Marmelos Zero Power Plant, Decommissioned hydroelectric power station in Juiz de Fora, Brazil

Marmelos Zero Power Plant is a decommissioned hydroelectric power station on the Paraibuna River in Juiz de Fora, Brazil. It consists of the original plant building, a dam, and a canal that diverted water to the generators, and now operates as a museum.

Built in the late 1880s, it was the first major hydroelectric plant in South America and began producing power in 1889. After decades of service, it was bought by CEMIG in 1980 and later turned into a museum.

The name Marmelos comes from the marmelo fruit trees that once grew along the riverbanks. Today, the old plant is a meeting point for school groups and families who come to learn about the city's early steps into the electric age.

The site is easy to explore on foot, with paths around the old building and the dam. Visitors should wear comfortable shoes and allow time to walk along the riverbank and read the information panels.

The original dam, about 167 feet (51 meters) long, still diverts water to two downstream plants that continue to generate power. Visitors can see the old machinery that once lit the city's first light bulbs.