US 11,988,455 B2
Thermal energy storage and method for constructing such a thermal energy storage
Sven-Åke Larsson, Gothenburg (SE); Bo Bergman, Gothenburg (SE); Nils Olofsson, Gothenburg (SE); and Timo Pohjanvouri, Hovås (SE)
Assigned to Hydroc Energy Storage AB, Gothenburg (SE)
Appl. No. 18/023,641
Filed by Hydroc Energy Storage AB, Gothenburg (SE)
PCT Filed Aug. 25, 2021, PCT No. PCT/SE2021/050823
§ 371(c)(1), (2) Date Feb. 27, 2023,
PCT Pub. No. WO2022/045950, PCT Pub. Date Mar. 3, 2022.
Claims priority of application No. 2050997-2 (SE), filed on Aug. 28, 2020.
Prior Publication US 2023/0272982 A1, Aug. 31, 2023
Int. Cl. F28D 20/00 (2006.01)
CPC F28D 20/0052 (2013.01) [F28D 20/0043 (2013.01); F28D 2020/0069 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A thermal energy storage with at least one artificial thermal energy storage volume and an additional volume of rock body surrounding the storage volume, the thermal energy storage comprising:
at least one primary borehole extending from ground level to a first predetermined depth in a rock body;
at least one set of secondary boreholes located in a cluster adjacent the at least one primary borehole at ground level;
at least an upper and a lower fracture plane extending in a radial and/or oblique plane from the at least one primary borehole towards adjacent secondary boreholes, where at least one fracture plane permits a hydraulic flow between at least one of the secondary boreholes and the primary borehole;
wherein each artificial thermal energy storage volume is defined by one set of secondary boreholes and its upper and lower fracture planes;
wherein the set of secondary boreholes diverge away from the at least one primary borehole at each fractured plane level with increasing depth, without intersecting the at least one primary borehole; and
wherein the surface area of consecutive fracture planes and the storage volume of the thermal energy storage are arranged to gradually increase with increasing depth, which fracture planes are connected by the secondary boreholes.