. Nevertheless, their contribution to the total amount of energy produced in the world is still far from those of oil, gas or coal.
This post is focused on photovoltaic systems, also called solar panel systems. If you’re interested in getting quotes of solar panel systems, we offer you a quick, free of charge and without obligations services that will allow you to compare up to four different brands. The only thing you have to do is filling the form on the right.
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How a Solar Panel System Works
As stated above, a solar panel system is a device that creates an alternative current (AC) thanks to solar energy. The core components of the system are, thus, those where the process of transforming light into an electric current takes place.
They are called photovoltaic cells, and are made of semiconductive materials. Since the electric power produced by a single cell is very low compared to that needed for even household applications, cells are interconnected to form bigger units, called modules. These modules can, in turn, be connected to each other forming arrays.
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But these fundamental components are not enough for a solar panel system to work. A major issue is that the output current of a cell (or module or array) is direct current (DC). Since AC is the type of current utilised in the transport and distribution of electricity, a component, called inverter, has to be added to transform DC into AC. Other elements help to “condition” the current. Solar battery storage systems may be included to allow for the storage of energy.
Besides those electrical elements, mechanical components are also needed. Among them, the structures responsible for pointing modules toward the sun are specially relevant.
Solar Cells, Where the Miracle Occurs
Solar cells receive sunlight and produce a direct current thanks to it. The process by which this is possible is known as photovoltaic effect. It is based on a property of semiconductors by which, when solar rays impact a layer of these materials, some of the atoms (the more energetic ones) release electrons, creating a direct current.
A solar cell not only consists of the layer (or layers) of a semiconductor, but also a light control film, a glass layer, two encapsulating layers and an aluminium frame (this is the classic configuration).
Solar cells are often classified into traditional, second-generation and third-generation:
- Traditional solar cells are made from crystalline silicon (that includes mono and polycrystalline).
- Second-generation solar cells, also called thin-film, are made from amorphous silicon or non silicon materials (e.g. cadmium telluride).
- Third-generation solar cells are made from a range of new non silicon materials, such as conductive plastics. Some third-generation cells use plastic lenses or mirrors to concentrate sunlight on a small piece of high efficiency photovoltaic material.
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Final Considerations of Solar Panel Systems
The high popularity of solar panel systems, both at a small scale (when used for household purposes) and at a big scale (solar power plants) is justified by its green and renewable nature. But there are some practical reasons that also stimulate the employment of these systems:
- At a domestic level, they allow for a significant reduction of utility bills (solar energy is completely free), and even for the homeowner to be paid for using or selling the energy generated through a solar panel system (in the UK, that is possible tanks to the Feed-in Tariff).
- At a big scale, governmental incentives and the enormous potential of solar industry encourages the creation and development of companies in the sector.
Finally, we'd like to offer you a simple, quick, free and without obligations service that gives you the opportinity to compare different solar panel brands by just filling the form on the top right corner of this page.