The first Beck I unit was commissioned on Christmas Day, 1921. Its vertical turbine-generator combination was similar to the design later used in almost all hydraulic stations. Water delivered by an open canal 20 km long from Chippawa above Niagara Falls generated alternating current power with exceptionally high efficiency. When Ontario Hydro completed Beck I in 1930, it was the largest hydraulic generating station in the world. The plant continues to operate and can generate enough power to supply a small, modern city.