DVIDS – News – Hydropower: Harnessing the power of water for a sustainable future

When the gates from Sam Rayburn Lake open, water rushes into Kaplan’s turbines at a depth of about 100 feet. The river begins to rise and swell below the dam as the ground beneath your feet shakes with the force of the water flow. Fifty megawatts of electricity enter the grid to power homes near and far.

“Hydroelectric generators are unique in the quick way they can start up and produce power for the grid,” said Thomas Webb, Piney Woods Regional Hydropower Director for the U.S. Army Corps of Engineers, Fort Worth District. “A hydroelectric generator can start and produce electrical power within 5 to 10 minutes, unlike fossil fuel or nuclear power plants.”

According to the Corps of Engineers’ Hydropower Center of Excellence, hydropower is the largest renewable source of electricity, generating more than all other renewable technologies combined: 27% of all renewable electricity; 6% of total electricity and 1% of total primary energy.

Hydropower is the process of converting the energy of flowing or falling water into electricity. It is a versatile and flexible energy source that can be harnessed in different ways, including dams, river flow systems and tidal energy. The most common method is to build dams across rivers, creating reservoirs that store water. When water is released, it flows through turbines, which spin generators to produce electricity.

The Fort Worth District Corps of Engineers operates three hydroelectric power plants that can provide up to 90 megawatts of power per hour to support Texas’ power grid. This electricity is sufficient to supply energy to more than 100,000 homes.

The amount of electricity the Fort Worth area produces depends on an agreement with the Southwest Power Administration and the amount of water in each tank.

While the levees are built and maintained by the Corps of Engineers, only the Corps controls the flood basin behind the levee. Everything below this level is controlled by organizations such as the Brazos River Authority that develop and distribute water supplies, provide water and treat wastewater, monitor water quality, and pursue water conservation through public education programs.

“While they’re in the flood basin, we’re asking them to work full time,” said Timothy Helms, a hydraulic engineer training in the area. “There are different zones that limit how much we can release from each. So, in the first zone they can generate a good amount, and when you get down to the pool, we start to limit the amount they can generate for water supply purposes and drought concerns.”

One of the main advantages of hydropower is its flexibility. Many hydroelectric dams, including those in the Texas region, do not have constant water flows and are not used for primary power generation. These plants are geared toward following or peak loading operations. In addition, hydropower plants can be quickly modified to meet fluctuations in demand, making them a flexible energy source that can adapt to changing needs.

“Hydroelectric generators can also provide condensing services, which is a method in which the generator acts as a motor, and does not produce electrical energy, but rather uses electrical energy from the grid, to help stabilize voltages or system frequencies on the power grid,” Webb continued. “During emergency and unscheduled power outages, it is some hydropower generators that generally perform a ‘black start’ of the system as part of the power grid system recovery plan. This means that the hydropower generator will start and supply electrical power to the grid and provide the necessary amount of electricity To other large base load generators such as fossil fuel and nuclear power plants so they can start up and restore the power grid.

Another important advantage of hydropower is its environmental benefits. It is a clean, renewable energy source and produces no greenhouse gas emissions during operation. By replacing fossil fuel-based power plants, hydropower can significantly reduce carbon dioxide emissions and help mitigate climate change.

Furthermore, hydropower plants have a long lifespan, often exceeding 50 years, and require relatively moderate maintenance. Although moderate, it is a full-time job.

The Sam Rayburn Hydroelectric Plant was commissioned in September 1965. Even after 58 years of operation, it continues to meet the electrical demands of our communities in Southeast Texas and the regional area on a daily basis thanks to the plant’s employees, Webb said.

“At the power plant, we primarily work on the hydroelectric units, so we maintain the turbines and any ancillary equipment,” said Michael Rogers, a Corps of Engineers chief machinist for more than 10 years at the Sam Rayburn Hydropower Plant. “This includes mechanical seals, hydraulic pumps, air compressors and air systems as well as the generators themselves.”

Hydropower also provides many social and economic benefits. It creates job opportunities in construction, operation and maintenance, which contributes to strengthening local economies.

“If I could have found a job like this when I was younger, I would have really pursued it. I didn’t know jobs like this existed when I got out of high school,” said Gary Justice, a civil engineering technician at Lake Sam Rayburn. About thirty minutes from here and I started going to Mill Creek Park when I was 5 years old. Being able to work in a place I’ve always dreamed of living, just down the road, has just been a blessing for me. It’s a great job and a great place to work.”

In addition, hydropower projects can provide irrigation for agriculture, improve water supply, and control floods, benefiting communities and enhancing their ability to address climate-related challenges. According to the Water Resources Institute, hydropower is better for the environment than other major sources of electric power, which use fossil fuels. Hydropower plants do not emit heat and waste gases – common in fossil fuel-powered facilities – which mainly contribute to air pollution, global warming, and acid rain.

However, it is necessary to recognize that hydropower is not without its challenges and potential drawbacks. An MIT Climate Gateway article from 2021 states that hydropower can also cause environmental and social problems. Reservoirs radically change the landscape and the rivers on which they are built. Dams and reservoirs can reduce river flows, raise water temperatures, deteriorate water quality, and cause sediment buildup. This has negative effects on fish, birds and other wildlife.

“One might say the downside is that hydroelectric plants use water, which can change reservoir levels which can impact recreational areas and boat ramp availability, especially during dry summers and drought years,” Webb said. “The positive side of this same scenario is that during the hot and dry summer, power grids typically experience greater demand for electricity usage due to air conditioning needs and other electrical energy consumption needs. The availability of water as a constant resource to generate the required electrical energy can play an important role in ensuring Provides electric power to meet the energy needs and requirements of our local communities. There are many more positives than negatives. Hydropower is renewable, reliable, ready and relevant.

In the search for sustainable and renewable sources, hydropower has emerged as a leader in the field of green energy. By harnessing the power of water, this clean and reliable energy source has been in use for centuries, and its potential for the future is enormous. With increasing global demand for energy and the urgent need to combat climate change, hydropower provides a promising solution that can help us transition to a greener and more sustainable future.