New Energy World™
New Energy World™ embraces the whole energy industry as it connects and converges to address the decarbonisation challenge. It covers progress being made across the industry, from the dynamics under way to reduce emissions in oil and gas, through improvements to the efficiency of energy conversion and use, to cutting-edge initiatives in renewable and low-carbon technologies.
Golden age: how solar became the world’s cheapest power source
18/3/2026
8 min read
Feature
Solar power has come a long way since 1839, when French physicist Alexandre Edmond Becquerel figured out that directing sunlight onto two electrodes, one covered with silver chloride and the other with silver bromide, generates an electric current. From this humble start, global solar capacity reached 2 TW in 2024, a doubling in just two years. Most of the progress has accelerated in the past few decades, with prices falling by 99.9% since 1975, making solar one of the cheapest forms of electricity generation worldwide, writes Charlie Bush.
These figures would have seemed impossible as recently as the 1990s. Solar’s rise has not been a sudden breakthrough, but the results of nearly two centuries of scientific curiosity, engineering refinement and policy experimentation. Now, the future appears brighter than ever for this renewable energy source.
The photovoltaic effect
The foundations of solar power were laid in 1839, when Becquerel observed that certain materials produced small electric currents when exposed to light. This phenomenon, later termed the photovoltaic effect, was scientifically intriguing but practically insignificant at the time. The currents were weak, and materials science was still in its infancy. Moreover, the invention of the internal combustion engine in the mid-nineteenth century turned industrial attention towards fossil-fuel-based mechanical power rather than sunlight.
Another milestone was passed in 1873, when the English electrical engineer Willoughby Smith discovered that selenium exhibited photoconductivity. Building on this, in 1883, the American inventor Charles Fritts constructed what is often regarded as the first true solar cell, using selenium coated with a thin layer of gold. Its efficiency was below 1%, but the principle was established.