System for storing compressed gas and method for construction thereof

A method for constructing a compressed gas storage system for storing compressed gas provided by a gas compressing system, the method comprising:

• creating a borehole in ground, comprising at least a first borehole portion defined at a borehole top and having a first borehole portion depth and a first borehole portion width, and a second borehole portion defined at a borehole bottom and having a second borehole portion depth greater than said first borehole portion depth and a second borehole portion width lower than said first borehole portion width;
• providing a balloon arrangement comprising:
• an inflatable balloon in a collapsed state, said inflatable balloon having a balloon port for providing access to an inner volume of the inflatable balloon;
• an upper support member mounted on a top of said inflatable balloon, said upper support member having an upper support width greater than said second borehole portion width;
• and
• a lower support member arranged at a lower part of the inflatable balloon;
• arranging said inflatable balloon within the second borehole portion;
• providing a gas pipe assembly comprising at least one inlet gas pipe and at least one outlet gas pipe, and coupling said gas pipe assembly to the balloon port of the inflatable balloon;
• providing a drainage pipe extending into the inner volume of the inflatable balloon to a bottom of the inflatable balloon, and configured for extracting water from the inflatable balloon;
• providing at least one filling material pipe extending along the borehole to a gap defined between the inflatable balloon, said upper support member, said lower support member, and an inner surface of the second borehole portion;
• sealing said borehole in the ground with a sealing material by injecting said sealing material on a top of the upper support member to fill up an entire volume in the borehole between the upper support member and ground level, thereby anchoring said inflatable balloon to said sealing material;
• curing said sealing material as long as required to obtain a predetermined compressive strength;
• filling said inflatable balloon with water;
• providing a filling material into the gap between the inflatable balloon, said upper support member, said lower support member, and the inner surface of the second borehole portion, thereby to fully surround the inflatable balloon with filling material in a rigid and immobile state, wherein said providing of the filling material is carried out by injecting, at high pressure, the filling material, thereby to compact and consolidate the filling material around the inflatable balloon;
• releasing the water from the inflatable balloon through the drainage pipe;
• and
• filling the inflatable balloon with said compressed gas.