Sustainability Insights

The world today follows many paths of sustainability, like renewable-based electricity generation, energy-efficient appliances, and lower emissions in Industries. Solar energy has played a significant role in the sustainability journey. The sun’s energy has been harnessed from time immoral by the humans.

Using Solar Energy goes back to the 7th Century B.C. when the Sun’s rays were collected through magnifying glasses to make fire and burn ants. Burning mirrors were used to light torches from 3rd Century B.C. onward. In 1767, the world’s first solar collector was built and was later used for cooking during an expedition in 1830. In 1891, the first commercial solar water heater was patented. After World War II, passive solar buildings gained popularity.

The solar photovoltaic history roots in 1839. Alexandre-Edmond Becquerel observed a voltage generated by sunlight exposure on metal plates for the first time. In 1873, selenium’s light sensitivity was discovered and in 1880s, the first selenium solar cells were created by Charles Fritts. The conversion efficiency was 1%.

A major breakthrough was in 1950s. Three scientists at Bell Telephone Laboratories (Calvin Fuller, Daryl Chapin, and Gerald Pearson) developed a photovoltaic cell using extrinsic semiconductors. Their research achieved about 6% efficient solar cells. This was first presented in 1954 and marked the beginning of the commercial use of silicon solar cells. Today, about 22% efficiency is reported for solar panels. The photograph at the left is Bell Solar Module being installed in Americus, Georgia, for powering telephone repeater, April 1956. (Photo source – Solar Compass)

In 2024, solar energy produced about 7% of the total electricity produced globally. Additionally, there are stand-alone or home-based systems that use solar energy. These systems run basic appliances like light bulbs and fans. They are used in parts of the world where electricity is still awaited or where the supply is poor. Solar water heaters have gained popularity, especially in the hospitality industry.

The recently released World Energy Investment Report 2025 mentions about energy investments. Solar energy attracted the largest share of the world’s investment spending on energy in 2025. Solar energy has been harnessed from long for various uses. Today, it is a major hope for providing emission-free energy. This is crucial in the face of rising global temperatures and depleting fossil-based resources.

(Views are personal.)