Although solar has found its place in today’s clean energy market, there’s a long history to the photovoltaic technology that brought the idea of solar to life. With the dramatic drop in solar prices over the past 15 years, it’s easy to forget just how revolutionary going solar was a few decades ago. Let’s take a look back at solar PV’s roots and the history of both solar and silicon solar technologies.
When was solar energy first used?
It is thought that humans first harnessed solar energy in the 7th century BC when they used it to light fires using magnifying glass. In the 3rd century BC, the Greeks and Romans used mirrors to light torches during religious ceremonies. The use of mirrors became a common tool referred to as “burning mirrors” and was documented by Chinese civilization in the 6th century AD.
The concept of “sunrooms” in buildings was another early application of solar energy. Sunrooms were large windows that focused sunlight into a concentrated area. Many of the most famous Roman bathhouses were sunrooms. In the 12th century, the Anasazi, the ancestors of the modern-day Pueblo, built south-facing dwellings on cliffs to take advantage of the sun’s warmth during the cold winter months. In the 17th and 18th centuries, explorers and scientists were successful in using solar energy to power ovens and steamboats.
Ultimately, it’s clear that even thousands of years before the era of solar panels, the concept of manipulating the power of the sun was a common practice.
When were solar panels invented?
The history of solar panel technology is an iterative one, with many different scientists contributing to its development. As a result, there is some controversy over when solar cells were first invented and who should be held responsible.
Some scientists attribute the invention of solar cells to the French scientist Edmond Bequerel. Becquerel discovered that light could be used to increase electricity generation by placing two metal electrodes into a conducting solution, a phenomenon known as the “Photovoltaic effect.” This was a major influence on later PV developments using selenium, which was discovered by Willoughby Smith in 1873.
Willoughby Smith’s discovery of selenium’s photoconductive potential led to the 1876 discovery of electricity generated by selenium by William Greylls Adams and Richard Evans Day.
However, it wasn’t until a few years later – in 1883 – that Charles Fritts produced the world’s first solar cells using selenium-based wafers – that some historians attribute the invention to Fritts.
Many argue that this event marks the true invention of PV technology because it was the first instance of solar technology that could actually power an electric device for several hours of a day. The first ever silicon solar cell could convert sunlight at four percent efficiency, less than a quarter of what modern cells are capable of.
Major events in the history of solar energy
Solar panels in outer space
In fact, some of the first applications of solar technology have been in space, with solar power powering satellites. For example, in 1958, Vanguard I used a one- watt panel to power the satellite’s radios. In the same year, Vanguard II was launched, Explorer III followed in 1961, and in 1962, the first solar-powered spacecraft (Nimbus) was launched by NASA. In 1965, the world’s first orbiting observatory (Orbiting) was launched using a one-kW array. And in 1966, a solar-powered satellite (Sputnik-3) was launched, powered entirely by a solar array of 470 watts.
First solar residence
The University of Delaware’s first solar building was built in 1973, and was called “Solar One.” The system relied on a combination of solar thermal power and solar photovoltaic (PV) power. This was the first time a solar array was built – the array did not use solar panels, but instead incorporated solar into the rooftop structure, similar to Tesla’s new roof product design.
Achievements in solar conversion efficiency
Between 1957 and 1960 the efficiency of photovoltaic (PV) cells was greatly improved by the company Hoffman Electronics, which improved the previous record of 8% efficiency to 14%. Another notable achievement was achieved by the University of NSW in 1985 when 20% efficiency was achieved for silicon cells. Another notable achievement was made in 1999 by the National Energy Energy Laboratory (NEL) in collaboration with the company SpectroLab Inc., which produced a solar cell with an efficiency of 33.3%. In 2016, researchers at the University of NSW again set a new record of 34.5%.
Solar-powered airplanes
Paul MacCready created Solar Challenger in 1981, the world’s first solar powered aircraft to fly over the English Channel, from France to Great Britain. In 1998 the remote controlled solar airplane “Pathfinder” achieved an altitude record of 80,000 ft. NASA broke this record in 2001 with their non rocket aircraft reaching 96,000 ft. In 2016 the solar powered aircraft “Solar Impulse 2” made history as the first zero emissions flight in the world. This is the largest and strongest solar powered aircraft in the world today.
Solar-powered presidencies
Solar panels were installed in 1979 by President Jimmy Carter during his first term in office. The solar panels were removed by President Ronald Reagan in 1981. Solar panels were installed again during President Barack Obama’s first term in office in 2010. The solar water heater was also installed during his first term.
Cost of solar over time
The cost of solar panels has decreased significantly over the last few decades. This has led to an increase in consumer demand, resulting in more than one million installations in the U.S. as of the beginning of 2016.
In 1956, solar panels were priced at around $300 per watt, and by 1975, that number had dropped to a little over $100 per watt. Today, solar panels can cost as little $0.50 per watt.
Solar panel prices have decreased by at least 10% every year since 1980. The decreasing cost of solar is one of the main reasons for its increasing popularity and the legitimacy of photovoltaic (PV) technology in today’s world.
