Large hydroelectric dams are not sustainable in developing countries

A new study indicates that many large-scale hydropower projects in Europe and the United States have been disastrous for the environment.

Dozens of these dams are removed each year, many being considered unsafe and unprofitable.

But the authors fear that the unsustainable nature of these projects has not been recognized in developing countries.

Thousands of new dams are currently planned for the rivers of Africa and Asia.

& # 39; They have all barred & # 39; – Hydropower went bad

Are there too many hydroelectric dams under construction?

Hydropower is responsible for 71% of renewable energy in the world and has played a major role in the development of many countries.

But the researchers said dam construction in Europe and the United States peaked in the 1960s and that it has been declining since then, with more dismantling than installations. Hydropower provides only about 6% of US electricity.

Dams are now being removed at a rate of more than one per week on both sides of the Atlantic.

According to the authors of this new document, the problem is that governments have been caught off guard by the prospect of cheap electricity without taking into account the total environmental and social costs of these facilities.

More than 90% of the dams built since the 1930s were more expensive than expected. They have damaged the ecology of rivers, displaced millions of people and contributed to climate change by releasing greenhouse gases from the decomposition of flooded lands and forests.

"They make a positive picture of the benefits, which are not fulfilled and the costs are ignored and passed on to the company much later," BBC News, senior author Professor Emilio Moran of Michigan told reporters. State University.

His report cites the example of two dams on the Madeira River in Brazil, which were completed just five years ago and which should only produce a fraction of the energy that they should generate due to climate change.

In developing countries, some 3,700 dams, large and small, are currently in various stages of development.

The authors state that their great concern is that many of the most important projects are causing irreparable damage to the major rivers on which they are likely to be built.

On the Congo River, the Grand Inga project is expected to produce more than a third of the total electricity currently produced in Africa.

However, the new study indicates that the main objective of the $ 80 billion facility will be to provide electricity to the industry.

"More than 90% of the energy from this project will go to South Africa for the mining sector and the people of Congo will not have this power," said Professor Moran.

"The people I study in Brazil, the power line goes over their heads and is 4,000 km from the region and no energy is provided locally."

"The big goal of rural electrification has been completely overthrown by the big interests that drive this technology and governments are ready to be convinced by them that it's the way forward."

The report points out that large facilities on these large rivers will destroy food sources, 60 million people living fishing along the Mekong River are at risk of losing more than $ 2 billion in livelihoods. The authors also believe that dams will destroy thousands of species in these hotspots of biodiversity.

In Brazil, which produces 67% of its electricity through hydropower, the reduction of water production capacity due to climate change consists in building more dams.

With the election of Jair Bolsonaro in Brazil, a temporary halt in the construction of new hydropower projects should be canceled and plans for 60 new dams are already in place.

The authors argue that given the tremendous pressure on countries to pursue renewable energy development, a mix of energy sources, including hydropower, is the most sustainable approach.

"Large hydroelectric plants do not have a future, it is our brutal conclusion," said Professor Moran.

"To conserve hydropower in the 21st century, we need to combine several sources of renewable energy," said Professor Moran.

"If so, we should invest more in solar, wind, biomass and hydropower, to the extent that we apply them to high standards, where costs and the benefits are really transparent. "

The study was published in the journal Proceedings of the National Academy of Sciences.

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