Fajerov Mlin - Hydrology Sensors in Hydropower Plants

In a time of potential ecological disasters and climate changes, countries are trying to find sustainable solutions for transforming natural resources into energy without harming the environment. The use of renewable energy has many benefits such as reduction of greenhouse gas emissions, dependency on fossil fuels and diversification of energy supplies.

European countries, as well as other countries around the world, are developing national and international strategies to mitigate this problem by funding framework programs lines and creating strategic documents as an answer to this uprising problem.

HydropowerEurope - Project launched by European Union that is responsible for studying and promoting the use of hydropower in the Europe states that the EU is supporting the development of hydropower projects and usage of renewable energy resources to reduce the unemployment rate, to contribute to flood and drought protection, for strengthening the contribution of pumped-storage power plants by developing and building innovative arrangements in combination with existing water infrastructure, for increasing the storage of existing dams and the construction of new reservoirs and to gain more energy by optimizing the operational process to improve efficiency and environmental performance.

Daily operations of hydropower plants can be easily compromised due to harsh conditions and unpredicted factors that are complicated to measure. Turbines can suffer abrasions of suspended solids, water hammers can cause hydraulic shock that ends with cracking pipes. Overheating of machines can cause deformation of the turbines and fires. There are many other dangers that can also appear as a result of inadequate control monitoring. To keep the entire hydropower plant at the best efficiency and maximum safety for all stakeholders in the ecology chain, responsible engineers and authorized personnel need to constantly monitor relevant parameters.

To avoid worst-case scenarios and potential water ecology risks, it is necessary to implement advanced technologies with smart algorithms that are capable to mathematically calculate the statistical chances that a problem will appear. Subsequently, it is important to implement an effective safety and condition monitoring solution to ensure problems are detected in time to avoid catastrophic failures and consequential downtime. An important segment is ensuring of the hydropower plant’s operation is measuring the water level and water flow at the entrance to the hydropower plant.

The World Fish Migration Foundation has published a report in 2020 it’s stated that 93% of European freshwater migratory fish species has been lost since 1970. The growing number of dams, weirs, hydropower plants and other structures that were built for the purpose of using hydropower is one of the main reasons why there is a problem with fish pathways and the decline in the number of fish species. Various river structures have an impact on ecosystems by changing aquatic habitats, thus hindering migration. River structures can have an effect on water temperature, flow regimes, species diversity, and other ecological parameters that may have a direct or indirect effect on fish. During downstream and upstream migration, fish can swim through the hydropower turbines and can be exposed to enormous pressure changes which causes higher mortality among them. Another big problem are the turbine blades that can also hurt and kill fish. The maximum level of water reservoirs can have a big impact on aquatic wildlife. When descending over weirs, fish can also be injured by the strong currents in the stilling basin or lose their orientation, making them an easy prey for predators. It is required to create a complete monitoring-simulation solution for improving weir design for safe fish passage.

Measures to reduce dam impacts on animals include modifying dam operations to restore river flows, constructing fish passage facilities and building the fish ladders. It happens very often that smaller hydropower plants are built in such a way that they cover only part of the river flow, while the other part of the flow is intact so that the construction of the hydropower plant would not affect the fish population. In order to ensure compliance of the hydropower operation with such regulations, it is necessary to measure the total river flow, and the flow of water used to generate electricity, so that it can be checked whether a sufficient proportion of water is left to safe passage of the fish. An example of advanced management in the measurement of water resources is the small hydropower plant Fajerov Mlin. Fajerov mlin used to serve as a mill, however it suffered several big floods, and in 1995, when the concrete threshold for water intake was damaged, the plant went out of function.

As part of the solution to this problem, an advanced hydrology monitoring system is implemented to control the plant operation. Water level and flow measurements were provided by Geolux RSS-2-300WL contactless level and flow meter. There are two main reasons why operators wanted to monitor the surface velocity. The first reason is the preservation of fish species and natural habitats. Stronger water streams can harm the health of fish and destroy the natural sediments what causes poorer water quality for the whole natural environment. The second reason is a calculation of the kinetic efficiency of water energy to get data about the velocity rate of water through the turbine. This dataset is important for every hydropower facility to know if they are producing enough electricity from water, and if a flood occurs, they are able to calculate the water discharge in real-time from receiving the measuring data of surface velocity and level sensors.

This interesting case shows that Geolux products can be integrated into the most demanding environments. With expertise in hydrology and water monitoring in various surroundings, Geolux is able to provide adequate solutions that give clients added value in the area of hydrological monitoring.