The primary source of energy for solar power is sunlight. Solar power technology harnesses energy from the sun's rays using solar panels, which contain photovoltaic cells. These cells convert sunlight directly into electricity through the photovoltaic effect. Solar thermal systems also utilize sunlight to heat fluids for various applications, such as heating water or generating steam for electricity production. As a clean and renewable energy source, solar power is increasingly being integrated into energy systems worldwide, contributing to reduced greenhouse gas emissions and sustainable development.