The estate's powerhouse was the first of more than 20 hydroelectric plants built by Henry Ford. Two direct current hydroelectric generators converted the force of the Rouge River into electrical energy to power light bulbs, pumps, and other mechanical systems throughout the estate. Thomas Edison, an early mentor and lifelong friend of Henry Ford, laid the cornerstone of the powerhouse on October 28, 1914. The powerhouse helped make Fair Lane self-sufficient and once provided electricity to run machinery at the nearby Water Works facility on Michigan Avenue that supplied water to the surrounding area. At the time of its construction, this state-of-the-art plant set new standards of efficiency. The technology was later used to adapt historic water mills and build additional plants throughout southeastern Michigan. The design allowed river water to enter through three underground headraces, where it was filtered by trash racks, then spin one of two turbines connected by shafts to twin 55-kilowatt generators on the top floor before flowing back to the river through the tailrace.