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.
Turbine technology
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 increasing oxygen levels in water. Many dams simply spill excess water in an attempt to raise oxygen levels, a method that can result in wasteful energy production and doesn’t achieve the optimal oxygenation levels needed for a healthy ecosystem. The new aerating turbines are far more efficient, as they inject oxygen into the water through the turbine itself, using the natural flow of water to disperse tiny air bubbles throughout the downstream ecosystem. This method not only preserves energy but also ensures more precise oxygenation levels.
“I think the real strength of our technology is the physical implementation of an additional profile inside the turbine, which allows us to generate suction, to draw in more air than what other manufacturers can achieve, and at the same time provide additional structural rigidity,” says Toussaint, underscoring the unique design of this solution.
Hydropower plays a vital role in the global energy landscape, generating approximately 15% of the world’s electricity. In many regions, hydropower is also seen as a key component in the transition to a low-carbon energy future. However, as many of the world’s hydropower plants age, there is a need for modernisation to ensure these facilities remain efficient, effective, and environmentally responsible. The new aerating turbines from GE Vernova offer a practical solution for this issue. By improving the oxygenation process, these turbines not only enhance the environmental performance of hydropower plants but also extend the operational lifespan of aging infrastructure.
“These refurbishments are expected to help these units remain viable for another 50 years,” says Toussaint. This is particularly important, as many hydropower plants have been in operation for decades. Modernisation efforts like these ensure that these plants can continue to contribute to energy production while also meeting the environmental and regulatory requirements necessary to protect aquatic life and water quality.
GE Vernova and Dominion Energy: a partnership for the future
One prominent example of the real-world application of this technology is the ongoing modernisation project at the Saluda Hydro power plant in South Carolina. The Saluda Hydro plant, which has been operational since 1930, provides a perfect case study for the benefits of this new technology. Located on the Saluda River near Columbia, South Carolina, the plant has been serving the region for almost a century, providing reliable, low-carbon energy to the surrounding communities.
In 2024, GE Vernova secured an order from Dominion Energy South Carolina for the modernisation of two hydropower units at the Saluda Hydro plant. This project will include the installation of the advanced aerating turbine technology to replace the existing turbines in Units 1 and 3, and the rehabilitation of the Unit 3 generator. The goal is to increase dissolved oxygen levels in the river, improving water quality and supporting the river’s aquatic ecosystem. Additionally, this modernisation will extend the plant’s operational lifespan and improve its energy production efficiency.
“Investing in their replacement will help maintain the facility’s long-term reliability and, most importantly, continue to safely serve our customers for many years to come,” said Iris Griffin, Vice President of Generation at Dominion Energy. The integration of GE Vernova’s aerating turbines ensures that the Saluda Hydro plant will remain a valuable asset for the community, not just for energy production, but for the health of the surrounding environment as well.
Frederic Ribieras, CEO of Hydro Power at GE Vernova, emphasised the importance of this collaboration, stating: “Our team is delighted to bring its advanced solution to a site that has been serving the state for almost a century. This project shows that through both electricity generation and water management, hydropower can provide many benefits to communities, for a very long time.”
A lasting legacy for the future
As hydropower continues to provide a significant portion of the world’s renewable energy, innovations like GE Vernova’s aerating turbines are helping ensure that this important energy source remains viable and effective for decades to come. This new technology not only offers a solution for enhancing water quality but also contributes to making hydropower plants more adaptable to the evolving needs of modern energy grids. With its ability to generate power flexibly while maintaining healthy ecosystems, GE Vernova’s aerating turbine technology represents a significant leap forward in hydropower innovation.
Hydropower continues to play a crucial role in the global transition to cleaner energy. In the United States, hydropower accounts for nearly 27% of the total renewable electricity generation and almost 6% of the nation’s overall electricity supply. The modernisation of aging plants through innovations like the aerating turbine technology will enable hydropower to remain a cornerstone of the renewable energy mix, helping meet the growing demand for clean energy while also supporting ecosystem health.
“As one of the oldest sources of renewable energy in the country, the ~100GW installed base is aging, and we see large opportunities for modernisation projects to enable them to deliver even more renewable energy into the grid and help accelerate the energy transition in the country,” noted Ribieras.
By embracing new technology, the hydropower industry is ensuring that it can continue to serve as a reliable, low-carbon energy source for generations to come, while also helping to safeguard the natural environments that depend on it.
