The history of solar energy stretches back nearly 3,000 years, far longer than most people imagine.
Long before the first solar panel appeared on a rooftop, humans were concentrating sunlight to light torches, heat homes, and even (according to legend) set enemy ships on fire.
As an ANCE-certified solar technician who has designed and installed photovoltaic systems here in Mexico, I find that understanding how we got here makes you appreciate just how remarkable today’s technology really is.
A solar panel that cost over $100 per watt in the 1970s now costs less than $0.30 per watt. That didn’t happen overnight.
It happened through two centuries of scientific breakthroughs, geopolitical shocks, and relentless engineering.
In this guide, I’ll walk you through the complete history of solar energy, era by era, highlighting the breakthrough that defined each period.
History of Solar Energy at a Glance
| Era | Period | Defining Breakthrough |
|---|---|---|
| Ancient Era | 700 BC – 1500 AD | Burning mirrors and passive solar architecture |
| Early Scientific Era | 1767 – 1839 | Becquerel discovers the photovoltaic effect (1839) |
| Selenium Era | 1873 – 1904 | Fritts builds the first working solar cell (1883) |
| Theoretical Era | 1905 – 1953 | Einstein explains the photoelectric effect (1905) |
| Silicon Era | 1954 – 1972 | Bell Labs invents the practical silicon solar cell (1954) |
| Energy Crisis Era | 1973 – 1989 | Oil shocks trigger the first solar policy push |
| Grid-Connection Era | 1990 – 2009 | Germany’s feed-in tariffs create a mass market |
| Terawatt Era | 2010 – Today | Solar becomes the cheapest electricity in history |
The Ancient Era (700 BC – 1500 AD): Harnessing the Sun Without Electricity
Humanity’s relationship with solar power began with concentration, not conversion.
7th century BC
People used magnifying glasses to concentrate sunlight and start fires, the earliest documented deliberate use of solar energy.
3rd century BC
Greeks and Romans used polished bronze “burning mirrors” to light sacred torches for religious ceremonies.
Legend holds that Archimedes used mirrors to set Roman ships ablaze during the Siege of Syracuse (212 BC), probably a myth, but a testament to how well the ancients understood concentrated sunlight.
1st–4th century AD
Roman bathhouses were built with large south-facing windows, an early form of passive solar heating.
The concept became so important that the Justinian Code (6th century AD) established “sun rights” guaranteeing citizens access to sunlight.
Ancestral Puebloans (1200s AD)
In what is now the southwestern United States, entire cliff dwellings were oriented to capture winter sun and reject summer heat. Passive solar design was centuries ahead of its time.
Era breakthrough
Concentrated and passive solar design proved that solar energy was valuable long before anyone knew what an electron was.
The Early Scientific Era (1767 – 1839): The Photovoltaic Effect Is Born
The Enlightenment brought the first scientific instruments built specifically to capture solar heat.
1767
Swiss scientist Horace-Bénédict de Saussure built the world’s first solar collector, an insulated “hot box” of glass layers that reached temperatures above 100°C. It’s considered the ancestor of every solar oven and solar thermal collector.
1839
The pivotal moment in the entire history of solar energy. Nineteen-year-old French physicist Edmond Becquerel, experimenting in his father’s laboratory, observed that certain materials produced a small electric current when exposed to light.
He had discovered the photovoltaic effect, the physical principle behind every solar panel ever made.
Era breakthrough
Becquerel’s photovoltaic effect (1839). Without this discovery, there is no solar industry.
The Selenium Era (1873 – 1904): The First Working Solar Cells
For decades, the photovoltaic effect remained a laboratory curiosity until selenium changed everything.
1873
English engineer Willoughby Smith discovered that selenium’s electrical conductivity increased when exposed to light (photoconductivity).
1876
William Grylls Adams and Richard Evans Day proved that selenium could generate electricity directly from light, without heat or moving parts: solid-state solar power.
1883
American inventor Charles Fritts built the first true solar cell by coating selenium with an ultra-thin layer of gold. Its efficiency? Roughly 1%.
Fritts installed selenium panels on a New York City rooftop in 1884, the first rooftop solar array in history.
At 1% efficiency and high cost, selenium cells couldn’t compete with coal-fired power plants of the era. But the proof of concept was undeniable.
Era breakthrough
Fritts’ selenium solar cell (1883) was the first device to convert sunlight directly into usable electricity.
The Theoretical Era (1905 – 1953): Einstein Explains Why It Works
Scientists could now make solar cells, but nobody understood why light created electricity. That answer earned a Nobel Prize.
1905
Albert Einstein published his paper on the photoelectric effect, proposing that light travels in discrete packets of energy (photons) that can knock electrons loose from atoms.
This work on relativity, not relativity, won him the 1921 Nobel Prize in Physics, and it gave solar energy its theoretical foundation.
1918
Polish chemist Jan Czochralski developed a method for growing single-crystal silicon, the same fundamental process still used to manufacture monocrystalline solar panels today.
1940
Russell Ohl at Bell Labs discovered the p-n junction in silicon, the structural heart of the modern solar cell.
Era breakthrough
Einstein’s photoelectric theory (1905) was the physics that made engineered solar cells possible.
The Silicon Era (1954 – 1972): The Modern Solar Cell Arrives
This is the era every solar professional considers the true birth of our industry.
April 25, 1954
Bell Labs researchers Daryl Chapin, Calvin Fuller, and Gerald Pearson unveiled the first practical silicon solar cell, with about 6% efficiency, six times better than selenium.
The New York Times predicted it could lead to “the harnessing of the almost limitless energy of the sun.”
1958
The Vanguard I satellite launched with a small solar array powering its radios. While its battery died in weeks, the solar cells kept working for years. Space became solar’s first commercial market; cost didn’t matter in orbit, only reliability.
1960s
Efficiency climbed to 14%, and virtually every satellite adopted solar power. On Earth, however, solar electricity still costs around $100 per watt, hundreds of times more expensive than grid power.
Era breakthrough
The Bell Labs silicon cell (1954), the direct ancestor of the panels I install on rooftops today.
The Energy Crisis Era (1973 – 1989): Oil Shocks Put Solar on the Policy Map
Geopolitics, not physics, drove this era’s progress.
1973
The OPEC oil embargo quadrupled oil prices and exposed the vulnerability of fossil-fuel-dependent economies. Suddenly, governments cared about solar.
1977
The United States created the Solar Energy Research Institute (now NREL, the National Renewable Energy Laboratory), still the world’s leading solar research center.
1979
President Jimmy Carter installed solar water-heating panels on the White House roof, a symbolic milestone (removed by the Reagan administration in 1986, which tells you how political solar had become).
1980s
Terrestrial applications expanded: solar-powered calculators, remote telecommunications, water pumping in off-grid villages.
Prices fell from ~$100/watt to ~$10/watt by decade’s end. Exxon-funded research had earlier pushed cell costs down specifically for powering offshore oil platforms, one of history’s great ironies.
Era breakthrough
The birth of solar energy policy and dedicated research institutions made solar a matter of national strategy.
The Grid-Connection Era (1990 – 2009): Germany Creates the Mass Market
Solar’s problem was never sunlight; it was scale. This era solved it.
1991
Germany’s “1,000 Roofs” program pioneered subsidized residential grid-tied solar.
2000
Germany’s Renewable Energy Sources Act (EEG) introduced generous feed-in tariffs, guaranteeing solar owners a fixed price for every kilowatt-hour fed into the grid for 20 years. Demand exploded.
2000s
To meet German (and later Spanish and Italian) demand, China built massive solar manufacturing capacity.
Economies of scale kicked in, and the famous “learning curve” of solar, roughly a 20% price drop for every doubling of installed capacity, accelerated dramatically.
2008–2009
Global installed capacity passed 20 GW. Panel prices began the steepest decline in the history of any energy technology.
Era breakthrough
Feed-in tariffs and Chinese manufacturing scale were the combination that transformed solar from niche technology into a global industry.
The Terawatt Era (2010 – Today): The Cheapest Electricity in History
Everything before 2010 was prologue.
2010–2020
Solar module prices fell roughly 90%. The International Energy Agency declared utility-scale solar “the cheapest electricity in history” in many markets.
2016
Mexico’s long-term electricity auctions produced some of the lowest solar prices ever recorded at the time, under $20/MWh at Villanueva and other projects.
Here in Mexico, we enjoy some of the best solar irradiance on the planet, which is why distributed generation under CFE’s net metering scheme keeps growing year after year.
2022
Global cumulative solar capacity passed 1 terawatt, or a thousand gigawatts. The second terawatt arrived in roughly two years, a pace that took five decades the first time.
Today
Solar is the fastest-growing source of electricity worldwide. Mainstream panels exceed 22% efficiency, bifacial modules harvest light from both sides, and perovskite tandem cells have surpassed 33% efficiency in the lab, pointing toward the industry’s next great leap.
Paired with plummeting battery storage costs, solar-plus-storage is now displacing fossil peaker plants outright.
Era breakthrough
Radical cost decline and terawatt-scale deployment of solar stopped being “alternative” energy and became simply energy.
What the History of Solar Energy Teaches Us
Three lessons stand out from nearly three millennia of solar development:
Breakthroughs take decades to commercialize
Becquerel’s 1839 discovery needed 115 years to become the Bell Labs cell, and another 50 to become affordable. The technologies in labs today, perovskites, solar windows, and agrivoltaics, are tomorrow’s rooftops.
Policy and crisis drive adoption as much as science
The oil shocks of the 1970s and Germany’s feed-in tariffs did more for solar deployment than any single laboratory result.
Cost curves are destiny
Solar’s relentless learning curve is the reason I can now design residential systems in San Luis Potosí that pay for themselves in four to five years, something unthinkable when I started in this industry.
The history of solar energy isn’t finished. If the past is any guide, the most transformative chapter is the one being written right now.
FAQ: History of Solar Energy
When was solar energy first used?
Solar energy was first deliberately used around the 7th century BC, when people concentrated sunlight with magnifying glasses to start fires.
Greeks and Romans later used polished “burning mirrors” to light ceremonial torches in the 3rd century BC.
Who discovered the photovoltaic effect?
French physicist Edmond Becquerel discovered the photovoltaic effect in 1839 at just 19 years old, observing that certain materials generated a small electric current when exposed to light. This discovery is the scientific foundation of all modern solar panels.
Who invented the first solar cell?
Charles Fritts built the first working solar cell in 1883 by coating selenium with a thin layer of gold, achieving about 1% efficiency.
The first practical solar cell, the silicon design still used today, was invented at Bell Labs in 1954 by Daryl Chapin, Calvin Fuller, and Gerald Pearson.
Why was the 1954 Bell Labs solar cell so important?
The Bell Labs silicon cell reached roughly 6% efficiency, six times better than earlier selenium cells, making solar electricity practical for the first time.
It powered the space program starting with Vanguard I in 1958 and is the direct ancestor of every modern solar panel.
How much have solar panel prices dropped over history?
Solar electricity cost around $100 per watt in the early 1970s. Today, modules sell for under $0.30 per watt, a decline of more than 99%, making utility-scale solar the cheapest source of new electricity in most of the world.
What is the next breakthrough in solar energy?
Perovskite tandem cells are the most promising near-term breakthrough, exceeding 33% efficiency in laboratory settings compared to about 22% for mainstream silicon panels. Combined with cheaper battery storage, they could define the next era of solar history.
