The flywheel principle
A flywheel is a kinetic battery that stores energy into movement. The acceleration of a rotor, or spinning wheel is used to store energy as rotational energy. Electricity is transferred to the rotor via a motor-generator, which transforms electrical energy into movement- a fast-spinning wheel.
The trick of a good flywheel is to keep this wheel spinning for as long and efficient as possible. This can be achieved by keeping friction to an absolute minimum. Energy can be taken out again by decelerating the rotor, transforming movement back into electricity. Flywheels are traditionally used for delivering or storing high power peaks for short periods of time (seconds to minutes). The inherent speed and robustness of flywheels make them perfect for absorbing frequent shocks in energy systems.
Heavy or fast?
The energy stored in a flywheel can be calculated by Ek = ½ I * ω^2 . Here Ek is the energy stored as kinetic energy. ω is the angular velocity (rad/s). The I can be described as I = k * m * r2. I is the result of k, the inertia constant of the flywheel, m the mass (kg) and r the radius (m). This implies that the energy that can be stored in a flywheel is linearly related with the mass of the flywheel and quadratically depended on rim speed. This is why we go fast, not heavy. Making a small, compact flywheel that spins ultra-fast can easily match the energy stored of heavy flywheels, but can be far more efficient.
Fast-spinning flywheels need a solution for the losses that are being generated by friction of the rotor on the pin bearing. A light, compact high spinning flywheel without friction is the most advantageous way of designing flywheels since more energy can be stored in a small volume with less energy losses and more cycles.
Our solution; fast, compact, safe
The QuinteQ flywheel relies on an ultra-fast, lightweight carbon rotor that is 100 % magnetically levitated. We use carbon fiber rotors that allow us to reach speeds of 22.500 RPM. To ensure the best efficiency in the market, our design uses superconductive crystals to make our flywheel completely frictionless.
These unique magnets are also used for bullet trains and hyperloop designs. This superconductive magnetic field allows us to create the only fully magnetically levitated flywheel in the world with a passive stability bearing. This creates a high roundtrip efficiency (>98%) with the lowest stand-by energy losses in the market (<0.1% per hour). The flywheel is held in a special safety vessel that is developed by the Boeing company, making it safe and applicable for a containerized solution.