Photovoltaic Energy

Renewable energies are the energies of the future. The world's population is growing and that is why energy consumption is increasing, consuming a large part of the planet's resources. The problem of all this is that we do not regenerate resources at the same time we consume them. Therefore, in the future, we may have serious problems if we do not use alternative energies. In this sense, it is important to use renewable sources whose use is unlimited.

What is photovoltaic energy and what does it consist of?

Photovoltaic energy involves the direct transformation of radiation from the sun's rays into electrical energy. To carry out this transformation, it is necessary to have solar panels, which is the main installation where the change takes place. The operation is simple. Basically, due to the solar radiation, the electrons of the device are activated, so that a small potential difference is achieved, which arrives through a semiconductor device, with which the energy is obtained. Once we have this, we need to condition and transform the current generated for its discharge into the network or its use in our home.

How does photovoltaic solar energy work?

To understand how photovoltaic energy works, it is necessary to understand the photovoltaic effect. This effect occurs when a photon (light particle) hits an electron. This electron is the one in the last orbit of a silicon atom.

If the energy obtained by the electron exceeds the force of attraction available to the nucleus, it will leave its orbit and be released from the atom. It can then travel through the material. In this case, the silicon will have served as a conductor, managing to direct this energy. The space left behind by the freed electron will later be occupied by another atom. This whole process will lead to a series of movements that will produce the well-known electric charges.

Photovoltaic generator

A photovoltaic generator is an association of photovoltaic modules that are connected in a certain way according to the required application. Each solar panel is made up of a series of photovoltaic cells, connected in series. This is why the greater the number of cells or solar cells, the higher the voltage (measured in volts) we will have for this application.

If we connect several panels in series, we can obtain a greater amount of electrical energy, increasing the voltage and maintaining a constant current. On the other hand, if we make a parallel connection of several branches of modules, the intensity will be this number of branches multiplied by the intensity of the module.

It is obvious that the more receivers we have, the more energy we will be able to transform. The electrical energy obtained, in the form of direct current, can be used directly, for example, in autonomous installations, or transformed into alternating current. This alternating current, normally used at home, is obtained by means of the photovoltaic inverter.

Components of a photovoltaic system

The elements of a photovoltaic system depend on the type of application in which it is used. That is, whether it is an application such as a grid-connected photovoltaic plant, a stand-alone photovoltaic system or a solar pumping system.

Grid-connected photovoltaic plant

In a photovoltaic plant, the main elements that can be found are the following:

- Photovoltaic panel. The basis of any photovoltaic installation.

- Solar tracker. In many photovoltaic plants we can find a solar tracking system. Its function is to maximize the production of photovoltaic modules. To do this, it performs a tracking movement to the sun throughout the day.

- DC connection wiring. The DC wiring is the element that transports and distributes the generated electrical energy. In this case, in the direct current part of the installation. This wiring goes from the solar panel itself, connecting the different modules, to the solar inverter. For this, there are different configurations. Basically, the logic of the wiring is to start with many cables and group them by means of elements such as accumulative boxes. In this way, in each box the current corresponding to several groups of solar panels will be collected. From these boxes, another direct current cable will go to the inverter, which will admit a certain number of cables, depending on the design.

- Photovoltaic inverter. The photovoltaic inverter is the element that transforms direct current into alternating current. This means that the output of this device will give a type of current that can already be fed into the grid. In other words, by means of this transformation, after conditioning, it can be used for electricity supply.

- Transformer. The transformer is in charge of achieving the appropriate voltage level to be fed into the grid.

- Medium voltage switchgear. It is a protection element that connects the photovoltaic installation to the electrical grid.

- AC connection wiring. Similar to the previous wiring, it basically connects the inverter with the transformer, as well as the transformer with the medium voltage cells.

Stand-alone photovoltaic installation

In an autonomous installation, the main elements are the following ones:

- Solar panel.

- Accumulator or battery. It stores energy for use at any time, being rechargeable.

- Charge regulator. This device is responsible for preventing the battery from overcharging or over-discharging.

- Photovoltaic inverter. In case of using elements that require alternating current, this device must be used.

- Load. These are the elements that require the energy generated.

Photovoltaic pumping system

The pumping system has the objective of obtaining water from wells using photovoltaic energy. Here are its elements:

- Solar panels.

- Motor pump. It is a device that combines an electric motor and a water pump for its extraction.

- Coupling generator - motor pump. It is a device that helps the motor to work at the right working point according to the radiation and temperature of the moment.

- Hydraulic circuit. It is the set of additional elements used for water extraction, such as pipes.

- Water tank. It is the place where the extracted water is stored.

What types of uses can be given to them in industry and housing?

Due to the advantages of photovoltaic energy, more and more homes and industries are beginning to incorporate it by installing photovoltaic panels. The main reason why everyone is concerned about this installation, is to get a good saving on the electricity bill.

The technology is an aspect that plays in favor of the users and is that the current panels are much more profitable than those of 10 years ago. In this sense, science has advanced a lot and now we have photovoltaic panels that can have up to 25 years of useful life. Thus, both families and companies that want to install these panels in their business, will have to face the initial investment of the same. However, due to the number of years it lasts, the amortization will be quite fast.

These photovoltaic installations are an independent and isolated installation from the grid. This means that if at any time we need some extra energy, we can always resort to another type of energy source through which we can get it. In this way, it is also possible to use it as a supplement and not depend entirely on it, so that we are covered in all kinds of situations.

Based on this, there are many household appliances that today begin to use small photovoltaic panels with which they are fed for consumption. In this way, they do not depend so much on electrical energy. Thus, the consumption that arrives at the end of the month with respect to them, is much lower.

On the other hand, we can also use small devices in our daily life. An example is the solar charger, with which we can recharge the batteries of our cell phones, laptops or tablets without any expense and anywhere where the sun shines.

In addition, there are new projects that are based on this type of energy. A good example of this is the solar desalination plant, which is capable of obtaining fresh water from salt water through a series of processes. You can read more about it here.

Advantages and disadvantages of using this type of energy

Advantages of Photovoltaic Solar Energy

As we have mentioned above, the main advantage is the energy savings that we will get by installing these photovoltaic panels. It is an energy that is amortized fairly quickly, since it has a long life and allows us to save a good amount of energy expenditure.

In addition to ourselves, it is an energy that is good for the environment. First of all because it does not pollute, it is a clean energy and besides that, it is silent. Noise pollution produced by other types of energy will not be a problem with photovoltaic energy.

It has a minimum maintenance. Thus, any task that we have to carry out or repair, will be less expensive than in any other installation and can be fixed quickly and easily.

The disadvantages of this energy

However, although it has a number of advantages, it is also possible to attribute some disadvantages. We have mentioned that it is an energy that pays for itself over time and is cheap, but nevertheless, the initial investment is high.

In addition, it is also necessary to have the necessary space to place the photovoltaic panels. Depending on the amount we intend to generate with this energy, we will need more or less space. If we live in a house in the countryside, we will probably have no problem. If, on the other hand, we live in an apartment in the city, things are a bit more complicated.

Finally, solar radiation is not always a fixed constant. There are days or times of the year when there may be a little less and this ends up being noticed in our ability to produce energy. Thus, as we have mentioned above, it is best not to depend exclusively on this type of energy and to be able to rely on other alternatives, in case we need them when the time comes.