The vast majority of energy on Earth originates from the Sun, fueling nearly all life and driving planetary processes. The Sun powers the entire solar system, warming planets, driving weather patterns, and sustaining life on Earth. Understanding this magnitude requires quantifying the total energy. There is so much solar energy hitting the earth's surface that even a single year of sunshine exceeds all known energy reserves of oil, coal, natural gas and uranium put together. **Water,** which is not only essential for life, but which can also be harnessed for energy production.