Lake Oroville in California: Extremely low water level
Photo: Robyn Beck / AFP
The Oroville Dam in northern California is the highest dam in the United States even before the Hoover Dam and, at 235 meters, is one of the largest dams in the world.
In good years, the power of the thawed water of the Feather River generates enough electricity to supply half a million households with electricity.
The six turbines of the 750-megawatt hydropower plant have been idle for a few days - for the first time since its construction in 1967. The water level in the lake has fallen below the minimum required to generate electricity. Houseboats are partly on dry land, large areas of water have simply disappeared. The high temperatures and persistent droughts in California had significantly reduced the water runoff into the reservoir this spring. "I've lived in California all my life and have never seen the water level this low," a resident of the lake told a local broadcaster.
The Oroville Dam is not the only one whose electricity production no longer works smoothly. The power plants on Lake Shasta, the largest reservoir of the government's Central Valley Project in California, generated around 30 percent less electricity than usual this summer. And the well-known Hoover Dam on the Colorado River on the border between Nevada and Arizona also produced about 25 percent less last month, according to the responsible authority.
In Brazil or China, where hydropower contributes significantly more to electricity generation, operators have to accept losses in electricity generation due to droughts, little precipitation and low water levels in reservoirs. And so the climate crisis, as a cause, means that emission-free hydropower, of all things, does not generate enough energy. As a result, some countries will have to make greater use of fossil fuels. According to scientists and energy experts, nations with a relatively high proportion of energy from hydropower face a long-term problem. According to the International Energy Agency (IEA), hydropower is the world's most important source of clean energy, accounting for nearly 16 percent of global electricity generation.
In California, Governor Gavin Newsom issued an ordinance on July 30th, due to the reduced amount of electricity from hydropower, that allowed the industry to use diesel generators and engines, which emit more greenhouse gases.
Ships in ports were also allowed to use diesel generators - a move that environmentalists criticized because it would degrade California's air quality and undermine the state's efforts to combat climate change.
However, too much water, as can occur from floods and heavy rain caused by climate change, is also a problem.
In 2020, for example, two power plants in Malawi had to be shut down due to flooding, reducing hydropower capacity from 320 megawatts (MW) to 50, according to the IEA.
Unfortunately, if hydropower fails, it is often replaced by fossil fuels that release greenhouse gases that are harmful to the climate, according to climate resilience researcher Kristen Averyt from the University of Nevada in Las Vegas.
Brazil, where hydropower is the most important source of electricity with 61 percent, is trying to compensate for the decline with power plants that are mainly operated with natural gas.
Many environmentalists see the construction of hydropower plants, for example in Europe, as a whole as critical, as a lot of nature is often destroyed for little income.
joe / Reuters