PHOTOVOLTAIC SOLAR PANELS

Photovoltaic solar panels are the key element in the conversion of solar energy into electricity.

Photovoltaic panels have for several years experienced an accelerated reduction in costs that, in a short time, can lead the approaching energy revolution.



In the following image gallery you can find more information about photovoltaic solar panels.

The renewable energies, with a great development in countries like Spain, Chile, Argentina, Mexico, etc. have a great demand of photovoltaic solar panels.

The energy of the sun is a clean and inexhaustible energy. Among its many applications, is the use to obtain hot water, support in heating and air conditioning, and electricity generation.

Below you can find information related to solar photovoltaic panels, simply click on the images and access all the information.


PHOTOVOLTAIC SOLAR PANELS

In this article, we will see what types of photovoltaic solar panels exist, what are their main characteristics to compare and use one or the other, and what types of connection can be made between them.

In recent years, solar photovoltaic technology, i.e. the manufacture of solar panels or tamièn called solar plate, has achieved great development worldwide.

What is a photovoltaic solar panel?
What are photovoltaic solar panels?

A photovoltaic module is a panel consisting of a set of solar cells, which directly convert the photons of sunlight into electricity.

The production of current depends on the irradiance (level of illumination), so that the more light is captured, the greater the electrical intensity through the cell.

In the photovoltaic solar panel, the set of cells are electrically connected to each other, encapsulated and mounted on a support structure or frame.

The types of photovoltaic solar panels are given by the technology of manufacturing the cells.


How does a photovoltaic solar panel work?

PANELES SOLARES FOTOVOLTAICOS

As soon as sunlight reaches the solar panel, the electrons are “detached” from the top of the panel under the influence of this radiation; there is a free electron with a corresponding hole.

Because an electric field arises at the interface due to an uneven charge distribution, electrons can only go in one direction.

As a result, there is a voltage difference between the top and bottom of the panel. If you connect the top and bottom, a current will flow through the cable.

Because the voltage through the solar cell is very low (only half a volt), many solar cells are often “soldered” together in a solar panel.

Watch the video and learn more about how solar panels work

¿WHAT ARE THE DIFFERENT TYPES OF PHOTOVOLTAIC SOLAR PANELS?

What types of solar panels are there? Before deciding to install a solar installation on the roof, it is recommended to go deeper and see different types of solar panels.

The solar panel you choose will depend on your wishes, your budget and the surface of your roof (and the type of roof). You can think about the price, the quality of the panels and the performance you can achieve annually.

The type of panel is mainly determined by the material from which the solar cells are made.

The most common panels are made of silicone. These are monocrystalline and polycrystalline solar panels.

Amorphous silicon, also called thin film, solar panels are available. The newest type is glass and glass solar panel.

1) Monocrystalline solar panel

The solar cells in a monocrystalline solar panel consist of a crystal.

The surface of monocrystalline solar cells has ordered electrodes and is uniformly black/dark blue.

These solar panels have the highest efficiency. Monocrystalline solar panels have a higher percentage of yield than polycrystalline ones.

However, the panels are more expensive, but have a higher yield per m2. In short, the best option for homeowners who want to get the maximum performance if they have a house with a small roof.

2) polycrystalline solar panel

In a polycrystalline solar panel there are solar cells consisting of several thick crystals.

A polycrystalline solar cell shows a type of broken fragment pattern. Polycrystalline solar panels are favorably priced and offer reasonably high efficiency.

They are slightly less efficient than monocrystalline solar panels. When the roof space does not play a role, the polycrystalline solar panel type is the best choice because it will be much cheaper to compare it with the monocrystalline variant.

Option because it will be much cheaper to compare it with the monocrystalline varian

¿What is the difference between a photovoltaic solar panel and a solar collector?

The difference between a solar collector and a photovoltaic solar panel or a photovoltaic panel is that a solar collector heats water or other liquid, something that a photovoltaic panel does not do.

A solar panel consists of photovoltaic solar cells that are mounted on a panel. These solar cells convert sunlight into electricity. That electricity is called photovoltaic (PV) solar energy or solar energy.

¿Do photovoltaic solar panels help the environment?

The process by which solar energy is converted into electricity is 100% friendly to nature, as no harmful gases or particles are released.

Since 2010, photovoltaic solar panels have supplied electricity to more than 100 countries.

It is also the fastest growing power generation technology in the world. Between 2004 and 2009, the capacity of the grid-connected solar panel increased by an average of 60 percent annually.

¿What is the efficiency of the photovoltaic solar panel?

The efficiency of a photovoltaic solar panel is the part of the solar light energy that can be transformed into electricity.

This part is expressed as a percentage. The efficiency of a solar panel of this type is not one hundred percent because sunlight is composed of different colors and because a solar cell is generally made of a particular material that is not equally sensitive to all colors.

Part of the sunlight is therefore even straight. This means that a solar cell works optimally for a single color of light, the other colors are not absorbed and are therefore not used or only partially used.

Approximately 55% of the energy in light is lost in this way. That means only

Las mejores células solares pequeñas son prácticamente inasequibles y tienen una eficiencia del 25% en el laboratorio. En la producción comercial se consigue del 6 al 16%.

Esto se debe a que los materiales utilizados en la producción comercial son más baratos (porque son de menor calidad y tienen una sensibilidad de color por debajo de lo óptimo) y porque los procesos de fabricación son más baratos.

La eficiencia de una célula solar se puede aumentar al mejorar la sensibilidad del color al apilar dos o tres materiales diferentes, conocido como tándem.

Las pérdidas de color se limitan entonces de 40 a 45% en lugar del 55% mencionado anteriormente, dejando solo de 55 a 60%.

¿What is the useful life of a photovoltaic solar panel?

Photovoltaic solar panels for life.

The useful life of a photovoltaic solar panel is determined by the quality of the solar panel and the type of silicon used in the solar panel.

The average useful life is between thirty and forty-five years for a solar panel with crystalline cells and for a solar panel based on amorphous silicon, the useful life is between five and fifteen years.

A solar panel is easy to replace when it stops working.
Due to the strong technical evolution of recent years, the lifetime of a solar panel is constantly being extended.

¿What is the warranty period of solar panels?

The manufacturer’s warranties vary up to 25 years. Solar systems should last at least as long, so look for an installer who offers a warranty for that period of time.

The solar panels we have chosen for our test have 25-year performance warranties (generally guaranteeing that the panel will continue to produce at least 80% of its declared rated power after 25 years) plus a 10 to 12-year warranty for the product itself. .

An installer can also provide warranties for mounting frame, labor, etc. Sunpower is an exception, with a 25-year warranty for performance and product, and a higher performance criteria in the warranty.

¿What are the advantages and disadvantages of solar panels?

¿What are the advantages of solar panels?

  • Solar energy is free energy!
  • Solar panels provide clean and green energy.
  • PV works even in cloudy weather conditions.
  • Custom modular energy can be sized for any application.
  • The operation and maintenance costs of photovoltaic panels
  • are considered low, almost negligible, compared to the costs of other renewable energy systems.
  • Minimum maintenance requirements: Make a solar add-on and start saving.
  • Photovoltaic cells are completely silent and have no mechanically moving parts, they are a perfect solution for residential areas.
  • Solar panels are a very promising future for economic viability and environmental sustainability.
  • Solar energy can be available almost anywhere there is sunlight.
  • Photovoltaic solar energy is environmentally friendly, as when solar panels generate electricity, no emissions are emitted.
  • Installation costs can be reduced with the automatic solar installation kit.

¿What are the disadvantages of solar panels?

The intermittence and unpredictability of solar energy due to the climate cause the solar panels to decrease.

Solar panels require additional equipment, such as inverters to convert direct electricity (DC) into alternating electricity (AC) for the national grid to transmit and use.

Photovoltaic panels require not only inverters but also storage batteries, which significantly increases the cost of installing solar panels.

Large areas are required for large-scale photovoltaic solar projects or ground mounted commercial photovoltaic systems.

Efficiency levels of solar panels vary, but are relatively low, between 14% and 25% compared to efficiency levels of other renewable energy systems, such as LED lighting.

How are photovoltaic solar panels connected?

All photovoltaic modules have positive (+) and negative (-) poles on the back for connection and wiring. Remember that the photovoltaic solar panels are prepared to generate direct current, which will be transformed into alternating current by means of inverters.

There are two connections that can be made in a photovoltaic installation: Serial or Parallel. Let’s see with some examples what their characteristics are.

Series of connection of photovoltaic solar panels

Connection of two photovoltaic solar panels of Voc 22.42V and short-circuit current Isc 8.45A

 

PANELES SOLARES FOTOVOLTAICOS

Series of connection of photovoltaic solar panels

Connection of two photovoltaic solar panels of Voc 22.42V and short-circuit current Isc 8.45APANELES SOLARES FOTOVOLTAICOS

As we can see in the image, the negative pole has been connected to panel nº1 with the negative pole of panel nº2, as well as with the positive pole with the positive pole.
If we connect a multimeter to the output, we will obtain the following:

Total vacuum voltage: Voc = Voc1 = Voc2 = 22.42 volts

Short circuit current: Isc = Isc1 + Isc2 = 8.45A + 8.45A = 16.9A

Therefore, in a parallel connection, the currents are added and the resulting voltage is that of one of the panels (they must have the same characteristics).

¿When are series or parallel connections of photovoltaic solar panels used?

Depending on the size of the photovoltaic installation, the working voltage of the batteries (in the case of isolated self-consumption), the output voltage to the inverter (in large installations), one or the other will be used, or the combination of both.

Example of an isolated mountain refuge.

In an isolated installation in a mountain shelter with two 12 V photovoltaic solar panels and 12 volt accumulation batteries, the connection would be in parallel, as Vpanel1 = Vpanel2 = Working battery voltage = 12V.

Example of administrative building.

In an installation of an administrative building with 2,000 m2 of cover and self-consumption to support the air conditioning:

Estimated power of the air conditioning support = 10.560 W

Power panel Pmpp = 240W.

Panel voltage Vmpp = 28.75V.

Panel Intensity Impp = 8.35A

Solution

Due to the limited width of the roof, the following design is planned:

Series

Group nº1 of 21 photovoltaic solar panels in series with total voltage = 28,75V / panel x 21 panels = 603,75V

Group 2 of 21 photovoltaic solar panels in series with total voltage = 28.75V / panel x 21 panels = 603.75V

Current output group Nº1 = 8,35A

Current output group No. 2 = 8.35A

Parallel

Connection of groups nº1 and nº2 in parallel:

Voltage to inverter  603, 75 volts

Current to inverter 8.35 A + 8.35 A = 16.7 A

Como nota final, observamos que dependiendo de la conexión, la intensidad es pequeña o alta, con la consecuente implicación en las secciones de cable.