Since time immemorial, humans have looked to the sky for answers, warmth, or light. The sun, an inexhaustible source of energy, has always been an object of admiration and exploitation in different cultures. However, it has only been in recent centuries that we have understood, studied, and developed technologies capable of transforming that light into useful electrical energy through the use of solar panels. solar.
The evolution of solar panels is a fascinating story marked by scientific discoveries, technological advances, and revolutionary innovations.From the beginning with simple mirrors and solar ovens to modern solar panels capable of achieving efficiencies exceeding 22%, this tour showcases human ingenuity at the service of sustainability and the environment.
The first uses of the sun as an energy source
Long before the discovery of the photovoltaic effect, various civilizations were already harnessing solar energy in ingenious ways.By the 3rd century BC, the ancient Greeks were already using concave mirrors to concentrate sunlight onto objects to light fires, a technique even attributed to Archimedes during the Battle of Syracuse, where he supposedly used mirrors to set fire to the Roman fleet.
In ancient Rome, faced with a shortage of wood, buildings were developed that faced the sun to capture heat. The Romans used glass in the windows of their homes to retain heat., and they also created greenhouses, known as glass houses, where they grew exotic plants thanks to the constant temperature generated by sunlight. This aspect of solar architecture is invaluable when talking about comfort at home.
Over time, they perfected solar architecture. A legal right to access sunlight was established, homes were designed to be oriented according to the seasons, and inventions such as the heliocaminus, a solar oven that harnessed the sun's energy to heat interior spaces or cook food.
In the Americas, the Anasazi, an American Indian civilization from the southwest of North America, designed homes and settlements oriented toward the sun to benefit from its light and heat.They lived in adobe and stone dwellings, strategically located on south-facing cliffs, which provided them with natural warmth during the winter. This architectural approach is now considered a precursor to solar urbanism.
Centuries of scientific experimentation: The photovoltaic effect
It was in the 1767th century that science took its first steps toward modern solar energy. In 100, Swiss naturalist Horace Bénédict de Saussure created the first solar oven, a glass box that concentrated the sun's heat and reached temperatures exceeding XNUMX°C, allowing food to be cooked efficiently.
In 1839, French physicist Alexandre-Edmond Becquerel discovered the photovoltaic effect, observing that certain materials produced an electric current when exposed to light. This fundamental discovery laid the groundwork for the future development of solar cells. This principle is fundamental to understanding current solar efficiency.
Later, in 1866, Augustin Mouchot built the first parabolic solar collector, which used mirrors to concentrate the sun's rays and produce steam that drove an engine. This invention paved the way for solar thermal energy.
The first solar panels: From theory to practice
In 1883, Charles Fritts manufactured the first solar panel using selenium coated with gold leaf. Although it was only 1% efficient, it was a decisive step forward. In 1891, Clarence Kemp developed the first solar water heater, a glass box that heated a tank of black water.
In 1905, Albert Einstein gave a theoretical explanation of the photoelectric effect, and in 1921 he was awarded the Nobel Prize for it. In 1916, Robert Millikan experimentally validated this theory, scientifically consolidating the phenomenon. This development was crucial for the knowledge needed in evaluate costs and performance.
In 1953, Dan Trivich performed theoretical calculations on the efficiency of solar cells made from different materials. A year later, in 1954, Bell Labs introduced the first silicon solar cell with an efficiency of 4%. Its creators, Daryl Chapin, Calvin Fuller, and Gerald Pearson, laid the foundation for the modern solar panel.
Solar energy in space and its expansion to Earth
The first practical use of these panels was in space. In 1958, the Vanguard 1 satellite was launched, the first to use solar power, allowing it to operate for six years in orbit.
In 1963, the first photovoltaic-powered lighthouse was installed in Ogami, Japan, marking the beginning of terrestrial applications of this technology. That same year, Sharp began mass industrial production of solar panels in that country. This breakthrough opened the door to new solar panel systems.
Over the next two decades, technology advanced rapidly, and in 1970, NASA donated panels to the Papago tribe as part of a pilot project. In 1981, Paul MacCready developed the first solar-powered airplane.
Technological advances and improved efficiency
In 1985, a team at the University of New South Wales achieved the first silicon cell with an efficiency exceeding 20%. In 1993, the first grid-based distributed energy system was installed in Kerman, California.
During the 90s and 2000s, materials were refined: monocrystalline and polycrystalline silicon cells were developed, as well as thin-film technologies, which reduced costs and improved efficiency and flexibility. This advancement was crucial for the solar panel installation.
In 1998, Subhendu Guha invented flexible silicon solar tiles, and in 2005, the first DIY solar panels appeared, easy to assemble and designed for developing regions.
Generations of solar cells and emerging technologies
Currently, there is talk of several generations of photovoltaic technologyThe first is based on crystalline silicon with efficiencies of around 15-20%. The second includes thin-film cells, which are lighter and cheaper, although slightly less efficient.
The third generation relies on materials such as carbon nanotubes, quantum dots, or dye-sensitive cells (DSSC), with potentials exceeding 30% and great versatility in formats such as solar paints or semi-transparent panels. This is relevant when considering new solar applications.
The future fourth generation will combine polymers and nanoparticles in multispectral layers to capture different wavelengths, including infrared. This will allow convert even waste heat into electricity, maximizing efficiency.
Social, economic and ecological impact
The use of solar panels has transformed the way we generate and consume energy. They have been key to electrify rural areas, provide access to clean water through solar pumps, and reduce our dependence on fossil fuels. This impact is fundamental when analyzing environmental impact.
Today, they are found in homes, buildings, vehicles, satellites, and even space stations. They are also widely used for signaling, telecommunications, cathodic protection, and medical care in remote locations.
Furthermore, their cost has dropped dramatically. According to studies, the price per watt of solar panels has dropped from over $70 per watt in 1977 to less than $0,25 today. This trend is due to Swanson's law, which states that every time production doubles, the cost drops by 20%.
The present and future of solar energy
New technologies such as N-Type TOPCon cells are currently being used., which combine tunnel oxide with PERC semiconductors to increase efficiency and reduce electron recombination. The most modern models now exceed 500W per panel, with efficiencies exceeding 22% in commercial products.
Research continues to innovate in new materials such as perovskites, graphene, and hybrid solutions. The trend is toward lighter, more powerful panels with full architectural integration: solar facades, photovoltaic windows, and even solar textiles. This advance is important for transparent solar panel technology.
The goal is to achieve clean, autonomous, fully decentralized and affordable energy.Solar energy is emerging as one of the major players in the energy transformation that will define the coming decades.
The evolution of solar panels is the result of centuries of curiosity, observation, invention, and scientific perseverance. From ancient Greek mirrors to space satellites, and from rudimentary solar ovens to cutting-edge photovoltaic cells, the sun has been and will continue to be one of our greatest allies. Today, more than ever, solar energy is not just an alternative, but an urgent need and a real opportunity to advance toward a cleaner, more equitable, and more efficient society.
