A Process to Make a Hybrid Flywheel-Buoyancy Energy Storage System

Abstract

This paper presents a conceptual hybrid energy storage and recovery process that combines flywheel energy storage, liquid redistribution under centrifugal effects, and buoyancy-assisted energy extraction within a single cyclic system. The proposed arrangement consists of a liquid-filled multi-arm flywheel, a buoyant member positioned along the axis of rotation, and controllable valve–turbine mechanisms located between interconnected chambers. During operation, external energy is supplied to rotate the flywheel, causing the liquid to redistribute radially outward under centrifugal action. This redistribution creates a liquid-deficient region near the axis while simultaneously increasing the gravitational potential energy of the displaced liquid. A buoy is then positioned and locked within the central region. After extraction of the flywheel’s rotational kinetic energy, the stored liquid is allowed to flow back through turbine mechanisms, enabling recovery of energy associated with the elevated liquid configuration. Subsequently, the buoy is released, and its upward motion under buoyancy is utilized for additional energy extraction. The process concludes with a secondary liquid redistribution stage that restores the system to its initial configuration, thereby completing a repeatable operating cycle. The concept seeks to integrate rotational, hydraulic, and buoyancy-based mechanisms into a unified energy storage architecture. The presented figures illustrate the sequential operational stages of the proposed system and provide a framework for further theoretical and experimental investigation.

Introduction

This paper proposes a hybrid energy storage and recovery system that combines flywheel energy storage with buoyancy-based energy conversion to improve the efficiency and versatility of mechanical energy storage. Conventional storage technologies such as batteries, pumped hydroelectric systems, compressed air storage, and traditional flywheels face limitations in terms of efficiency, scalability, or energy losses. The proposed system seeks to overcome these challenges by integrating rotational motion, liquid redistribution, and buoyancy into a single cyclic process.

The system consists of a hollow flywheel filled with liquid, a buoyant body (buoy), and valve-cum-turbine mechanisms. When the flywheel is rotated, centrifugal force causes the liquid to move from the central region into the outer arms, creating an empty space along the axis of rotation. The buoy is then lowered into this liquid-free central region and locked in place while the redistributed liquid stores potential energy due to its elevated position.

After the flywheel's rotational kinetic energy is extracted, the flywheel comes to rest, but the liquid remains temporarily locked in the outer arms. Releasing the valves allows the liquid to flow back toward the central chamber through turbines, converting the stored gravitational potential energy into electrical or mechanical energy. Once the liquid levels equalize, the buoy lock is released, allowing the buoy to rise due to buoyancy. The upward movement of the buoy provides another source of recoverable energy. As the buoy reaches the surface and is returned to its initial position, additional liquid flow occurs, enabling further energy extraction. Finally, the system returns to its original state, completing one full energy storage and recovery cycle.

The paper illustrates the complete operation through six schematic figures showing the successive stages of the process, including the initial state, liquid redistribution during rotation, energy recovery from liquid flow, buoyancy-driven motion, and restoration of the initial configuration. Valve-cum-turbine mechanisms alternately function as valves to control liquid movement and as turbines to generate power during fluid flow.

Conclusion

The output harnessed energy from such a flywheel obeying the described process can be considered as the sum of the harnessed rotational kinetic energy of the flywheel, the harness of the raised potential energy of the liquid due to the redistributed position of the liquid by capturing the energy from the flow of the liquids when released from left and right arms towards the central arm of the flywheel, and the harness of the energy from the motion of the buoy under the influence of buoyancy. It must be stated that the figures here are conceptual/schematic in nature and are only meant for the explanation of the concept of the process and the described process can be applied in many different structural configurations of the flywheel. The described process ignores all the frictional, turbulent and viscous losses, & considers mass of the buoy negligible and the volume of the valve cum turbine mechanisms negligible.

References

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Copyright

Copyright © 2026 Saumya Deep. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.