Solar energy and home solar panels have a surprisingly long history. Humans have used solar energy in creative, beneficial, and even civilization-changing ways for more than 2,000 years.
Our quick trip through the history of solar power, from ancient civilizations to major milestones reached in 2024, points to exciting new solar developments in years to come.
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The Early Days of Solar Energy
Humans began using solar energy to start fires as early as the 7th century BCE. By holding clear pieces of glass over dry wood, they could focus the sunlight on a single point and kindle a flame.
A few centuries later, Romans and Greeks developed mirror technology that could harness solar power to light torches for ceremonies. If you've ever had light from the sun hit you after bouncing off a mirror, you know this can be an effective method of focusing that energy. These "burning mirrors" gained popularity, and the Chinese began using them around 20 CE.
Beyond its ability to kindle flame, people have used the sun to warm their houses for hundreds of years. Across centuries and cultures, we find sunrooms designed with massive windows to direct sunlight into a specific area. Some Roman bathhouses were built with windows facing the south to create such sunrooms. Over in the American Southwest, the Anasazi built houses on cliffs facing south to help warm their homes during the winter.
Solar ovens, like you may have created in middle school science class, were first developed in the late 1700s as a way to cook food during long voyages.
In the 1800s, people created solar-powered steamboats to aid water travel. The December 1, 1870 issue of The Technologist reports on Captain John Ericsson’s attempts to use solar rays to help power steamboats.
The Science Behind Solar Power
These early methods of harnessing the sun’s energy likely fostered the technologies we see today, including the creation and continued development of solar panels.
To understand how solar panels work today, it helps to understand the photoelectric effect and the photovoltaic effect. These two effects are the foundation of modern solar power.
Photoelectric effect
The photoelectric effect occurs when a material or substance is exposed to electromagnetic radiation such as light, causing electrons in the material to be emitted as free particles.
When light hits a piece of metal, the electrons in the metal will absorb the energy and become excited, increasing its kinetic energy. If the kinetic energy of the electron is great enough to overcome the binding energy of the atom, the electron will be released as a free particle.
Photovoltaic effect
The photovoltaic (PV) effect, like the photoelectric effect, occurs when a material or substance is exposed to light, causing electrons in the material to become excited. However, the photovoltaic effect results in an electric current. This means the electrons are not ejected but instead stay in the materials.
You can observe this effect in semiconductors or any materials with a conductivity level between a conductor and an insulator. When light hits a semiconductor, the electrons cannot leave the material like they do in the photoelectric effect.
Instead, when the electrons absorb energy, they enter an excited state. At this point, the electrons are freed so they can cross the barrier between two different substances. The end result is the creation of an electric current.
The Development of Solar Electricity
The discovery of the photoelectric and photovoltaic effects led to significant advances in the understanding and use of solar power. Multiple scientists contributed research that ultimately evolved into what we think of as the modern-day solar panel.
- 1839 - French scientist Alexandre-Edmond Becquerel created a photovoltaic cell, inspiring future developments in photovoltaics.
- 1873 - Willoughby Smith discovered the photovoltaic effect in selenium.
- 1883 - Charles Fritts developed a solar cell using selenium coated with gold.
- 1883 - John Ericsson created a “sun motor” to run a steam boiler using parabolic trough construction, a set of concave mirrors that concentrate solar rays on a receiver tube to convert sunlight into clean energy.
- 1884 - Charles Fritts installed solar panels on a New York City rooftop.
- 1888 - Wilhelm Hallwachs described the physics of photovoltaic cells. This became known as the Hallwachs Effect, which occurs when a negatively charged body in a vacuum is released after being exposed to ultraviolet radiation.
- 1905 - Albert Einstein explained how light can create an electric current by knocking electrons out of the atoms in certain metals.
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Invention of the Modern Solar Panel
Our look at solar energy history continues into the 20th and 21st centuries with ongoing advancements in solar panels. With multiple theories that proved the potential of solar power, people advanced solar technology in the following year..
- 1912 - The Sun Power Company used parabolic trough construction to build the world's first solar thermal power plant.
- 1916 - Jan Czochralski invented a method of creating single crystals of metal. This served as the basis for the semiconductor wafers that are still used today in electronics like solar cells.
- 1941 - Bell Laboratories engineer Russel Ohl filed a patent for the first monocrystalline silicon solar cell.
- 1947 - Passive solar houses grew in popularity because of an energy shortage after World War II, a trend that reimagined the “sunrooms” of antiquity.
- 1951- The first solar cells made from germanium were constructed.
- 1954 - Bell Labs made the world’s first solar panel from silicon, though it was only 4% efficient.
- 1955 - 1960 - The first solar-powered telephone call was made; the first solar-powered radio was sold by General Electric; and Vanguard I became the first spacecraft powered by solar panels.
- 1960 - Hoffman Electronics improved photovoltaics from 8% to 14%efficiency.
- 1962 - 3,600 cells from Bell Labs powered Telstar, the first solar-powered communications satellite.
- 1967 - The USSR launched Soyuz 1, the first solar-powered spacecraft to carry humans.
- 1972 - The Synchronar 2100 solar-powered watch entered the market.
- 1970s - The United States government passed several pieces of legislation and created agencies to increase and regulate solar energy usage.
- 1981 - The Solar Challenger became the world's first solar aircraft capable of flying long distances.
- 1982 - The first large-scale solar farm was built in California.
- 1985 - Lithium-ion batteries were developed.
- 1985 - The Centre for Photovoltaic Engineering at the University of New South Wales in Australia developed the first silicon cells to reach 20% efficiency.
- 1991 - Lithium-ion batteries entered commercial production.
- 1999 - NREL and SpectroLab Inc. created a solar cell with 32% efficiency.
- 2005 - The Federal Investment Tax Credit (ITC) was originally created by the Energy Policy Act of 2005
- 2008 - NREL achieved a world record when they reached 40.8% solar cell efficiency.
- 2015 - Tesla released the Powerwall battery pack, which allows rooftop solar owners to use solar battery storage to store electricity.
- 2015 - Google released Project Sunroof to help homeowners decide if rooftop home solar was feasible for their house.
- 2020 - Experts calculated it’s less expensive to build a new solar plant than to continue operating an existing coal plant.
- 2020 - California required all newly built homes to include solar panels.
- 2022 - The Inflation Reduction Act of 2022 extended tax credits for solar panels and other clean energy projects to at least 2034.
- 2024 - The US reached five million solar power installations in May according to the Solar Energy Industries Association. Residential solar systems are about 97% of the installations. While it took about 50 years to get to five million, SEIA projects the US will reach 10 million installations in about six years, in 2030.
- 2024 - Solar and wind energy combined will exceed energy used from coal for a calendar year in the US for the first time according to the US Energy Information Administration.
Notable Solar Power Firsts in Modern History
While solar power technology has been around for thousands of years, some of the most significant developments in the history of solar panels have occurred in recent years. Here are a few notable inventions of solar energy:
The Sunmobile
William G. Cobb invented the first solar-powered vehicle in 1955 while working for General Motors. The 15-inch-long vehicle was called the “Sunmobile” and had 12 photovoltaic cells made of selenium.
Adventures in the air
One of the most surprising solar energy history facts is solar panels were put in outer space as early as 1958 when the Vanguard I satellite used a tiny one-watt panel to power its radios. Solar panels are still an important part of space technology today.
The Solar Challenger was the first solar-powered plane capable of flying long distances. In 1981 it made a 163-mile flight over the English Channel from France to the UK.
In 1998, a remote-controlled solar airplane dubbed Pathfinder Plus set an altitude record for propeller-driven aircraft when it reached 80,000 feet. That record for non-rocket aircraft was broken in 2001 by NASA when it hit 96,000 feet with its solar-electric Helios project. In 2016, the Solar Impulse 2, flown by Bertrand Piccard, completed the first flight around the world by a piloted fixed-wing aircraft using only solar power.
Domestic developments
In 1973, the first completely solar-powered building, Solar One, was built in Delaware. The building operated on a hybrid supply of solar PV panels and solar thermal power. It also included the first example of building-integrated photovoltaics , meaning it had solar integrated into the rooftop itself.
Several government buildings have been partially or fully run by renewable resources. For example, President Jimmy Carter had a solar array installed on the White House in 1979, but President Ronald Reagan had them removed a few years later. During his first term in 2010, President Barack Obama had a solar panel system and a solar heater installed at the White House.
In 2016, Las Vegas became the largest city government in America to be run entirely on renewable energy. Part of this energy comes from solar panel trees in front of the city hall.
In the last decade of the solar power history timeline, several US cities have made the switch to generating electricity with solar and being powered by 100% renewable energy:
- Aspen, CO
- Greensburg, KS
- Burlington, VT
- Kodiak Island, AK
- Rock Port, MO
- Eugene, OR
- Georgetown, TX
Sierra Club reports that over 180 U.S. cities have committed to powering their communities with 100% renewable energy by 2035.
Become a Part of Solar’s Future
Everything from using a magnifying glass to start a fire to using solar panels to power your home can be considered solar energy. Thus, exploring the history of solar energy will lead you on a fascinating chase across thousands of years of human ingenuity.
If you’re ready to learn more about installing the right solar power system on your home, contact Palmetto today. You can even get started by using our free Estimate Your Savings Tool to see how you could lower your electricity bill.
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Frequently Asked Questions
When did we discover solar energy?
Humans discovered solar energy as early as the 7th century BCE, using solar energy and glass to make fire.
Who invented the solar panel?
New Yorker Charles Fritts used solar cells made of selenium coated in gold and installed the first solar panels on a building, on a roof, in New York City in 1884. The first modern silicon solar panel was developed by Bell Labs in the 1950s.
Andrew GiermakWriter and EditorAndrew joined Palmetto in Charlotte in August 2024. He’s been a writer in journalism, then in business, going back to almost the 20th century. He’s lived in Indiana, Virginia, Pennsylvania, Virginia again, and now North Carolina for the last 12 years. He likes golf. Is he good at it? Not so much.
