From Gray to Green

Hydropower’s Journey: Transforming from Gray to Green Through Collaboration

Hydropower is one of the world’s oldest renewable energy sources. Early projects were engineering marvels that powered communities and supported economic growth, reflecting the priorities and knowledge of the time.

But many projects came with tradeoffs, impacting river ecosystems, fish populations, and Indigenous lands and lifeways. Over the decades, as understanding of these impacts has deepened, so have efforts to design more sustainable and equitable solutions.

Through ongoing engineering innovations advancing this “gray” infrastructure, hydropower’s environmental performance continues to improve, shaping a greener energy future.

Timeline of milestones and partnerships

Today, through collaboration among industry leaders, tribes, scientists, and conservationists, hydropower is evolving to support both clean energy goals and healthier rivers.

The timeline below was developed as part of the Uncommon Dialogue Working Group on Hydropower, River Restoration, and Public Safety, and it traces the milestones and partnerships that have helped move hydropower toward a greener future.

  • Dam with flowing water

    First Hydropower plant built

    Humans have used water for power for millennia, with the earliest water-powered mills found in ancient Greece, China, and Imperial Rome. However, it was not until the 19th century that hydropower was used to generate electricity.

    In 1849, James B. Francis invented the Francis turbine, a model still widely used today. Around forty years later, in 1882, the world’s first hydropower plant began generating power on the Fox River in Appleton, Wisconsin. In 1887, a second plant opened in San Bernardino, California. (1)

    (1) History. National Hydropower Association. (2019, September 12). https://www.hydro.org/about/history/