The device comprises an air compression unit,an air expansion unit, an air storage chamber, a weight and a generator; the inlet of the air compression unit is connected with an air inlet device, the outlet of the air compression unit is connected with the inlet of the air storage chamber through an energy storage pipeline, the outlet of the air storage chamber is connected with the inlet of the air expansion unit through an energy release pipeline, and the outlet of the air expansion unit is connected with the generator; a heat exchange unit is arranged between the energy storage pipeline and the energy release pipeline; the weight is arranged on the upper part of the air storage chamber and forms a piston -cylinder system with the air storage chamber; and a sealing device is arranged between the weight and the air storage chamber.
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Among all energy storage systems, pumped hydro energy storage and compressed air are mature and large scale commercialized technologies. Combining the working principles of these two systems, a new concept is proposed in this paper, known as, compressed air gravity energy storage system.
Does compressed air gravity storage improve system storage capacity?
The obtained results demonstrate that the use of compressed air significantly improves the system storage capacity. Therefore, compressed air gravity storage could be considered an attractive solution to the integration of large-scale intermittent renewable energy.
To overcome the aforementioned issue faced by pumped hydro storage, a novel system, named gravity energy storage, is under development. Toward the improvement of this latter system, this paper proposes the combination of gravity energy storage with compressed air.
What is the potential storage capacity of compressed air gravity energy storage?
Good prospects have been shown for the potential storage capacity of compressed air gravity energy storage. An interesting amount of 32.5 MWh could be stored in this system rather than 20 MWh which represents the actual capacity of gravity storage without the inclusion of compressed air. Fig. 6. Energy released according to air-water ratio. Fig. 7.
The energy production of this technology has been compared to that of gravity energy storage without the incorporation of compressed air. The obtained results demonstrate that the use of compressed air significantly improves the system storage capacity.
Do compressed air pressure and high weight tower piston affect stored energy?
The combined influence of compressed air pressure and high of weight tower piston on the stored energy will be analysed. The obtained results allow the optimal design of such a combined power tower storage system. When the compressed air or high weight piston is missing on obtain GHPTS or CAPTS respectively.