The powerhouse, which is part of a $440m expansion project to enhance the plant’s capacity and improve fish passage over the century-old dam, has increased the total capacity to over 230MW from about 108MW.

The new powerhouse, which is located adjacent to the existing powerhouse, which was started in 1906 and completed in 1910, will generate enough electricity to power about 100,000 homes.

The company is now looking to qualify for federal grants under the American Recovery and Reinvestment Act of 2009 that were a key factor in its decision to build the facility.

As part of the multi-year project, which created over 300 construction jobs, the company crews excavated more than 1.3 million cubic yards of rock, poured more than 71,000 cubic yards of concrete, dealt with the challenge of major tropical storms, while ensuring minimal disruption to wildlife in the area.

PPL Fossil & Hydro Generation senior vice president Victor Lopiano said the new powerhouse represents a major investment in clean, reliable, renewable energy.

"I thank everyone who was involved in design and construction of the new powerhouse. This project highlights the potential to upgrade existing hydroelectric facilities and expand capacity without the need to build new dams.

"The new facility’s two 62.5-megawatt turbines are capable of generating more electricity than the 12 existing turbines, combined," added Lopiano.