The use of flowing water as a source of energy has been exploited for hundreds of years, with traditional water mills powering early industrial processes. Turbines are the modern equivalent of a water mill but run at much higher energy efficiency due to the efforts of engineer James Francis (1815-1892), who invented the Francis turbine, and whose calculations enabled modern, super-efficient turbines to be built, allowing clean, renewable energy production.
The first large-scale turbine for power generation was built by Benott Fourneyron in 1827. His invention was an out-flow design, but it took another ten years for him to stabilize the turbine, at which point he managed 80 percent efficiency—that is, the turbine could usefully extract 80 percent of the kinetic energy theoretically contained within the running water.
Francis, an English engineer, moved to the United States to work for the proprietors of Locks and Canals Company in Lowell, Massachusetts. He began to study the hydraulics of turbines in detail and conducted many experiments into its properties. This extensive analysis led him to design a far more efficient inward- flow, reaction turbine than had been created previously—his invention reached upward of 90 percent efficiency. The turbine worked on the principle that, as the water passes through the turbine, it changes from high to low pressure, and the energy it releases in doing so is transferred to, or mopped up by, the blades of the turbine.
Francis gave his name to the new turbines and led the company for forty years. The new turbines helped transform Lowell into an industrial town. Today, Francis turbines are commonly employed as energy generators in hydroelectric dams and pumped-storage plants across the world.
