Nathaniel Fernandes ’20

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The discovery and development of photovoltaic cells is among the most thrilling inventions of our time. If harnessed effectively, solar energy can liberate us from fossil fuels, power the earth for off only a tiny landmass [1], and save vital resources like lumber or natural gas for future generations. Of all renewable energy forms, solar energy is the most promising since the technology is already commercially viable, widely used, and fairly efficient too (at about 20% efficiency).

But how did this outstanding technology develop? A combination of technological inventions and societal influences induced the development of the solar panel to turn this bright idea into a hot product.

Humans have used solar energy for thousands of years, including as sun roofs by the Aztec, Inca, Maya, Egyptians, and Romans and as deadly “fire death rays” by the Greeks (although the veracity of this is disputed). However, the modern-day ability to harness the sun’s energy in an electrical capacity is made possible by three landmark technological advancements including the discovery of photovoltaic effect, advancement of semiconductor technology, and the transistor.

In 1839, Edmond Becquerel discovered the photovoltaic effect after submerging two electrodes in a conductive solution and exposing it to light. The result was an electric current! Instead of using a liquid solution, modern solar panels harness a p-n junction to move electrons in a conductive circuit, a technique discovered by Russell Ohl in 1941. With a p-n junction, two semiconductors are doped positively and negatively which creates a band gap that electrons travel through once they are knocked off a metal atom (similar to how the electrons traveled through the aqueous solution in Becquerel’s model) [2]. Finally, the solar panel (and all other electrical devices) would not be possible without the transistor which enabled panels to become more compact, efficient, and easily built. Facing increased demand for solar energy, various research groups made a series of improvements to boost solar panel efficiency, which made solar panels an increasingly practical alternative to traditional forms of energy.

Although solar panels seem like solely a technological invention, they wouldn’t exist without various social factors that helped fund research and popularize this budding technology. Once solar panels became viable, the news media, other organizations, and influential people helped popularize the technology. For example, in 1954 after Bell Labs produced a 6% efficient silicon solar cell, the New York Times speculated that this technology would unlock the “limitless energy of the sun.” Additionally, the UN has held a conference on solar energy, “Solar Energy in the Developing World,” and President Bush and Pope Benedict XVI have added solar panels to their respective residences as a model for others to follow. One other major social pressure that prompted vast government funding into solar energy research was the Arab Oil Embargo in 1973. After being stiff-armed by OPEC, Congress created the Solar Energy Research Institute (later renamed the National Renewable Energy Laboratory) to fund this research in 1974. Social factors like these helped fuel research, decrease solar panels’ cost of production, and increase the nation-wide supply and demand for solar energy. 

As more social factors pressure more research and technological discoveries, photovoltaic cell technology will become more cost-effective and holds incredible promise to become the next dominant form of energy production.

Links to more information:

[1] How much land would have to be covered by solar panels to power the US?: https://www.freeingenergy.com/how-much-solar-would-it-take-to-power-the-u-s/

[2] Understanding the p-n junction: https://www.khanacademy.org/science/in-in-class-12th-physics-india/in-in-semiconductors/in-in-the-pn-junction/v/the-pn-junction-class-12-india-physics-khan-academy

Extra Information:

https://energyinformative.org/the-history-of-solar-energy-timeline/