Abstract: Heat buffer comprising at least mechanically coupled wall parts, wherein each of the wall parts comprises a substantially plate-like body; a liquid throughflow circuit incorporated in the body; one or more hydraulic couplings accessible from the outer side of the wall part for discharge and supply of liquid to the liquid throughflow circuit and configured for coupling to hydraulic couplings of a similar device; and is coupled at a mutual angle about a substantially vertical axis to a similar wall part, wherein the mechanically coupled devices are connected such that they enclose one space and wherein the heat buffer also comprises a floor and/or cover part for closing the enclosed space on an upper and/or underside.

Abstract: Underground thermal energy storage in a cylindrical or n-gonal prism shape with a vertical axis, comprising an inner volume for holding a liquid, an outer wall, an inner wall around the inner volume, and a filling layer between the inner wall and the outer wall. The inner wall comprises a series of modular wall parts provided with a heat exchanger for exchanging thermal energy with the liquid. The modular wall parts, arranged in rings, contact the inner volume and have an elastic sealing limiting liquid flow between the inner volume and the filling layer and taking up thermal expansion of the modular wall parts. The filling layer comprises an insulating layer designed to keep the outer wall below 30° C. when the inner volume is at least 90° C., and a structural layer for maintaining the insulating layer and the inner wall's modular wall parts in position.

Abstract: Underground thermal energy storage in a cylindrical or n-gonal prism shape with a vertical axis, comprising an inner volume for holding a liquid, an outer wall, an inner wall around the inner volume, and a filling layer between the inner wall and the outer wall. The inner wall comprises a series of modular wall parts provided with a heat exchanger for exchanging thermal energy with the liquid. The modular wall parts, arranged in rings, contact the inner volume and have an elastic sealing limiting liquid flow between the inner volume and the filling layer and taking up thermal expansion of the modular wall parts. The filling layer comprises an insulating layer designed to keep the outer wall below 30° C. when the inner volume is at least 90° C., and a structural layer for maintaining the insulating layer and the inner wall's modular wall parts in position.

Abstract: Heat buffer comprising at least mechanically coupled wall parts, wherein each of the wall parts comprises a substantially plate-like body; a liquid throughflow circuit incorporated in the body; one or more hydraulic couplings accessible from the outer side of the wall part for discharge and supply of liquid to the liquid throughflow circuit and configured for coupling to hydraulic couplings of a similar device; and is coupled at a mutual angle about a substantially vertical axis to a similar wall part, wherein the mechanically coupled devices are connected such that they enclose one space and wherein the heat buffer also comprises a floor and/or cover part for closing the enclosed space on an upper and/or underside.

Abstract: Heat buffer comprising at least mechanically coupled wall parts, wherein each of the wall parts comprises a substantially plate-like body; a liquid throughflow circuit incorporated in the body; one or more hydraulic couplings accessible from the outer side of the wall part for discharge and supply of liquid to the liquid throughflow circuit and configured for coupling to hydraulic couplings of a similar device; and is coupled at a mutual angle about a substantially vertical axis to a similar wall part, wherein the mechanically coupled devices are connected such that they enclose one space and wherein the heat buffer also comprises a floor and/or cover part for closing the enclosed space on an upper and/or underside.

Abstract: The invention provides an underground thermal energy storage having a shape selected from substantially cylindrical and an n-gonal prism, having an axial direction that in use is vertical, and comprising an inner volume for holding a liquid, said energy storage device comprising a peripheral outer wall, a peripheral inner wall around said inner volume, and a filling layer between said inner wall and said outer wall, said inner wall comprising a series of modular wall parts provided with a heat exchanger for exchanging thermal energy with said liquid, said modular wall parts arranged in rings and said modular wall parts each having opposite radial surfaces that are in use vertical, an inner tangential surface contacting said inner volume, an outer tangential surface directed towards said outer wall, and opposite axial surfaces that are in use horizontal, said modular wall parts comprising an elastic sealing between a joint of adjacent radial surfaces for limiting liquid flow between the inner volume and the fi