Facing the need to reduce greenhouse gas emissions while meeting growing electricity demand, renewable energy sources are becoming more central to global energy strategies. Among these, hydropower stands out for its long history and versatility. Unlike newer technologies, hydropower has been used to generate electricity for over a century and remains one of the world's largest sources of renewable power. It works by converting the energy of moving water into electricity. A turbine is turned by the force of flowing water, which then drives a generator to produce electricity. While the concept may seem simple, the installations used to harness this energy vary widely. Large hydropower plants use massive dams and reservoirs to store water, releasing it as needed to generate electricity. In contrast, run-of-river plants use the natural flow of a river or stream with minimal storage. Smaller hydropower installations, often built on existing waterways or old hydraulic structures, provide electricity in more localized settings. This variety allows hydropower to adapt to different geographical and water resource conditions. One of its key benefits is its low carbon footprint. Unlike fossil fuel power plants, which emit large amounts of carbon dioxide during operation, hydropower does not require burning fuel. It also has a long lifespan, with many facilities operating for decades with proper maintenance and upgrades. Beyond its environmental advantages, hydropower offers flexibility that is valuable in modern electricity systems. As renewable sources like wind and solar become more common, their intermittent nature—depending on weather conditions—poses challenges for grid stability. Hydropower can help by adjusting its output to match electricity demand. Plants with reservoirs can store water and release it to generate more power when needed. Pumped-storage hydroelectric power plants (PSH) take this a step further by using excess electricity to pump water uphill into a reservoir, then releasing it to generate power during peak demand. These systems act as large-scale energy storage solutions, becoming increasingly important as more variable renewable sources are integrated into the grid. However, hydropower is not without its environmental challenges. Building large dams can disrupt watercourses, affect natural habitats, and interfere with fish migration. Large reservoirs may also submerge land or alter ecosystems. Climate change adds complexity, as shifts in precipitation patterns and droughts can impact water availability and hydropower production. Managing water resources effectively requires balancing energy needs with other uses like drinking water, agriculture, and ecosystem preservation. To address these concerns, efforts are focused on modernizing existing infrastructure, improving turbine efficiency, and using ecological continuity measures to reduce the need for new dams. By leveraging these strategies, hydropower can continue to play a strategic role in the transition to a more sustainable energy future.