Electric!
"Sun"
SOUNDS OF BATTLE AT SEA
It is 212 B.C. in Syracuse, Sicily. Rome and Carthage are vying for power over the Mediterranean, and Sicily is siding with the Carthaginians. The wide Roman warships are purposely built that way to make it easier for soldiers to land, and now they are ominously approaching the Sicilian coast.
It seems like nothing can stop them.
But all of a sudden, one of the sails catches fire, and shortly after the other ships are engulfed in flames as well. The Roman army is defeated before it even touches land. What would appear as some sort of a miracle, actually has two possible explanations, both scientifically sound.
Some say credit goes to a famous inventor named Archimedes, who would have built a structure made of 24 large mirrors arranged in a hexagonal shape and attached them to a rotating lattice on a pole. The side mirrors converge the sun's rays on a central mirror, which in turn directs the reflected beam onto the target: the Roman ships.
FIRE
Others say that a thousand women stood in strategic positions in the harbor of Syracuse, while holding just as many bronze mirrors and directing the sun's heat onto the sails of the ships passing through, causing them to catch fire.
VOICES OF WOMEN CELEBRATING
The episode of the burning mirrors is not confirmed by historians. But, history or legend, it has been passed down from generation to generation, a testament to our fascination with the most important star for life on Earth: the Sun.
MUSIC
Intro: I’m Andini Makosinski, and this is Electric!: a podcast that takes you to the fascinating places where we produce one of our most precious resources: energy.
A ROCK ROLLS INTO SPACE
From the earliest times and in every corner of our planet, the Sun has been revered by humans, but it wasn't until the nineteenth century that we began experimenting with how its light could be turned into… electricity.
In the same years, the first coal-fired power plants were born. But the journey of photovoltaic technology is a much longer one.
It was 1839 when an eminent French physicist with a black mustache and ruffled gray sideburns, Alexandre Edmond Bequerel, noticed that the influence of the sun's rays caused slight fluxes and electrical effects on certain liquids. This observation, which might seem like a small one, is the cornerstone for the scientific and technological research that today enables us to capture the Sun’s energy.
In the late 1800s, an American inventor named Charles Fritts discovered that covering selenium with a very thin, semi-transparent film of gold and exposing the combination to the sun's rays produces electricity! This innovation has very low energy efficiency, but it is the very first, rudimentary solar panel!
In 1939, Maria Telkes, a Hungarian scientist, designed the first fully solar-powered house and began to work on a system to store the sun-produced energy.
Finally, in 1954 the first silicon solar cell capable of generating measurable electric power was born. In that year, however, the materials still cost too much, and solar panels are not yet ready to be commercialized.
In 1970, something happens. It’s a big turn of events that, however distant in time, may sound familiar to a lot of us. Because of a war, the price of oil soars from $3 to $12 a barrel. The cost of food rises, the people’s purchasing power declines, and entire manufacturing sectors end up in a deep crisis. Alarmed, governments around the world turn their attention to energy sources that can replace oil. They begin to invest way more in renewable energy, and finally make it possible to bring down the costs that had hindered the spread of photovoltaic technology.
Thanks to those investments, and to the ones we have collectively chosen to make over the years, today we can count on a renewable energy source that is not only much cleaner and produces far less emissions than any fossil fuel, but is also way more democratic ... because no country can stop the Sun from shining.
Intro: I'm Andini Makosinski, and this is Electric!: a podcast that takes you to the fascinating places where we produce one of our most precious resources: energy.
Since Archimedes' studies, through a combination of scientific discoveries, technological advances, political decisions, and even economic crises, we have come a long way. And that road, today, takes us to a giant photovoltaic power plant -- in the heart of Mexico.
MEXICAN MUSIC
In front of us are millions of photovoltaic panels, 2.3 million to be exact, arranged next to each other in neat, long rows stretching into the desert as far as the eye can see. Who knows what Charles Fritts or Maria Telkes would have said if we had brought them here!
These state-of-the-art solar panels are the beating heart of the plant. They are covered with a semiconductor material, silicon, which is sensitive to light. When this surface is hit by solar radiation, it produces electricity through the "photovoltaic effect," one of the phenomena Einstein studied when he won the Nobel Prize in Physics in 1907.
But as anyone who has ever tried to sunbathe on a beach already knows, when dealing with the sun, our position relative to this powerful star can make a big difference. And if it does for a tan, imagine what a difference it can make for 2.3 million photovoltaic panels!
For this reason, the panels are housed on special support structures that, depending on the latitude and time of year, ensure the correct tilt and orientation to maximize light exposure.
All solar panels are connected to an inverter, a machine that can transform the direct current produced by the modules into alternating current, which is easier to transport and use in people’s homes.
BLENDER, HAIR DRYER, WASHING MACHINE...
The technology of this plant is not the only form of solar energy conversion. Solar energy can also be harnessed in "solar thermal power plants" (or “concentrating solar power plants”), where there are no photovoltaic panels, but mirrors - even larger than those used by Archimedes! - that concentrate all the light captured by the sun's rays to a specific point, called a receiver.
The heat is stored in the receiver, which can be used to generate the steam needed to activate the turbines.
The mechanical energy produced by the turbine is then transmitted to the alternator, which converts it into electricity ready to be distributed.
Sounds familiar? That's right, it is the same principle as the coal-fired thermal power plant but here, no combustion is needed to generate electricity.
BEAK
One of the challenges associated with renewable energy generation lies in the fact that the sun does not shine 24 hours a day, because it doesn’t shine at night or on cloudy days. What do we do then?
SUDDEN SILENCE
That’s when we need storage systems. These systems are able to store the energy produced by the sun or wind and make it available when nature rests. As you can imagine, these systems are a critical piece of the transition we are making.
Sometimes we are tempted to think that energy production concerns only large industrial groups, and choices over which we have no say. That is not the case. The scientists who have been instrumental in the development of photovoltaic power plants, are citizens, like you and me. It was the sum of their observations, the sharing of information, ideas and experiments, that brought us this far. And when we decide to install photovoltaic panels on our homes, when we are careful not to consume more energy than we need, just as ordinary citizens, we are making a fundamental contribution to the green transition.
In short, the history of energy is not just the story of great discoveries, of governments negotiating the price of fuels in buildings far away from our homes. It is a collective story that brings together the curiosity of scientists, the competence of politicians, the responsibility of businesses and the choices of citizens.
There are 7.9 billion human beings on Earth, and we all need energy.
Investing in sustainable ways of producing it, and learning not to waste it, is crucial to build a brighter future for all.
CREDITS
Electric! is an original production of Undercats.
And it’s proudly supported by one of the companies that are shaping the future of renewable energy on this planet, Enel Green Power.
The creator of the show is Francesca Cavallo, with editorial consulting of Arianna Giorgia Bonazzi and scientific advisory by Monica Caboni, and by the experts of Enel Green Power.
Electric! is produced by Francesca Cavallo and Alessia Balducci. The theme song and sound design are by Simone Lanza for Glos. Artwork by Elisa Angelico.
If you enjoyed this episode, please leave a review and send it to your friends! And if you have Spanish or Italian speaking friends that you want to share this episode with, know that you can!
Electric! also exists in Italian, it is titled Scintille and it’s read by Francesca Cavallo herself, and in Spanish, with the title Chispas, read by a wonderful fellow inventor from Chiapas Mexico, the very young and uber inspiring Xochitl Guadalupe Cruz.
We'll be back here next week for a new episode of Electric! ciao!