Brazil's mega dams were supposed to lead the way for a greener future. Climate change came next

Amazon megadams operating at capacity well below their maximum as river levels are low

The drought has exacerbated the problem of underperformance.

Brazil switches to natural gas, a polluting fossil fuel

By Andre Cabette Fabio

When he first came to power in the early 2000s, Brazil's President Luiz inacio Lula da silva bet his green future on "run-of river" megadams - whose turbines move by natural river flow rather than cascading water from towering dams.

Santo Antonio Jirau and Belo Monte have been built in the Amazonian rainforest despite the strong opposition of environmental groups. They are now among the five most powerful dams within the country. Belo Monte was built in 2016 and has the fourth largest capacity in the entire world.

The megadams are operating well below their capacity due to the record drought in Amazon. This highlights how climate change has become a major challenge for Brazil's green goals.

A guide who showed tourists the Santo Antonio Dam earlier this year said, "Unlike old power plants the river is in charge, and if it becomes too dry, it will stop working."

Santo Antonio was forced to shut down 43 of its 50 turbines in early September due to a drought that caused river levels to reach a record low. In October 2023, the same reason led to a two-week shutdown.

Three megadams only worked at a fraction of capacity in September. This is a continuation of a trend in which hydropower companies consistently fail to meet their "minimum guaranteed energy" output as set forth in their contracts with government.

According to data from the government, Santo Antonio worked at less that 10% of its potential in the first twenty days of September. Jirau was at 5% and Belo Monte, at less than 3 %. Santo Antonio, Jirau, and Belo Monte worked at double their capacity during the same period in 2021. That was a year when Brazil's Amazon suffered from heavy rain.

Experts predict that the situation will worsen as future droughts become more frequent.

According to a 2015 report, commissioned by Brazil's government, the energy potential of natural river flows will decline between 7 and 30 percent by 2030.

History of Underperformance

Hydropower makes up 47% of Brazil’s energy capacity. Lula's goal is to make Brazil a net energy exporter or, as he called it, "the Saudi Arabia of renewable energies in 10 years". Saudi Arabia is currently the largest crude oil exporter in the world.

Lula's wager on "run of river" dams was to secure cheap energy with less environmental impact than traditional dams which create large reservoirs.

Experts say that the performance of Amazon's megadams has been subpar for some time, and this calls into question the green strategy of the government.

According to historical river flow patterns, the "minimum guaranteed energy" is the amount of electricity that power plants are committed to deliver to national electricity systems.

Celio Bernmann, professor of the Institute for Energy and the Environment at the Universidade de Sao Paulo, says that the past is not a good indicator for future river levels because the climate is changing.

Hydropower companies, as river levels drop, are forced to purchase electricity on the spot market from other producers, at a high cost to them, in order to meet their contractual obligations.

Mario Daher, an energy consultant, said that if water levels don't rise in the next few years, "those Amazon power plants" will be bankrupt.

According to the Brazilian Electricity Regulatory Agency, Jirau's minimum assured energy output is 2.1 Gigawatts and Belo Monte’s is 4,41 Gigawatts.

ALTERNATIVES?

The Amazon megadams' electricity output has decreased, so the authorities have resorted to expensive and polluting fossil fuels.

Arayara International Institute, a non-profit organization, says that the government is building 15 new gas-powered plants. This should increase Brazil's capacity to generate natural gas by at least 30% and therefore increase carbon emissions.

A report published in August by the Institute for Energy and the Environment, a non-profit organization, proposes the use of solar and wind power to convert smaller hydropower plants into "pumped-storage hydropower plants".

When the sun is down and the winds ease, the idea is to fill reservoirs with water that can be used later to generate electricity.

According to the Energy Research Office of Brazil, solar and wind power has grown rapidly in Brazil over the last five years and now represents 29,4% of its energy capacity.

Vinicius Oliveira Da Silva, a researcher at the Institute for Energy and the Environment, a non-profit organization, says that the output of Santo Antonio Jirau and Belo Monte can also be increased by building additional dams along the rivers as originally planned.

This would be controversial, given the opposition against the original dams as well as their poor track record.

Environmentalists claim that their construction contributed to the deforestation of forests, loss of biodiversity, and displacement of tens thousands of Brazilians.

What good was it to kill the river... the forest...and the animals? Ana Barbosa is the coordinator of the Xingu vivo movement which opposes Belo Monte dams and other dams on the Xingu River.

"You have a monument on the bank of the river, so that men can claim they built it even though the result is nothing but disaster and blood."

Lula's government, after he came back to power in 2023, has re-started the talks with Bolivia about building a new megadam in the Madeira River, which is on the border of the two countries.

Oliveira da Silva said that this would be a win for his government, as it would boost production at Jirau, and Santo Antonio on the Madeira River, but the environmental impact would be greater in Bolivia.

(source: Reuters)