Panels photovoltaic solar energy

Elements of a photovoltaic solar installation

Elements of a photovoltaic solar installation

The photovoltaic solar panel is the element that captures solar radiation and is responsible for transforming solar energy into electricity through the photovoltaic effect.

But in addition to the photovoltaic panel, the photovoltaic installations require a series of complementary elements that are necessary to guarantee the functionality, control and durability of the solar installation.

Main elements of a photovoltaic solar installation

Photovoltaic cell

The photovoltaic cell is the part of the photovoltaic panel responsible for transforming solar radiation into electrical energy thanks to the photovoltaic effect. The result is an electrical current in direct current.

Generally, a photovoltaic module or solar panel consists of an association of photovoltaic cells, encapsulated in two layers of EVA between a glass front sheet and a back layer of a thermoplastic polymer or another glass sheet when it is desired to obtain modules with some degree of transparency.â €

The photovoltaic cells most commonly used in photovoltaic panels are silicon, and can be divided into three subcategories:

  • Monocrystalline silicon cells are constituted by a single crystal of silicon. â €
  • Polycrystalline or multicrystalline silicon cells are made up of a set of silicon crystals, which explains why their yield is somewhat lower than that of monocrystalline cells.
  • Amorphous silicon cells. They are less efficient than crystalline silicon cells, but also less expensive. This type of cell is, for example, the one used in applications such as calculators or small devices that do not require a large amount of energy.

Power Inverters

The inverter is an electronic device responsible for converting the direct current generated in alternating current.

The photovoltaic solar panel provides electricity in the form of direct current. This current can be converted into alternating current by the current inverter and injected into the electrical network or into the internal network.

The process, simplified, would be as follows: Energy is generated at low voltages (380-800 V) and in direct current. It is transformed by an inverter into alternating current. In power plants under 100 kW power is injected directly into the distribution network in low voltage (400 V in three-phase or 230 V in single-phase). And for powers over 100 kW a transformer is used to raise the energy at medium voltage (up to 36 kV) and it is injected into the transport networks for its later supply.

Solar trackers

The solar trackers are mechanisms that are orienting the position of the photovoltaic panels depending on the position of the Sun to increase its performance. Its use is quite common in the production of solar energy.

Solar trackers allow a considerable increase in solar production, around 30% for the former and an additional 6% for the latter, in places with high direct radiation.

There are solar trackers of various types:

  • Solar trackers on two axes: the surface of the photovoltaic panel always remains perpendicular to the Sun.
  • Solar trackers on a polar axis: the surface of the solar panel rotates on an axis oriented to the south and inclined at an angle equal to the latitude. The turn is adjusted so that the normal to the surface coincides at all times with the terrestrial meridian that contains the Sun.
  • Solar trackers on an azimuthal axis: the surface rotates on a vertical axis, the angle of the surface is constant and equal to the latitude. The turn is adjusted so that the normal to the surface coincides at all times with the local meridian that contains the Sun.
  • Solar trackers on a horizontal axis: the surface rotates on a horizontal axis and oriented in a north-south direction. The turn is adjusted so that the normal to the surface coincides at all times with the terrestrial meridian that contains the Sun.

Wiring

The wiring is the element that transports the electrical energy since its generation, for its later distribution and transport. Its sizing is determined by the most restrictive criterion between the maximum potential difference and the maximum admissible intensity.

Autonomous photovoltaic solars installations and connected to the grid

Taking into account these complementary elements, the types of basic photovoltaic installations are clearly differentiated:

In the following sections we will explain and comment on the different elements that make up a photovoltaic solar installation depending on whether they are autonomous or are connected to the network.

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Last review: May 18, 2018