What are Solar Panels and How do They Work?

A solar photovoltaic array may consist of just a few PVC's or dozens, depending on the energy need for which the array has been produced.

Electricity is produced as photons from sunlight strike a layer of silicon and other elements, exciting electrons in the atoms of those elements. A flow of electrons is created, in turn allowing an electric current to form.

It is this current (direct current or DC) that can be used to operate electrical devices or can be stored as chemical potential energy in a battery or series of batteries. The direct current electricity can, when needed, be converted to alternating current (AC) for household or industry use when needed.

History of the Solar Panel

Solar panels have a long history of use, beginning with the space programs in the United States and other countries.

In 1954, Bell Labs developed the first silicon photovoltaic cell. This cell had an efficiency of 4%. Scientists at Bell Labs were later able to achieve 11% efficiency from the same type of PVC in later experiments. In 1958, the Vanguard I space satellite used a small array of PVC's to produce less than 1 watt of power for its radios.

Later that year, other satellites in the United States and Russia were successfully fitted with solar arrays. There were limited commercial or private uses for PVC's at this time due to the low power produced and cost of them at this time.

It was not until the 1970's and '80's that the use of solar energy panels became more common is the lives of average citizens. In 1979, a 3.5 kW system was installed on the Papago Indian Reservation in southern Arizona.

For 4 years, the system allowed the powering of a water pump and the electricity in 15 homes until grid power was made available to the reservation. The system is still in use today as a means of pumping water to the residents of the reservation.

You can learn more about the history of solar power in the 20th century, and also more recent developments in the history of solar energy from 1980's to the present time.

Present and Future Outlook for the Residential Solar Panel

Things have advanced in photovoltaic technology over the past few decades. Solar cells are very commonly seen in everyday devices such as calculators and traffic lights. It's also common to see them in new public buildings and housing construction.

Part of this revitalization in the solar cell industry is because of the growing efficiency of current PVC's, which at the present time is around 20-25%. This may seem to still be a bit inefficient, but when compared to the earliest cell's efficiency of 4%, PVC technology has grown tremendously.

As you can see from the chart below, the production of Photovoltaic Arrays in the world has continued to increase since 1980.

It is also noteworthy to compare the efficiency of current PVC's to the average automobile engine, with an efficiency averaging only 30%. New technologies are being developed every day, and this comparison makes it easy to see that the use of PVC's could bring about a revolution in energy collection and usage over the next several decades.

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