The History of Solar PV 

Solar power often feels like a modern technology, but the idea of capturing the sun’s energy has been around for thousands of years. From ancient mirrors to today’s silicon panels, the story of solar PV is one of steady progress shaped by science, engineering and the need for cleaner energy. 

Ancient experiments 

The earliest evidence dates back to the 7th Century BC, when magnifying glass was used to c oncentrate sunlight and start fires. Ancient Greeks and Romans developed the technique further, lighting torches with mirrors. 

Legend even claims Archimedes once used polished shields as a “heat ray” to set enemy ships ablaze during the Siege of Syracuse. Whether true or not, it shows how long humans have tried to harness the sun. 

The first solar cell 

The first real collector came in 1767, when Swiss scientist Horace de Saussure created a glass box trap that reached over 110°C. This “hot box” became the foundation of later experiments. 

In the 1830s, astronomer John Herschel used a similar device in South Africa to cook food, while in the 1860s, French mathematician Augustin Mouchot designed the first solar-powered steam engines. 

Scientific breakthroughs 

A key discovery came in 1839 when French physicist Edmond Becquerel identified the photovoltaic effect — light could increase electric current between electrodes. 

In 1883, Charles Fritts built the first solar cell using selenium coated in gold. It was only 1% efficient but proved electricity could be generated directly from sunlight. 

The science accelerated in the early 20th century. Albert Einstein won a Nobel Prize in 1921 for explaining the photoelectric effect, which underpins modern PV cells. 

Towards modern panels 

By 1908, William J. Bailley had invented a copper coil solar collector, similar to systems used today. In 1946, Russell Ohl patented the silicon solar cell, a step that paved the way for both PV panels and modern LED lighting. 

In 1954, Bell Labs produced the first PV cell capable of powering electrical equipment, reaching 11% efficiency within a few years. These were soon adopted by NASA, first powering the Vanguard I satellite. 

Costs fell in the 1970s, boosting commercial use. Projects like Solar One and Solar Two in California proved large-scale generation was possible and that energy could be stored for when the sun wasn’t shining. 

For a more practical look at how technology adoption drives demand for skills, see EV Charging Growth Sparks Demand for Skilled Electricians. 

Solar PV today 

Today more than 1.3 million UK homes have solar panels, supported by schemes such as the Smart Export Guarantee. Panels not only cut bills but can feed u nused energy back to the National Grid. 

But growth comes with challenges. Solar waste could hit 78 million tonnes worldwide by 2050, which means recycling and decommissioning will become just as important as installation. 

For electricians, solar PV is now a mainstream skill. Training pathways are adapting, combining health and safety foundations such as Access Equipment Lesson 13 and Access Equipment Lesson 14 with renewable energy modules. 

And while most installs are safe, poor work still makes headlines. See Halloween Hall of Horrors: The Scariest Electrical Installs We’ve Seen for why competence and training matter more than ever. 

Looking ahead 

Solar PV has evolved from ancient mirrors to high-efficiency silicon cells in satellites, homes and businesses. As technology improves and demand for clean energy grows, electricians will play a key role in the rollout. 

At Elec Training, we help learners build the skills to work safely and effectively in renewables. Visit Elec Training to explore training that prepares you for the next stage of the solar journey. 

When was the photovoltaic effect first discovered? 

The photovoltaic effect, the process by which light generates electricity in certain materials, was first discovered in 1839 by French physicist Edmond Becquerel during experiments with electrolytic cells, where he observed that exposing silver chloride e lectrodes to light produced a voltage. This foundational observation laid the groundwork for modern solar technology, though it wasn’t practically applied until later developments. Becquerel’s work, conducted at age 19 in his father’s lab, involved wet cells and marked the earliest recognition of light-induced electrical currents, predating later selenium-based experiments by Willoughby Smith in 1873. By 2025, this effect underpins global solar PV capacity exceeding 1 TW, highlighting its enduring impact on renewable energy. 

Who built the first solar cell and how efficient was it? 

The first solar cell was built by American inventor Charles Fritts in 1883, who coated selenium with a thin layer of gold to create a device that converted about 1% of sunlight into electricity. This early prototype, while groundbreaking, was inefficient and costly compared to coal power, limiting its practical use at the time. Fritts’ invention built on prior discoveries like the photovoltaic effect and selenium’s photoconductivity, but it wasn’t until Bell Labs’ 1954 silicon cell (6% efficiency) that more viable applications emerged. In 2025, this historical milestone contrasts with modern panels exceeding 20% efficiency, underscoring rapid advancements in PV technology. 

Did ancient civilisations really use sunlight for practical purposes? 

Yes, ancient civilizations harnessed sunlight for practical purposes, including heating homes, cooking, water heating, and even warfare, demonstrating early solar energy utilization long before modern technology. For instance, Greeks and Romans oriented buildings southward for passive solar heating, while Egyptians used sun-dried bricks and reflective surfaces for light amplification. Legends like Archimedes’ “death ray” (burning mirrors in 212 BCE) suggest focused sunlight for defense, and Chinese cultures employed concave mirrors for fire-starting as early as the 7th century BCE. By 2025, these ancient practices inspire contemporary passive solar designs, highlighting sunlight’s timeless utility in architecture and daily life. 

What role did Albert Einstein play in the development of solar power? 

Albert Einstein played a pivotal role in solar power development by explaining the photoelectric effect in 1905, describing how light ejects electrons from metals as quantized photons, which earned him the 1921 Nobel Prize and provided the theoretical foundation for photovoltaic cells. This insight revolutionized quantum physics and directly enabled solar cell design, as photons’ energy converts to electricity in PV materials. While not an inventor, Einstein’s work bridged classical and quantum theories, influencing later innovations like Bell Labs’ 1954 silicon cell. In 2025, his legacy persists in efficient solar tech driving global renewables. 

When was the first silicon solar cell invented? 

The first silicon solar cell was invented in 1954 by Daryl Chapin, Calvin Fuller, and Gerald Pearson at Bell Laboratories, achieving about 6% efficiency and marking a practical breakthrough in photovoltaic technology. Demonstrated on April 25, 1954, in Murray Hill, New Jersey, it powered a toy Ferris wheel and radio, evolving from earlier selenium cells and paving the way for space and terrestrial applications. By 2025, this invention underpins over 90% of global solar panels, with efficiencies now exceeding 20%. 

How did NASA use solar PV in early space missions? 

NASA first used solar PV in the Vanguard 1 satellite launched in 1958, which featured six small silicon solar cells generating 1 watt to power its radio transmitter, marking the earliest spacecraft to rely on photovoltaics for long-term operation. This success extended mission lifespans beyond battery limits, influencing subsequent probes like Explorer 6 (1959) with larger arrays. By the 1960s, solar became standard for near-Earth missions, powering communications and instruments in extreme environments. In 2025, NASA’s advancements continue with high-efficiency cells for deep space, building on these early integrations. 

When did solar power first become commercially viable? 

Solar power first became commercially viable in the 1970s, spurred by the oil crisis and falling costs, with early applications in remote calculators and offshore platforms, though widespread grid parity emerged in the 2010s as prices dropped below $1/watt. Initial silicon cells from 1954 were too expensive ($300/watt in 1956), but government acts like the 1974 U.S. Solar Energy Research Act accelerated adoption. By 2025, solar’s viability is global, with costs at $0.30/watt driving terawatt-scale deployments. 

How have solar panel efficiency levels changed over time? 

Solar panel efficiency has dramatically improved from about 1% in Charles Fritts’ 1883 selenium cell to over 22% in 2025 commercial monocrystalline silicon panels, with lab records reaching 47.6% for multi-junction cells. Key milestones include Bell Labs’ 6% in 1954, 10% thin-film in 1980, and 20%+ by the 2010s, driven by material advancements and economies of scale. Degradation rates remain low at 0.5% annually, ensuring 80-85% output after 25 years, fueling solar’s 2025 dominance in renewables. 

What major projects helped prove large-scale solar generation was possible? 

Major projects proving large-scale solar viability include the 2.8 GW Golmud Solar Park in China (world’s largest as of 2025), the 864 MW Edwards & Sanborn in California with storage, and the 900 MW SB Orion Solar Belt in Texas, demonstrating gigawatt-scale integration and grid stability. Early pioneers like the 354 MW Ivanpah CSP in 2014 showcased concentrated solar, while the U.S. DOE’s database tracks over 8,100 projects totaling 339 GWdc, affirming solar’s scalability for clean energy transitions. 

How widespread is solar PV use in the UK today compared to its early adoption? 

Solar PV use in the UK has grown exponentially from early adoption in the 2000s (under 100 MW) to over 15.8 GW installed capacity by mid-2025, with 1.5 million homes equipped and generation hitting a record 9.91 TWh in the first half of 2025—up 32% year-on-year. Domestic installations rose 22% in early 2025, driven by schemes like the Smart Export Guarantee, contrasting with minimal early uptake before Feed-in Tariffs in 2010. By 2025, solar contributes significantly to the UK’s 100% clean electricity goals, far surpassing initial pilots.