Tidal energy is a form of hydropower that converts the kinetic and potential energy of tides into electricity. Unlike wind or solar, tidal energy is highly predictable due to the astronomical nature of tides (gravitational pull of the Moon and Sun). Technologies include tidal stream generators (similar to underwater wind turbines) and tidal barrages (dam-like structures).
Tide mills date back to the Middle Ages in Europe. The first large-scale modern tidal power plant opened in La Rance, France, in 1966. It remained the largest in the world until the Sihwa Lake Tidal Power Station opened in South Korea in 2011.
Adoption has been slower than wind/solar due to high installation costs, limited suitable sites, and harsh marine environments. However, it remains a key component of future baseload renewable energy strategies, particularly in the UK, Canada, and China.