The Belo Monte Dam is a hydroelectric dam complex on the northern part of the Xingu River in the state of Pará, Brazil. After its completion, with the installation of its 18th turbine, in November 2019, the installed capacity of the dam complex is 11,233 megawatts (MW), which makes it the second largest hydroelectric dam complex in Brazil and the fifth largest in the world by installed capacity, behind the Three Gorges Dam, Baihetan Dam and the Xiluodu Dam in China and the Brazilian-Paraguayan Itaipu Dam. Considering the oscillations of river flow, guaranteed minimum capacity generation from the Belo Monte Dam would measure 4,571 MW, 39% of its maximum capacity.

Hydroelectricity, or hydroelectric power, is electricity generated from hydropower. Hydropower supplies one sixth of the world's electricity, almost 4,500 TWh in 2020, which is more than all other renewable sources combined and also more than nuclear power. Hydropower can provide large amounts of low-carbon electricity on demand, making it a key element for creating secure and clean electricity supply systems. A hydroelectric power station that has a dam and reservoir is a flexible source, since the amount of electricity produced can be increased or decreased in seconds or minutes in response to varying electricity demand. Once a hydroelectric complex is constructed, it produces no direct waste, and almost always emits considerably less greenhouse gas than fossil fuel-powered energy plants. However, when constructed in lowland rainforest areas, where part of the forest is inundated, substantial amounts of greenhouse gases may be emitted.