Climate resilience |
Breathing new life into hydropower
GE Vernova’s innovative aerating turbine technology enhances dissolved oxygen levels in river ecosystems while improving hydropower plant efficiency, paving the way for more flexible, sustainable energy production
OXYGEN, THOUGH INVISIBLE, is the lifeblood of aquatic ecosystems, providing sustenance for creatures ranging from the tiniest plankton to the largest fish. It maintains the delicate balance of nature, ensuring that everything from small microorganisms to large fish populations can thrive in rivers, lakes, and oceans. Without sufficient oxygen, aquatic life is put at risk, leading to shifts in biodiversity, altered ecosystems, and the degradation of natural habitats. However, ensuring adequate oxygen levels in water is not always a given. A range of factors, including rising water temperatures, increased salinity, stagnation, excess minerals like iron, and the harmful impacts of agricultural and industrial activity, can all deplete oxygen levels in rivers and lakes. To address this pressing challenge, engineers at
GE Vernova have developed a revolutionary new technology that not only restores dissolved oxygen in water but also enhances the operational efficiency of hydropower plants. By leveraging the infrastructure of hydropower dams, this advanced solution offers a dual benefit: it revitalises ecosystems while simultaneously improving energy production capacity. At the heart of this innovation is a specially designed aerating turbine equipped with “inter-blade profiles.” These are openings in the turbine’s blades that allow for more efficient air injection into the water as it flows through. This creates much smaller air bubbles than previous methods, increasing the surface area for oxygen transfer, and improving the oxygenation of the downstream water. In essence, it allows the dam to serve as a functional tool for enhancing water quality, alongside its primary role in power generation. The new turbine technology works similarly to the way air moves through the blades of a jet engine – creating suction that draws in air and generates smaller, more efficient bubbles. The result is an effective method of boosting oxygen levels without sacrificing the plant’s energy generation capabilities. This innovation addresses one of the most significant challenges faced
by hydropower plants: maintaining the required levels of dissolved oxygen to support aquatic life while also meeting the energy demands of the grid. As Kristopher Toussaint, hydraulic expert at GE
Vernova, explains: “Different biological processes eat up the oxygen that’s naturally in the water. So aquatic life requires roughly between 5 and 10 milligrams per liter (mg/l) of dissolved oxygen to thrive. Below five, it puts a stress on fish and plants, and levels closer to zero can threaten their survival.” This new aerating turbine ensures that the dissolved oxygen remains above the critical threshold of 5 mg/l, maintaining a healthier environment for aquatic organisms. The flexibility of this technology goes beyond
environmental benefits. It also allows hydropower plants to operate at much lower flow rates, increasing operational flexibility. Traditional turbines typically operate at a range of 50% to 100% load. However, hydropower plants equipped with the new aerating turbines can run effectively at much lower flow rates, optimizing energy production and providing a more responsive power source. As Toussaint explains: “It’s very complementary, in terms of asset owners’ needs.” In particular, this ability to operate at lower flow rates allows hydropower plants to better accommodate variable renewable energy sources, like solar and wind power, which can fluctuate depending on weather and time of day.
“Usually, this type of turbine will operate between about 50% and 100% load,” says Toussaint. “That’s the conventional or standard range. But more and more, asset owners are asking to operate the units over a wider range, and to have more flexibility to compensate for other variable sources of energy on the grid.” In essence, these aerating turbines transform hydropower plants into more dynamic, responsive assets capable of adapting to changing energy needs. This technology also represents a significant improvement over more traditional methods of
Right: From left: The runner, with the inter-blade profile in blue; the air path through the blade and the inter-blade profile; the air injection numerical prediction
32 | February 2025 |
www.waterpowermagazine.com
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