The significant number of activities were carried out towards achieving the project's objectives within the entire project period of HydroFlex being within the framework of Grant Agreement.
HydroFlex has used several hydropower plants as cases in the project. Stornorrfors (Sweden) and Bratsberg (Norway) power plants were particularly useful in the work on flow scenario modelling, mitigation technology and social acceptance while Porjus (Sweden) power plant was used for the demonstration of the generator technology. The development of the technology had included the development of turbine, generator, and converter for highly flexible operation. In addition, the technology for mitigation of rapid variations of the flow in the river downstream the power plant was being developed. The turbine development resulted in new design tools for Francis turbines. The tool was verified by a model test of a Francis turbine in the Waterpower Laboratory at NTNU. The generator development resulted in new rotor concept for low loss variable speed operation and improved torque control through current controlled magnetization system. This was tested in the laboratory at Uppsala University and there were discussions on how to implement this at Porjus power plant. The work on the environmental impact from flexible operation of hydropower plants was focusing on the impact on the fish living in this area, the recreational usage of the river and how to mitigate these effects. A unique mitigation technology was implemented, which dampen the rapid variations of the flow in the river downstream the hydropower plant. The work on social acceptance included interviews with a diverse range of stakeholder groups. Those groups comprised activities related to water and rivers like anglers, water sport activities, hiking and walking. Interviews were also performed with representatives from the producer side and included indigenous people (Sami people) and their use of rivers for transportation in general and under migration between summer and winter pastures. Dissemination, communication and exploitation activities was challenged due to the Covid 19 situation. However, we managed to have online training seminars for young researchers and 4 digital workshops/events including an EU Green Week event. Eight newsletters were issued and distributed as planned, out of which, four newsletter were prepared in collaboration with the AFC4Hydro (Horizon2020 project).
Main HydroFlex results achieved during the entire project period are:
- Completion of a guide which provides extensive analysis and model description on the market analysis and frequency stability analysis of Scandinavian hydro-power plants.
- Further development and refinement of a parametric design tool for flexible hydraulic turbines.
- Development of a controller for a variable speed hydropower plant, to enable fast frequency support provision.
- Input of hydraulic and ecological modelling to ACUR (Air Cushion Underground Reservoir) technology in Nidelva (Norway).
- Coupling of hydraulic modelling to knowledge of fish migration in Ume alv (Sweden) which was further used in assessing the public acceptance of increased ramping rates.
- Dissemination of the project through eight newsletters .
- Organization of four public webinars and EU Green Week partner event entitled “European hydropower is important for the Green Deal”.
- Organization of four public workshops.
- Publication of 29 peer- reviewed articles and journals and four more are in the process of being published.
