A complete history of solar energy and its discovery

The origins of solar energy arguably date back to the 7th century BC years when magnifying glasses were used to burn ants ¹. Later in the 3rd century BC, the Greeks and Romans reportedly used the sun’s rays via mirrors to light torches for religious ceremonies ².

Today, solar energy leads the charge of the world’s renewable energy mix. The uptake of solar panels is strong, with over 3.9 Million households and small business installing solar in Australia.

We take a look at the history and evolution of solar energy, its discovery and the key personnel who invented solar panels.

Sources: ¹ and ² US Department of Energy: History of solar

Who discovered solar energy?

Despite early accounts of the sun producing energy, it wasn’t until 1839 when the photovoltaic effect was first discovered by a young French scientist, Edmond Becquerel. The photovoltaic effect is the underlying process by which solar panels work. For Becquerel’s part, he is credited with the discovery of solar energy.

The Becquerel effect

At the early age of 19, Becquerel coated electrodes with silver chloride (AgCl) and silver bromide (AgBr) in an acidic solution, which generated voltage and current. The significance of Becquerel’s experiments mean that the photovoltaic effect is sometimes referred to as the “Becquerel effect”.

Edmond Becquerel, who in 1839 discovered solar energy.

Who invented solar panels?

Becquerel’s discovery was the cornerstone moment in the history of solar energy, though other key figures played a significant role in the evolution of solar panels.

Willoughby Smith discovers that selenium is an effective material for electrical conductivity

In 1873, English electrical engineer Willoughby Smith, discovered that selenium had electro conductive qualities when fused with light.

William Grylls Adams uses selenium to create electric current

English Professor William Grylls Adams and his student Richard Evans Day bear witness to the photovoltaic effect in action after exposing selenium to light and producing an electric current.

However, Adams’ selenium solar cells didn’t generate enough electricity from the sunlight it captured. Nevertheless, it was a big step forward; Adams and Day had managed to generate electricity without moving parts.

Charles Fritts installs solar panels on a rooftop

In 1884, solar panels were first installed on rooftops a year after American inventor Charles Fritts developed the selenium cell in 1883. For reference, this was a dozen years before the launch of the modern Olympics, and 17 years before the Federation of Australia.

A photo of the first rooftop solar panels installed on a New York building in 1884.

Following these developments, many people are credited with the improvement of the solar cell and its efficiency, as detailed in our timeline of solar energy below. Credit for the invention of solar panels, firmly lies with Edmond Becquerel, Willoughby Smith, William Grylls Adams and Charles Fritts.

Timeline of solar energy: The key moments

Edmond Becquerel, who had the audacity to fool around in his father’s laboratory and understand the photovoltaic effect, is largely responsible for the solar energy movement. However, there have been many significant events and milestones that timeline the history of solar energy from Becquerel’s discovery to the present day.

1839 – Edmond Becquerel discovers the photovoltaic effect

Edmond Becquerel, a 19-year old Frenchman, discovers the photovoltaic effect when he generates electricity using sunlight.

1884 – Solar panels first installed on a rooftop

It was the ingenious idea of American inventor Charles Fritts to put solar panels on a rooftop, however, there was a problem. In fact, this problem was so consequential that it would prove to be a major obstacle for scientists for over a century. Fritts’ panels, while technologically sound for the time, were terribly inefficient, with an efficiency of less than 1% ³. They were not an economically viable source of solar energy generation.

Source: ³ American Physical Society (APS),

1979 – US President Jimmy Carter installs solar panels on top of the White House

The invention of solar cells came 100 years before US President Jimmy Carter installed 32 solar panels on top of the White House in 1979. However, Carter’s renewable intervention didn’t last long, President Reagan dismantled the installation and removed the panels in 1986.

Jimmy Carter proudly showing reporters solar panels at the White House in 1979.

1985 – Solar cells with 20% efficiency developed in Australia

A team from The University of New South Wales’ (UNSW) Centre for Photovoltaic Engineering develops silicon solar cells that achieve efficiency greater than 20%. Australian professor Martin Green, who led the team, described the moment as “the equivalent of the four-minute mile of photovoltaics”.

2019 – Solar efficiency reaches nearly 40% in laboratory conditions

It took until 2019, nearly 135 years after Charles Fritts’ installed the first rooftop solar panel, before silicon cells were able to be manufactured at near 40% efficiency. In 2019, the world record for solar cell efficiency had climbed to 39.2%, which was achieved by using multi-junction concentrator solar cells, developed at National Renewable Energy Laboratory in Colorado, USA.

Fun fact: The high-achieving Becquerel family

Edmond Becquerel wasn’t the only high achiever in his family. Edmond’s father, Antoine, was a scientist in his own right in the field of electric and luminescent phenomena and Edmond’s son, Henri, continued the family’s legacy by becoming a physicist, Nobel laureate, for his work and discovery of spontaneous radioactivity. Suffice to say, the Becquerel family did their bit when it came to advancing science!

The future of solar panels

All of the trailblazers listed in this article, from Becquerel to the UNSW have advanced solar panel technology. The future of solar power is not only bright, but essential. Solar panels have many benefits and, in most instances, can significantly reduce electricity bills and provide a great return on investment.

Energy generated from solar increased 26% globally in 2022 and now accounts for more than 4.5% of electricity generation ⁴.

Source: ⁴ International Energy Agency solar findings

In Australia

Well over 30% of Australian households have installed solar panels. Globally, this positions Australia as a household leader of adopting solar technology, but a terrific opportunity lies for many who are yet to install solar panels at their home.

As the need to store renewable energy and electrify our households increases, it is expected the uptake of solar batteries will increase significantly in coming years.