Energy is essential for human life. Whether it is for basic survival needs like growing food or luxury items like yachts, energy makes the world go around. Humans rely on fossil fuels to keep society running. We dream of the day when we will be able to access the sun’s energy to directly power our homes and automobiles. This dream has been unfulfilled but with recent rapid advances in technology and rises in the price of fossil fuels, it seems that solar energy may soon become a practical reality.
The first steps toward the realization of this dream began in the laboratory of Edmund Becquerel in 1839. Becquerel was a French physicist who was very interested in light and its properties. He was also interested in the effects that light had on material things and in particular things that were phosphorescent and would glow after exposure to light. Becquerel noticed that some materials would develop a small electric current when exposed to solar energy. He placed silver chloride into an acidic solution. He then illuminated the solution while it was connected to platinum electrodes. A small current was generated between the electrodes. This has become known as the photovoltaic effect and Becquerel had invented the first photovoltaic device. The current was too small to have a practical use but it was clear that solar energy could in some fashion be converted directly to electrical energy.
What was happening in this device? How does solar power work? It would take a long time for the answer to this question to emerge. By the 1880’s many scientists were developing working photovoltaic cells. Albert Einstein’s research on the nature of light and energy yielded a theoretical understanding of the photovoltaic process. Scientists at Bell Labs in the 1950’s discovered the photovoltaic properties of silicon quite by accident. Today almost all solar cells use silicon to absorb the sun’s energy. Many great scientists contributed to the development of today’s solar cells.
So how does the photovoltaic effect work? When light hits a material with photovoltaic properties like silicon, the electrons in the substance absorb the energy and break from the atom to which they are attached. These electrons flow freely in the material. By placing two materials of different crystalline structure together, the electrons are encouraged to flow in one direction. This directional flow generates an electric current in the solar cell which can then be harnessed to provide power.
The time seems to be at hand for the adaptation of solar power on a massive scale. Governments have begun to provide rebates and other incentives for people to install solar systems in their homes. It is possible to generate enough electricity from solar cells on a rooftop to supply most of the power needs for that residence. What started as a small current in Edmund Becquerel’s lab is about to become a serious alternative to fossil fuels. We are on the advent of a new age of energy.
About the Author
Jennie is a blogger and advocate of solar power and eco-friendly products. She is excited to see the use of solar power in Perth continue to grow.