Itaipu Dam

The spillways (closed) are on the left while the generator components are on the right

The Itaipu Dam, situated on the Brazil-Paraguay border, is the world’s largest hydroelectric dam in terms of present annual energy generation. It is situated on the Paraná River, which is the 8^th longest river in the world and the 9^th most voluminous.

At the time of completion, it was the most expensive structure ever constructed and still remains the most expensive ‘thing’ on Earth, costing very roughly $30 billion in today’s money. Only the International Space Station surpasses this, costing around $100 billion.

A generator undergoes expansion in 2007

The dam’s capacity (14,000MW) is second to that of the Three Gorges Dam in China (22,500MW). Despite this, one must remember that the dam was completed in 1984 after 14 years of construction in Brazil which was under military rule at the time. It remains a truly incredible engineering achievement.

Enough concrete was used to pave a two-lane highway from Lisbon to Moscow, a distance of 4,580km (2,850 miles). Above this, the steel and iron used would allow the construction of 380 Eiffel towers.

The Itaipu Dam provides power for 90% of Paraguay (Paraguay has a population of 6,568,000 people) and 19% of Brazil (Brazil’s population is 197,000,000). This means the dam provides power to approximately 43,276,000 people. This is roughly enough for the whole population of Spain and more than enough for all of Canada’s population.

All-in-all, the dam’s spillways (used to prevent the reservoir from spilling over like a bathtub) can discharge water at 62,200 cubic metres per second. This is almost 26 times greater than Niagara Falls’ average annual flow rate (2,400 m³/s.

Aerial view of the world's most powerful hydroelectric dam