Stable and reliable operation is crucial for hydroelectric power plants—they are a key pillar in the energy mix of the future on the path to net zero. Freudenberg Sealing Technologies has taken on this task and develops application-specific seals and materials to enable sustainable and efficient energy generation from hydropower.
Depending on the climate and region, hydropower can cover more than 80 percent of a country's electricity needs. Norway leads the way with 89 percent, followed by Canada with 62 percent, Brazil with 60 percent, and Switzerland with 55 percent.
Even the smallest failures reduce efficiency, so reliable components are essential. Without the right seals, turbines and valves cannot operate smoothly. Materials from Freudenberg Sealing Technologies ensure a tight, stable connection between mechanical components. They withstand extreme conditions – from icy fresh water to fluctuating pressure conditions and salty seawater – while remaining dimensionally stable.
Hydropower plants at a glance
People have been using the energy of water for thousands of years—for example, to irrigate fields or power mills. In the past, wood or leather was used for sealing, but today, sophisticated materials are available that make the conversion of flow energy into electricity much more efficient.
Depending on the type, hydroelectric power plants place different demands on sealing technology. Run-of-river power plants and diversion power plants are installed in rivers, while pumped storage and cavern power plants serve as energy storage facilities. In addition, tidal power plants on the coasts are now reaching market maturity and harnessing the energy of the oceans. The seals used must withstand the extreme stresses of the turbines – the actual heart of hydropower.
Turbines – the key to efficiency
The height of fall, water volume, flow pressure, and angle of attack determine the choice of the appropriate turbine. A distinction is made between equal pressure and overpressure turbines:
- Constant-pressure turbines, such as the Pelton turbine, are suitable for large heads with low water volumes.
- Overpressure turbines such as Kaplan, Francis, or propeller turbines utilize pressure differences and operate efficiently under a wide range of conditions.
These four turbine types together cover around 80 percent of the global market. However, only with optimally selected sealing materials can they run reliably over the long term.
Focus on poetry
The variety of pressure distributions, flow velocities, and types of water requires in-depth expertise in material selection. This is precisely where Freudenberg Sealing Technologies' expertise comes into play. The company has built up material expertise over decades. Octavia Ohr, Head of R&D Freudenberg Xpress Customized Solutions, explains:
"It's fascinating to see how crucial these relatively small seals are for maximizing energy yield from hydropower. Each seal has its own specific shape, and not every material is suitable for every application. But I welcome every new inquiry. Working together with our materials specialists and the Freudenberg Xpress product range, we find the right material group for every environment and manufacture the required profiles to customer specifications."
