Niagara Falls hydroelectric plant

In August 1895 the Adams Power Station at Niagara Falls, New York, began producing electricity from the falls' water, and on November 16, 1896 it sent power about 26 miles to the city of Buffalo. The plant eventually had ten generators of 5,000 horsepower each, built by Westinghouse and based on Nikola Tesla's polyphase alternating current patents. The financier Edward Dean Adams led the project, and an international commission chaired by Lord Kelvin advised on its design.¹²

The 1880s 'War of the Currents' pitted Edison's direct current, which could not travel more than a mile or two economically, against Westinghouse and Tesla's alternating current, which transformers could step up to high voltage for long-distance transmission. Niagara had enormous power, but it had no way to deliver it, so the plant was the test. After the First Central Power Station of 1882 had shown that central generation worked, the commission considered compressed air and direct current too, before choosing AC. General Electric, Edison's successor, built the transformers and lines to Buffalo, so both camps contributed.²

Niagara showed that power plants could be placed far from the cities that used them, wherever water, coal or other fuel was cheap. Power from the falls attracted electrochemical and aluminum industries to Niagara, and soon electric grids spread. Alternating current became the global standard, and hydroelectric dams became a symbol of modern engineering, from Hoover Dam to the Three Gorges. Many later grids operate at 50 or 60 hertz, and the original Niagara plant used 25 hertz.¹