An energy storage device comprising a large scale flywheel supported by a fluid bearing. The energy storage device is a very large scale structure having a flywheel of a diameter greater than 100 feet and a concrete steel reinforced rim weighing in excess of 1000 metric tons. In off peak periods the apparatus is operated as a motor with energy input causing the rim to rotate up to a predetermined speed and to maintain rotation at that speed in the power take off mode during peak power time periods, the operation of the electrical circuitry is reversed and the flywheel generates electrical energy which is delivered by the storage device to the power grid. As energy is delivered the rotational speed of the flywheel diminishes and gravitational waves capable of being shaped and modulated are generated. Likewise as energy is added to the device the rotational speed of the flywheel increases and again gravitational waves capable of being shaped and modulated are generated. Such gravitational waves can be utilized for communication, propulsion and for the purpose of testing new physical theories, concepts, and conjectures. A unique electrical circuit utilizing coils and power transistors under computer software control facilitates the functioning of the apparatus as a peak power energy storage device, as an energy supply device obtaining energy directly from the wind or as a gravitational-wave generating device.