By John Perlin, author of Let It Shine*

The solar cell had its birth in 1873, as bars of selenium. When two British scientists, William Grylls Adams and Richard Evans Day, in 1876 exposed the bars to candlelight they discovered something totally new: that light, not heat, could directly generate electricity in certain materials such as selenium. Adams and Day called the current produced this way, “photoelectric.” But try as they may, no one could increase selenium’s low conversion of sunlight into electricity and scientists concluded that to realize the vision of solar cells powering the world would require finding a new photovoltaic material.

That came when the collaborative effort of Daryl Chapin, Calvin Fuller and Gerald Pearson at Bell Laboratories developed a photovoltaic device capable of converting enough sunlight directly into electricity to generate useful amounts of power. Their public display at Bell’s press conference on April 25, 1954 of a 21-inch Ferris wheel spinning round and round powered by the first watt of silicon solar cells presented to the world one of the most significant breakthroughs ever recorded in the history of solar energy and of electricity. The New York Times realized the importance of what its reporters saw, stating on its front page that the invention of the Bell silicon solar cell marked “the beginning of a new era, eventually leading to the realization of one of mankind’s most cherished dreams – the harnessing of the almost limitless energy of the sun for the uses of civilization.” US News and World Report speculated that the new solar cell “may provide more power than all the world’s coal, oil and uranium…[its] future is limitless.”

At the time of the Bell announcement in 1954, all the solar cells in the world delivered about one watt. Today, more than 100 billion watts of generating capacity of photovoltaics have been installed worldwide. This year not only marks the 60th anniversary of the silicon solar cell but also the beginning of reaching the Holy Grail solar scientists had only previously dreamt of – entering the Era of Grid Parity Era, where solar panels generate power at costs equal to or less than electricity produced by fossil fuels and nuclear. With the phenomenal growth of solar PV in the last several years and its future even brighter, the time is ripe to celebrate the founding of a technology that led Science magazine almost forty years ago to declare, “If there is a dream solar technology, it is photovoltaics — solar cells…a space-age electronic marvel at once the most sophisticated solar technology and the simplest, most environmentally benign source of electricity yet conceived.”

*The material for the article comes from John Perlin’s recently published book, Let It Shine: The 6000-Year Story.