The Battle Against Ice

Operating a Pumped Storage Hydropower (PSH) plant in extreme cold requires more than just standard engineering. In countries like Norway, temperatures often drop to -40°C. Consequently, engineers must implement specific technical «tricks» to prevent the system from freezing. At asumb, we study these methods to ensure your energy asset remains reliable 24/7, even in the dead of winter.

How Norway and Arctic Nations Keep PSH Running: 5 Key Methods

1. Deep-Water Intakes (The «Warm» Bottom Strategy): Ice always forms at the surface. Therefore, Norwegian engineers place the water intake deep at the bottom of the reservoir. Specifically, water at great depths remains at a constant +4°C due to its density. This ensures that only liquid, «warm» water enters the turbines, regardless of the air temperature outside.
2. Trash Rack Heating (Electrical Resistance): The metal grids (trash racks) that catch debris are the most vulnerable to «frazil ice» (tiny ice crystals). Furthermore, these crystals can clog the grid in minutes. To prevent this, we install electrical heating elements directly inside the metal bars. This keeps the temperature just above freezing, allowing water to flow freely.
3. Subsurface Powerhouses (Caverns): In harsh climates, the powerhouse is often built deep underground inside a mountain. Clearly, the earth acts as a natural insulator. While the outside air is -40°C, the temperature inside the rock remains a steady +5°C to +10°C. This protects sensitive electronics and IEEE control systems from thermal shock.
4. Bubbler Systems (Compressed Air): To keep the area around the dam gates ice-free, engineers use «bubbler» systems. Basically, a compressor pumps air to the bottom of the gate. As a result, the rising air bubbles bring the warmer bottom water to the surface, preventing a solid ice sheet from forming and jamming the gates.
5. Oil Heating and Synthetic Lubricants: Standard industrial oils turn into «honey» at -40°C. In contrast, we use specialized synthetic lubricants and install internal heating coils in the bearing oil sumps of Gugler turbines. This ensures the turbine can start instantly without friction damage.

Real-World Examples of Arctic Excellence

• Norway (Statkraft): Norway generates 99% of its power from hydro. Their plants, like Tonstad, use deep-water circulation to keep the grid stable even during the most brutal Arctic storms. In figures, these plants maintain 100% availability throughout the winter.
• Canada (Hydro-Québec): They operate massive systems in sub-zero temperatures. By using automated de-icing protocols, they prevent ice build-up on the penstocks, ensuring that the water pressure remains constant and safe.

Conclusion: Cold is No Excuse for Downtime

A well-designed PSH plant sees winter as its most profitable season. Clearly, demand for energy is highest when it is cold. By following Norwegian standards and trusting professional engineering, you transform a harsh climate into a reliable source of power.