Hydropower Is Bad Bargain, Claims Indian Expert
The age of cheap oil and gas has come to an end. Russia's conflict in Ukraine is raising global energy costs and creating the prospect of a worldwide energy crisis. Alternative energy sources are becoming more tempting by the day, as they should.
Photo Insert: Hydropower is the most frequently used renewable energy source today, accounting for about half of all low-carbon electricity generation worldwide.
But, as Brahma Chellaney, a professor of Strategic Studies at the New Delhi-based Center for Policy Research, observed in a June 30, 2022 piece for Project Syndicate, the embrace of hydropower, in particular, bears its own risks.
Hydropower is the most frequently used renewable energy source today, accounting for about half of all low-carbon electricity generation worldwide.
Several things contribute to its popularity. It was the most cost-competitive renewable for decades, and many hydropower plants can expand or reduce electricity generation far faster than nuclear, coal, and natural-gas plants.
And, unlike wind and solar, hydropower can be reliably produced using reservoirs, making it a useful complement to these more variable sources, according to Chellaney, who is also a fellow at the Robert Bosch Academy in Berlin.
But there is a hitch. The damming of rivers and streams is the most prevalent type of hydroelectric facility. And hydroelectric dams have a significant and long-term ecological impact.
To begin with, while hydroelectric energy produces no greenhouse gases, dams and reservoirs produce considerable volumes of methane, carbon dioxide, and nitrous oxide. In some cases, such as in tropical areas, they can emit more greenhouse gases than fossil-fuel power plants.
According to one study, methane - a greenhouse gas at least 34 times more potent than CO2 - can account for up to 80% of emissions from artificial reservoirs, albeit reservoir emissions are affected by a range of geographical, climatic, seasonal, and vegetational factors.
Furthermore, while hydroelectric dams are frequently praised for providing clean drinking water, managing floods, and assisting with irrigation, they also alter river temperatures and water quality and obstruct the passage of nutrient-rich sediments.
Such sediments are critical for re-fertilizing degraded soils on downstream plains, preventing river channel erosion, and preserving biodiversity. Deltas shrink and sink when dams trap silt pouring in from the mountains.
This causes salt water to infiltrate inland, disrupting the delicate balance of fresh and salt water required for the survival of key species in coastal estuaries and lagoons. It also makes deltas vulnerable to the full force of storms and hurricanes.
In Asia, heavily populated deltas – home to megacities like Tianjin, Shanghai, Guangzhou, Bangkok, and Dhaka – are already retreating fast.