The national parks preceded the National Park Service, but the first great natural park was a state park. Californiaâs Yosemite State Park was established in 1864, by a federal cession approved by President Abraham Lincoln, and on October 21, 1880, President Rutherford B. Hayes toured Californiaâs Yosemite in an open carriage.
In fact, humans have been capturing the energy of moving water for thousands of years. Today, harnessing the power of moving water to generate electricity, known as hydroelectric power, is the largest source of emissions-free, renewable electricity in the United States and worldwide.
Turbines and generators convert the energy into electricity, which is then fed into the electrical grid to be used in homes, businesses, and by industry. To see a close up view of how the generator of a water turbine works, see the Hydropower Basics page.ecause the water cycle is an endless, constantly recharging system, hydropower is considered a renewable energy. When flowing water is captured and turned into electricity, it is called hydroelectric power or hydropower.