Ancient Solar Usage (Pre-20th Century):

• Passive Solar Design: Early civilizations, such as the ancient Greeks and Romans, used passive solar design principles to capture and store solar heat for buildings. South-facing buildings with large windows were designed to maximize sunlight and warmth.
• Solar Cooking: The use of solar energy for cooking dates back to ancient times. People in various regions used reflective surfaces to focus sunlight onto cooking pots.

19th Century:

• Photovoltaic Effect: In 1839, French physicist Alexandre-Edmond Becquerel discovered the photovoltaic effect, which is the basis for modern solar panels. He observed that certain materials generate a small electric current when exposed to light.

Early 20th Century:

• Invention of the Solar Water Heater: In 1909, American inventor William J. Bailey patented a solar water heater that used copper coils and black paint to absorb sunlight and heat water. This invention paved the way for solar water heating systems.

Mid-20th Century:

• First Practical Solar Cells: Bell Labs introduced the first practical photovoltaic (PV) cell in 1954. These early solar cells were used primarily for space exploration, including powering satellites and the Apollo missions.
• Solar Water Heating Boom: Solar water heating gained popularity in the United States during the 1950s and 1960s, especially in regions with abundant sunlight.

Late 20th Century:

• Energy Crisis: The oil crises of the 1970s spurred interest in renewable energy sources, including solar power, as a means to reduce dependence on fossil fuels.
• Advancements in PV Technology: Throughout the latter half of the 20th century, significant advancements in photovoltaic technology were made, making solar panels more efficient and cost-effective.

21st Century:

• Solar Power Expansion: Solar power installations have seen explosive growth in the 21st century, driven by decreasing costs, government incentives, and growing environmental awareness.
• Solar Farms and Grid Integration: Large-scale solar farms have been developed to generate electricity for homes, businesses, and the grid. Innovations in energy storage (e.g., batteries) have helped integrate solar power into the grid more effectively.
• Solar Power Records: Solar power has set records for efficiency and cost-effectiveness. Breakthroughs in materials science and manufacturing processes continue to improve the efficiency of solar panels.
• Global Adoption: Solar power has become a global phenomenon, with countries around the world investing in solar energy as a clean and sustainable source of electricity.