Solar panels - EN

Solar panels

Solar panels on the roof

Solar panels are panels that convert sunlight into electricity. For this purpose, the panels are provided with solar cells that collect the light from the sun. The solar cells are also called Photo-voltaics abbreviated to PV cell.

To make clear distinction a solar panel that generates electricity is something other than solar panels or solar water heater (solar thermal collector) using solar energy as a heat source.

Solar energy is energy from the sun in the form of heat and light, both the heat and light of the sun can be converted into reusable renewable energy. In the form of this light is converted into electricity, heat is generally used in the collected heat to warmup a liquid such as water.

With solar energy is currently intended; the energy which is generated directly from solar radiation. This happens in two ways:

  • The most common application is by means of solar panels with photovoltaic cells (also known as PV-cells). Which convert light directly into electricity: solar power.
  • Another way to make use of solar thermal energy is sunlight where sunlight is converted to heat. This is done by solar water heaters (or solar thermal collector).


The history of the development of the solar cells will find mostly originated in space traveling technology, because for long space missions (such as satellites or space station) was impossible to carry enough fuel or energy storage (batteries) there had developed a method be in order to generate energy. This was the beginning of the 50s and 60s still quite expensive due to the expensive materials, as the technology has advanced it became more affordable. This technological development became cheaper by the use of, for example, silicon for solar cells. At one time, the acquisition costs for consumers and efficiency that can deliver at a point that was reached an acceptable payback border. This makes it possible for consumers was to buy their own panels and thereby generate sufficient savings to regular energy supplies which the investment would pay back in a few years. However, this is more dependent on factors such as the energy suppliers prices, other renewables and instance storage capabilities.

  • 1839, the French physicist Alexandre-Edmond Becquerel for the first time  observes the 'photovoltaic effect'.
  • 1883, the American scientist Charles Fritts utilized as a first this phenomenon for the construction of a light cell based on selenium. This seleniumcel could convert only 1 percent of light into electricity and was mainly used in photography as an exposure meter.
  • 1887 German physicist Heinrich Hertz discovered the principle of the photoelectric effect in which light is converted directly into electricity.
  • 1890, the Russian physicist Aleksandr Stoletov built the first solar cell based on the principle of the photoelectric effect.
  • 1941 was the modern semiconductor solar cells based on silicon patented by the American Russell Ohl, then working at Bell Labs. In May 1939 by chance he discovered that a spontaneous electric current was generated in a silicon crystal when it shone with a desk lamp.
  • Continuing on the work of Ohl at Bell Labs, Gerald Pearson, Calvin Fuller and Daryl Chapin developed a more efficient solar cell in 1954. By doping silicon with arsenic, they built a solar cell that achieved a yield of 4½ to 6 percent.
  • 1958, the US satellite Vanguard 1 was the first artificial satellite that sent out radio signals from space powered by a solar cell of 1 watt. Vanguard 1 was made of aluminum, and had a diameter of 16.5 cm weighed only 1.47 kg and was fitted with six square solar cells of 5 x 5 cm.
  • Only after the oil crisis in the 1980s, solar cells were manufactured based on gallium arsenide (GaAs), designed with an efficiency of over 20 percent.


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