The History of Solar Energy

With rising energy costs, climate change, and an increasingly taxed electrical grid, many people are turning to alternative sources of electricity to power their lives. This is especially true here in Arizona, where abundant sunshine offers residents a unique opportunity to tap into a clean and renewable energy resource year-round. But solar is far from new - it has been around for centuries! In recent years, however, as its popularity has grown, competition and advancements in manufacturing techniques have made solar power more capable and accessible than ever before.

Let’s take a closer look at the history of solar power to learn more about how solar energy started and how far we have come.

When was solar energy first used?

Solar energy has a long history that - believe it or not - dates back to ancient civilizations. The concept of harnessing solar power goes as far back as the 7th century BC, when humans used magnifying glass materials to light fires. Later, in the 3rd century BC, ancient Greeks and Romans used mirrors to light torches for religious ceremonies. Chinese civilizations were known to use these same tools, called ‘burning mirrors’, in 20 AD. 

Other early uses of solar energy include adding ‘sunrooms’ to buildings. These involve using large windows to direct sunlight into a particular area of a building, providing heat and light. Many ancient Roman bathhouses used sunrooms, and around 1,200 AD the Anasazi people - ancestors of the Pueblo Native Americans - moved to south-facing dwellings during the winter to harness the sun’s warmth. In the late 1700s and early 1800s, researchers discovered how to use sunlight to power ovens during long sea voyages and even produced solar-powered steamboats. 

When it comes to more modern applications of solar energy, though, things started to develop around the 19th century. Let’s take a closer look at the modern-day development of solar panels.

When were solar panels invented?

The invention of solar panels was an iterative process that involved numerous contributions from different scientists across the world. Who exactly invented solar panels, and when, is up for debate, and you might get a different answer depending on who you ask.

Many people credit the invention of solar technology to the French physicist, Edmond Becquerel. In 1839, Becquerel was the first person to discover the photovoltaic effect, the phenomenon where sunlight is converted into electricity. This discovery laid the groundwork for the development of solar power as we know it today. 

In the late 19th and early 20th centuries, various scientists and inventors experimented with different materials and methods to harness solar energy. In 1873, for example, Willoughby Smith discovered that the element selenium had photoconductive properties. A few years later, in 1876, William Grylls Adams and Richard Evans Day found that selenium created electricity when exposed to sunlight. Less than a decade later, Charles Fritts made the first solar cells out of selenium wafers. Because of this discovery, many people credit Fritts as being the inventor of solar cells, but his discovery wasn’t efficient enough for practical use - which is why the solar panel of today uses silicone instead of selenium. 

In 1954, researchers Daryl Chapin, Calvin Fuller, and Gerald Pearson invented the first silicon solar cell which marked the beginning of the modern solar industry. This solar cell was the first practical photovoltaic (PV) device, capable of converting sunlight into electricity efficiency enough to power an electric device for several hours of a day. 

While these early cells were still lacking in efficiency compared to today’s technology, they paved the way for the development of more efficient solar panels. Today’s widespread use of solar energy wouldn’t exist without the breakthrough at Bells Labs in 1954.

The history of solar power: a timeline

Let’s travel throughout history and take a look at the small steps and milestone events that led to the development of solar power as we know it today. 

7th Century BC: Humans first discovered they could harness the sun’s rays to start fires using magnifying glasses that concentrated sunlight. 

3rd Century BC: Ancient Greeks and Romans used mirrors to reflect sunlight and light torches for religious ceremonies. 

2nd Century BC: The Greek scientist, Archimedes, allegedly used bronze shields to focus sunlight on invading Roman ships, setting them ablaze. (No proof of this event exists but it was successfully recreated in 1973).

20 AD: The ancient Chinese used burning mirrors to light torches for religious ceremonies.

1st - 4th Century AD: Roman bathhouses used large south-facing windows to harness the sun's warmth. 

1200 AD: The Anasazi people in North America lived in south-facing dwellings to capture the sun’s heat and keep warm throughout winter. 

1767: Swiss scientist, Horace de Saussure, built the world's first working solar oven. This was later used by Sir John Herschel to cook food during an expedition in South Africa.

1839: French physicist, Edmond Becquerel, discovered the photovoltaic effect - the process in which a material can convert light into electricity - while experimenting with a cell made of metal electrodes placed in an electricity-conducting solution. 

1860s: August Mouchet, a French mathematician, put forth the notion of solar-powered steam engines. In the next 20 years, he and his assistant, Abel Pifre, would build the world’s first solar-powered engines.

1873: English electrical engineer, Willoughby Smith, discovered that selenium could conduct electricity when exposed to light. 

1876: William Grylls Adams and Richard Evans Day used selenium to produce electricity from light, demonstrating that solid materials could convert sunlight into electricity without any heat or moving parts. 

1883: American inventor, Charles Fritts, created the first working selenium solar cell. This solar cell was inefficient compared to today’s standards, capable of converting less than 1% of sunlight into electricity. 

1887: The world’s first commercial solar water heater was patented by inventor Clarence Kemp.

1905: Albert Einstein published a paper on the photoelectric effect, explaining how light could release electrons from a material. This discovery earned him the Nobel Prize in Physics in 1921.

1918: Polish scientist, Jan Czochralski, developed a method to grow single crystal silicon, an essential component in modern solar cells.

1941: Russel Ohl invented the first silicon solar cell, which would become the foundation of modern solar technology. 

1947: Scarce energy during the WWII period made passive solar buildings popular in the United States, leading to the publication of 'Your Solar House', a book that profiled the best solar architects in the country.

1954: The birth of modern photovoltaics was marked by Daryl Chapin, Calvin Fuller, and Gerald Pearson of Bell Labs producing the first practical silicon solar cell, which had 4% efficiency. They presented their findings by powering a small toy windmill and radio by solar energy. The New York Times heralded this discovery as "the beginning of a new era, leading eventually to the realization of harnessing the almost limitless energy of the sun for the uses of civilization."

1955: The first commercial licenses for silicon PV technologies were sold by Western Electric. 

Mid-1950s: The world’s first solar heated office building was designed by Frank Bridgers, using solar water heating. This solar system is still in use today. 

1956: The first solar cells were made commercially available to the public. While the initial cost, $300 for a 1-watt solar cell, was out of reach for most, it was enough to begin a new wave of experimentation and discovery and a new dawn for the history of solar power.

1958: Photovoltaic cells with 9% efficiency were developed by Hoffman Electronics.

1958: The Vanguard 1 satellite used a small solar array to power its radios, demonstrating the potential of solar energy in space applications. That same year, Explorer III, Vanguard III, and Sputnik-3 were all launched with PV-powered systems on board and solar power remains the most widespread energy source for space applications today. 

1959: The first commercially viable, 10% efficiency PV cells are achieved by Hoffman Electronics. 

1960: Just one year later, Hoffman Electronics achieves 14% efficient PV cells. 

1963: The world’s largest solar array, 242-watts, is installed on a lighthouse in Japan. 

1864: The first Nimbus aircraft is launched by NASA, powered by a 470-watt solar array. 

1970s: Photochemicist, Dr. Elliot Berman, along with oil company Exxon Corporation, designed a solar cell that greatly reduced the price of solar energy from $100 a watt to $20 per watt. With solar power becoming more affordable, solar cells were used to generate electricity that powered navigation warning lights and horns on railroad crossings, lighthouses, and offshore gas and oil rigs. 

1972: A solar-powered educational television is installed at a village school in Niger. 

1972: The world's first dedicated PV research and development laboratory is established at the University of Delaware. 

1973: Just a year later, one of the earliest PV-powered residences was built by the University of Delaware. 

1976: NASA’s Lewis Research Centre began installing PV-powered systems on every continent except Australia to power medical clinics, telecommunications, water pumps, grain mills, and classroom TVs. The project was completed in 1995. 

1977: The Solar Energy Research Institute is established by the US Department of Energy, now known as the National Renewable Energy Laboratory. 

1978: The world's first village PV system is installed on the Papago Indian Reservation in Arizona, providing electricity and water pumping for 15 homes that weren’t connected to grid electricity. 

1981: The world's first solar-powered aircraft was built by Paul MacCready and flown across the English Channel. 

1982: California becomes home to the first PV megawatt-scale power station. 

1982: The world's first solar-powered car is driven by Australian, Hans Tholstrup, between Sydney and Perth. The trip takes 20 days, significantly faster than the first gasoline-powered car, which took 30 days. 

1985: The University of South Wales develops 20% efficiency silicon solar cells under 1-sun conditions. 

1992: 15.9% efficiency thin-film PV cells are developed by the University of South Florida. 

1993: The first grid-supported solar system was installed in Kerman, California.

1994: The first solar cell to exceed 30% efficiency is developed by the National Renewable Energy Laboratory. 

2000: Astronauts at the International Space Station installed solar panels that went on to be the largest solar array in space.

2000: A new inverter developed by Sandia National Laboratories increases safety during power outages.  

2001: Residential solar power systems can be purchased at Home Depot for the first time. 

2004: California Governor, Arnold Schwarzenegger, proposed the Solar Roofs Initiative, incentivizing the state of California to achieve 1,000,000 solar roofs by 2017. This brought national attention to the initiatives and incentive programs that could be available across the U.S. 

2006: The Solar Investment Tax Credit (ITC) was introduced to support the adoption of solar energy in the United States. The ITC provided a financial incentive for both residential and commercial solar systems with a tax credit of 30% of the cost of installing solar panels. This credit was instrumental in the growth of the solar energy industry and made solar power more affordable and accessible. 

2007: A new milestone in solar technology is achieved when the University of Delaware developed a 42.8% efficiency solar cell. This breakthrough marked an important turning point where fewer panels, working at a greater efficiency, could drastically shift the return on investment in favor of solar energy

2010s: Solar power became more mainstream, with large-scale solar farms and residential installations becoming common. New materials were developed that promised higher efficiency at a lower cost, making solar more accessible. 

2020s: Solar energy became used in everyday products, such as portable chargers and solar windows. Advances in technology, such as lithium-ion batteries, provided more reliable energy storage solutions. 

Solar energy: the future

Here's how we anticipate the future of solar technology to look like... 

• Net-zero energy buildings: All buildings will be constructed with energy-efficiency in mind, using renewable energy technologies for net-zero energy building. 

• Innovation in solar materials: PV research and development will pave the way for innovative approaches to solar materials and products. Imagine a future where your clothes and vehicles can produce clean, safe, and renewable energy. 
• More efficient energy storage solutions: Batteries power so much in our modern world that battery technology is poised to advance exponentially in the coming decades. Batteries take all the benefits of solar and make them available even at night or on cloudy days.  

• Large-scale energy solutions: With continued research and development, concentrating solar power (CSP) can become as cost-effective as traditional power sources. Theoretically, a 100x100 mile solar power plant in the Southwest U.S. could generate enough power to meet all of the country's electricity needs, providing large-scale, secure, and eco-friendly electricity. 

Be a part of solar history

The sun’s energy is limitless and plentiful - what better way to power our everyday needs than by harnessing this valuable resource? Today, solar panels are more efficient and cost-effective than ever. If you’d like to use this clean and affordable energy source to power your home or business, the team at Sun Valley Solar Solutions is ready to help. Get in touch with us for a free, no-obligation consultation to see how solar energy can work for you.