The original Rheinfelden plant was an outstanding achievement in Europe's early large-scale hydroelectric power generation, with a 17,000 horsepower (12,500 kW) output. It pioneered the use of three-phase alternating current — later adopted worldwide — and the use of a 50-hertz frequency, which afterward became standard in most countries. Rheinfelden gradually entered joint operation with other stations, giving rise to the interconnected power network of continental Europe.