The main objective of DeGas is to develop new technical solutions for reducing air supersaturation in hydropower facilities to levels tolerated by aquatic fauna.​

Unfortunately, there have been several incidents of gas supersaturation in Norwegian rivers that have resulted in fish dying due to “diver’s disease". This occurs when air is mixed into hydroelectric tunnels from water intakes during periods of heavy rainfall. Technical solutions are lacking to prevent gas supersaturation, and that is why this project aims to develop a technical solution that can be installed in the hydropower plant downstream the turbine.

In addition, DeGas aims to: 

  1. Design a technical solution for using ultrasound to reduce air supersaturation inside the hydropower facility. ​

  2. Design a technical solution for using turbine aeration to reduce air supersaturation inside the hydropower facility. ​

  3. Test the developed system in small and large supersaturation scale laboratory setting . ​

  4. Develop a numerical model that predicts the reductions in different types of hydropower facilities and under different saturation levels.  ​

  5. Set-up of a 2D CFD model on river hydraulics to describe the retention time of water and thereby to assist the evaluation of remaining TDG content after ultrasound exposure in the downstream river. ​

  6. Evaluate the value of the developed system by linking predicted reductions and ecological tolerance levels for supersaturation. ​