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Increasing the value of Hydropower through increased Flexibilty

Periodic Reporting for period 3 - HydroFlex (Increasing the value of Hydropower through increased Flexibilty)

Reporting period: 2021-05-01 to 2022-04-30

HydroFlex – Increasing the value of Hydropower through increased Flexibility – is a €5,7m H2020 research and innovation action. The project aims towards scientific and technological breakthroughs to enable hydropower to operate with very high flexibility.

HydroFlex aims to develop new technology permitting highly flexible operation of hydropower stations. Flexibility of operation here means large ramping rates, frequent start-stops and possibilities to provide a large range of system services. All this within (strict) excellent environmental and social conditions while being economically competitive compared to alternative solutions. The project will perform research and innovation activities on key bottlenecks of hydropower units that restrict their operating range and thus limit their flexibility. Thereby, HydroFlex will create the technical, environmental and social basis for successful future industrial developments.

The specific objectives are:
- Identify and describe the demands that hydropower plants will be confronted with in future power systems;
- Develop a variable speed Francis turbine that accommodates high ramping rates and 30 start-stop cycles per day;
- Develop new power station electrical layouts, generator rotor and magnetization systems, and power electronic converter control for increased flexibility and strong grid support;
- Assess social acceptance and test innovative methods to mitigate social and environmental impacts;
- Carry out effective dissemination, communication and exploitation activities to promote the research results to the relevant stakeholders.
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.
HydroFlex develops technology that enables manufacturers to deliver turbines, generators and converters that can handle the fatigue loads, which will be present in the future operation of hydropower plants. More specifically, HydroFlex technology focuses to handle 30 start-stop cycles per day. This ambitious objective pushes hydraulic turbines, electrical equipment, mitigation of highly fluctuating discharges and the knowledge about environmental and social impacts of highly flexible operation beyond the state of the art.

These advancements in hydropower research and innovation will enhance the flexibility of hydropower and thereby contribute to securing system stability at the European level. The reliability of the transmission system will increase and the balancing of the intermittency of electricity produced by VRES improve. Hence, the risks associated with the integration of VRES will be reduced.

The expected improvements of the turbine design and the adoption of new generator and converter concepts will improve operation and increase lifetime of hydropower plants. Manufacturers adopting the project results will be able to design new hydropower systems and components with the ability to handle a larger number of start-stop cycles compared to the existing equipment. This will nurture the development of industrial capacity and strengthen the European industrial technology base.

HydroFlex research on environmental and social impacts and mitigation methods will contribute to reduce the life-cycle environmental impact and improve the socio-economic evaluation the decision-makers face. The project aims to identify win-win solutions, allowing for both increased hydropower flexibility and sustainable livelihood of local communities along the watershed. These win-win solutions will also reduce costs related to show-stoppers late in the process due to public resistance.

Last, but not the least, HydroFlex has contributed to enabling hydropower to become a major contributor to the clean energy transition, and hence to the major effort needed to meet the commitments of the Paris Agreement and mitigate global climate change.
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