In Brazil’s third largest river basin, in the heart of the Amazon, a huge hydroelectric plant stands as a monument to the world’s oldest source of clean energy — and the great challenges it faces.
Drought and weather took their toll on the Tucuruí hydroelectric plant. Up close, visitors can see leaks that form small, unwanted waterfalls.
Also read:
Take your business to the next level with the country’s top entrepreneurs!
Completed around 40 years ago, the Tucuruí plant and hundreds of others around the world are under increasing pressure just when humanity needs much more electricity.
Droughts and prolonged periods of drought make it difficult to generate sufficient energy. Excessive rainfall also causes problems, as floods can damage equipment.
Hydroelectric production in Brazil fell 3% last year, according to Ember Energy Research. And what the country produces represents less than half of its capacity.
Continues after advertising
It may seem small, but it generates great pressure, because energy consumption is growing rapidly and hydroelectric plants historically provide more than half of the country’s electricity.
Canada, China, the United States and other countries have also faced low hydropower production in recent years. How to make up for this gap while pursuing ambitious economic and emissions targets will be the topic of the UN’s annual climate conference in Belém — a six-hour drive from Tucuruí.
Extreme weather events hit Brazil hard. In 2014 and early 2015, the country almost had to ration energy because some reservoirs were very low.
Droughts and deforestation in the Amazon — home to around 60% of the planet’s remaining tropical forests — have contributed to falling river levels.
Last year, there was so little rain that forest fires in the Amazon consumed an area the size of California. There were also floods and landslides that, occasionally, forced the closure of hydroelectric plants in southern Brazil.
“I really believe we’re past the point,” said Ivan de Souza Monteiro, CEO of Axia Energia, Brazil’s largest energy supplier and owner of the Tucuruí plant. “Climate change is here to stay.”
Continues after advertising
Monteiro’s company is investing US$270 million to modernize Tucuruí, extend its useful life and reverse part of the damage caused by time and climate conditions. Brazil is also expanding its use of wind and solar energy.
Often overshadowed by newer sources of energy, hydropower remains a gargantuan force. It is the third largest source of electricity in the world, behind only coal and natural gas.
But it is becoming less reliable. In 2023, global hydropower production fell by the equivalent of the annual consumption of Chile or the Philippines — the largest annual drop since 1965. The second largest occurred in 2021. The International Energy Agency attributes this primarily to extreme weather events.
Continues after advertising
“The fact that this is happening in so many places is alarming,” said Robert McCullough, director of Portland, Oregon-based consultancy McCullough Research. “The reality is profound and very little understood.”
Despite long-standing environmental and social challenges and concerns, some governments and energy companies advocate building more dams. China is working on the world’s biggest hydropower project in Tibet, raising warnings about water shortages in India and Bangladesh.
“As leaders around the world try to meet renewed growth in electricity consumption, I believe it is time to give hydropower the attention it deserves,” wrote Fatih Birol, executive director of the International Energy Agency, in a bulletin published in October.
Continues after advertising
Plans to adapt and seek alternatives
Tucuruí is on the banks of the Tocantins River, a four-hour drive from the nearest airport via the Transamazônica Highway.
The trip reveals two distinct portraits of the Amazon: on one side, hills covered with palm trees, fruit trees, vines and native flora; on the other, burned areas where farmers set fire to the forest to open pasture.
Continues after advertising
These fires can grow quickly. At times, fire and smoke are visible in the distance from the dam’s towering walls — a vivid reminder of the threats to Brazil’s forest, rivers and main energy source.
Axia Energia — formerly Eletrobras — sees Tucuruí as one of its most important assets and essential to supply the country, even with the expansion of solar and wind energy.
Tucuruí is the third largest electricity generator in Brazil and the eighth in the world. It can produce about 20% more energy than the largest hydroelectric plant in the United States, Grand Coulee, in Washington.
The company and the government closely monitor the health of the forest and waters behind the dam’s nearly two dozen floodgates. Teams patrol rivers by boat to ensure environmental safety and protect wildlife — including Amazonian dolphins. Up to 600 people work at the plant daily.
A five-year modernization project is underway: changing transformers, replacing five of the 25 turbines, upgrading substations and automating equipment. The goal is to make the operation more efficient and flexible as unstable weather makes production harder to predict.
“This modernization is unique,” said Allan Almeida de Lima, executive manager of operations and maintenance.
The hydroelectric plant generated 48% of Brazil’s electricity in August — its lowest level in four years. With production becoming more irregular, the country increasingly relies on solar and wind energy, which that month provided more than a third of the nation’s energy for the first time.
Resistance to dams
Hydroelectric plants are engineering marvels — not just because of their size, but because of their design. Many tower over remote and environmentally sensitive rivers.
Some countries are considering building even larger dams. China’s new mega-dam on the Yarlung Tsangpo River in Tibet is expected to become the world’s largest power plant when it begins operating in 2030 — affecting India and Bangladesh, located downstream.
Critics — especially environmental groups — have argued for decades that these projects dam rivers, threaten wildlife and flora, and accelerate deforestation.
“The environmental and social impacts of large dams have been documented for decades,” said Joshua Klemm, director of the NGO International Rivers. “There is a kind of collective amnesia about these damages.”
Xingu riverside communities still resist new dams after thousands of people were displaced by Belo Monte and Tucuruí.
Environmentalists advocate restoring existing plants rather than building new ones.
“If the dam already exists and is producing energy, use it. But don’t build more hydroelectric plants considering all the damage needed to open new areas,” said Bill Powers, engineer and energy consultant. “Brazil is the example. Village after village disappeared.”
In response, Axia said it has compensated those displaced and is working to restore affected areas.
In a statement, the company said that the construction of Tucuruí “took place with the participation of local communities, which were included in programs designed to mitigate and compensate for impacts”. It added that government agencies monitored legal compliance.
The future of hydropower
Eddie Rich, CEO of the International Hydropower Association, acknowledged that some dams have caused damage, but argued that technology is essential in the face of growing demand — including the approximately 600 million people in the world without access to electricity.
Rich said new forms of hydroelectricity can reduce impacts — such as pumped storage (pump and storage) plants, which work like batteries using reservoirs at different altitudes.
According to him, the world needs to double its hydroelectric capacity by 2050 — even though this may be impossible.
“We need to mitigate impacts on communities,” he said. “I understand the criticism. But it’s important for people to know that we have been learning and evolving over time.”
c.2025 The New York Times Company
