Panels photovoltaic solar energy

Photovoltaic solar energy

Photovoltaic solar energy

Photovoltaic solar energy consists of the direct transformation of solar radiation into electrical energy. This type of energy is often referred to directly as photovoltaics.

This transformation in electrical energy is achieved by taking advantage of the properties of semiconductor materials through photovoltaic cells. The base material for the manufacture of photovoltaic panels is usually silicon. When sunlight (photons) hits one of the faces of the solar cell, it generates an electric current. This generated electricity can be used as an energy source.

The manufacture of photovoltaic cells is a costly process, both economically and in time. The silica with which photovoltaic cells are manufactured is a very abundant material on Earth. However, the processing of silicon is laborious and complicated. By means of very complicated processes, silicon ingots are made. Subsequently, these wafers ( photovoltaic cells) will be cut from these silicon ingots.

Another source for obtaining silicon is the recycling of the electronics industry.

At present, other higher performance materials are being prepared.

It is important that all the cells that make up a solar photovoltaic panel have the same characteristics. After the manufacture of the photovoltaic cells, it is necessary to follow a process of classification and selection.

Efficiency of photovoltaic solar energy

Depending on the construction, the photovoltaic modules can produce electricity from a specific range of light frequencies, but in general it can not cover the entire solar range (in particular, ultraviolet, infrared and low or diffuse light). Therefore, much of the energy of the incident sunlight is not used by the solar panels, which could give much higher efficiencies if it is illuminated with monochromatic light.

Photovoltaic panels - photovoltaic solar energyTherefore, another design concept is to divide the light into different wavelengths and direct the beams in different cells tuned to these ranges. This has been projected to be able to raise efficiency by 50%. Scientists from Spectrolab, a subsidiary of Boeing, reported the development of multi-union solar cells with an efficiency of more than 40%, a new world record for photovoltaic solar cells. Spectrolab scientists also predict that concentrating solar cells could reach efficiencies of more than 45% or even 50% in the future, with theoretical efficiencies of around 58% in cells with more than three junctions.

Currently, the best rate of conversion of sunlight into photovoltaic solar energy in new commercial products achieves an efficiency of the solar module of around 21.5%.

Applications of photovoltaic solar energy

The main application of a photovoltaic solar energy installation is the production of electrical energy from solar radiation.

Energy production can be large-scale for general or small-scale consumption for consumption in small dwellings, mountain shelters or isolated sites.

Utilization of photovoltaic solar energy for public lightingMainly differentiate two types of photovoltaic installations:

  • Photovoltaic installations for grid connection, where the energy produced is used entirely for sale to the distribution network.
  • Photovoltaic installations isolated from the grid, which are used for self-consumption, be it an isolated dwelling, a telecommunication relay station, water pumping for irrigation, etc.

Within the applications of photovoltaic solar energy not connected to the grid we find in many areas of daily life. Photovoltaic solar energy is used in small devices such as calculators, as for street lighting in certain areas, to power electric motors and even cars and airplanes have been developed that work exclusively by taking advantage of solar radiation as an energy source.

Within the photovoltaic installations connected to the network there are solar photovoltaic power plants. A photovoltaic power plant, also a solar park or photovoltaic power statio, is a large power generation plant, designed for the sale of its production to the electricity grid. It is also known as a solar farm, especially if it is located in agricultural areas.

History of photovoltaic solar energy

The photovoltaic solar energy generated with the photovoltaic effect was recognized for the first time in 1839 by the French physicist Becquerel. However, it was not until 1883 that the first solar cell was built by Charles Fritts with an efficiency of 1%. During the first half of the 20th century there were several improvements to increase its efficiency.

In 1946, Russel Ohl patented the modern union between semiconductor materials that is currently used. But the most important technological advance came in 1954 when Bell Laboratories, experimenting with semiconductors, developed the first silicon photovoltaic cell, with a yield of 4.5%.

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References

  1. Roper, L. David. World Photovoltaic Energy
  2. REN21 (2009). Renewables Global Status Report: 2009 Update
  3. Swanson, R. M. (2009). Photovoltaics Power Up
  4. «Photovoltaic Effect»  Mrsolar.com
  5. «The photovoltaic effect»  Encyclobeamia.solarbotics.net.
  6. «La fotovoltaica ya se codea en costes con la nuclear». El periódico de la energía. 

Last review: February 25, 2019