Energy is the ability to do work. It exists in various forms, such as kinetic (energy of motion), potential (stored energy), thermal (heat energy), chemical (energy stored in bonds), and so on. Solar energy comes from the Sun and can be harnessed to generate electricity. Every day, the Earth receives a massive amount of energy from the Sun through its rays. Solar power is a renewable energy source, meaning it won’t run out. The solar constant refers to the amount of solar energy reaching a square meter of space just outside Earth’s atmosphere, which is approximately 1.4 kW/m2. However, as sunlight passes through the atmosphere, some of its energy is absorbed and scattered by gases, reducing the power that reaches the surface. Solar energy can be used in different ways, such as heating water or generating electricity. Semiconductor materials like silicon (Si) are used in solar panels to convert sunlight into electricity. These panels contain multiple solar cells, also called ray collectors, which work together to produce more electricity than a single cell. During rainy weather or at night, the electricity generated during the day can be stored in nickel-cadmium (Ni-Cd) batteries or other storage systems. These batteries provide power when sunlight is unavailable, ensuring a steady energy supply.