# Applications of Tungsten Pseudo-Alloys in the Energy Sector
###### Abstract  
New energy generation methods are currently being discussed with a view towards the transition from traditional primary sources to more environmentally friendly options, particularly renewables. Energy storage is also closely related to this transition. Battery storage currently dominates this area. However, flywheel energy storage system technology offers an alternative that transforms stored kinetic energy into mechanical and electrical energy using a motor generator. The flywheel energy storage system technology is thus flexible and can be applied in different industrial applications. The management of the technology of recycling tungsten multi-metallic composites (W-MMC) waste material from other products and the subsequent trial production of high-strength W-MMC material with a density of more than 17,500 kg/m\({}^{3}\) from recycled powders allowed us to test the limits of the so-called \"heavy\" flywheels used in rotor production. The results achieved lead to the conclusion that the developed recycled materials of the W-MMC type with a density \(\geq\)17,500 kg/m\({}^{3}\), with a yield strength of 1200-1700 MPa depending on the production method, can be used as a substitute for the structural steels used today without an enforced reduction in the maximum allowed rotor speed due to exceeding the maximum allowed stress. tungsten pseudo-alloys; high temperature alloys; tungsten recycling; energy storage systems Article Applications of Tungsten Pseudo-Alloys in the Energy Sector  
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need. Electricity produced in this way can be used for systems operating in island-mode and grid-feeding modes. Flywheels are also an excellent complement to systems that produce energy and serve as stabilisers of the power grid. This is because the energy produced can be fed in or out depending on how much energy is needed or to satisfy the peak demand. Therefore, they are used as energy accumulation systems [3]. Other applications in which FESS technology can be applied are in railway transport through energy recovery during the braking of trains [4]; similarly, in the automotive industry, flywheels are implemented to provide additional energy to propel the vehicle by using the kinetic energy recovery system (KERS) during braking. Another possible application is aircraft carriers, where flywheels help to provide the necessary energy during aircraft take-off [5]. Another interesting solution is charging stations for electric vehicles. Wherever the electricity grid does not have the capacity to supply energy for both fast and slow car charging, charging stations based on FESS technology are a very convenient alternative. In fact, they are local energy storage devices that enable the charging of electric vehicles with double power. Thus, these are especially suitable for installation in locations where such fast charging is impossible [6]. In the context of renewable energy sources, flywheels are part of power systems in which they compensate for power failures of solar or wind power plants, especially in the case of cloudy and windless weather, when they supply the necessary energy. In this way, they replace part of the energy produced by diesel generators, which are able to provide a continuous supply of energy when needed. Diesel generators can then be switched off and turned on only to ensure the continuity of the supply [7; 8]. In general, the findings can be summarised this way: The amount of stored energy and its subsequent release depends on the choice of material from which the flywheel rotor is made. As it follows from the general equation for calculating the kinetic energy in the rotational motion of a body, the energy of the body (the rotor of the flywheel) depends on the angular velocity and the moment of inertia. If the rotational speed of the body increases, the amount of kinetic energy also increases. The kinetic energy is directly proportional to the square of the velocity.