Heat storage system

A method for changing the energy distribution of a thermal reservoir, comprising:

• transferring thermal energy from at least one low-temperature section of the thermal reservoir to at least one high-temperature section of the thermal reservoir;
• wherein the transfer of thermal energy at least in part and/or at times is performed by an active thermal energy transfer means connected to an outlet at a middle portion of the thermal reservoir between the at least one low-temperature section and the at least one high-temperature section;
• and
• wherein the outlet splits into a high-temperature supply line directly supplying fluid from the outlet of the thermal reservoir to a high-temperature part of the active thermal energy transfer means, and a low-temperature supply line directly supplying fluid from the outlet of the thermal reservoir to a low-temperature part of the active thermal energy transfer means;
• wherein the low-temperature part of the at least one active thermal energy transfer means is fluidly connected to a low-temperature part return line connected to the at least one low-temperature section of the thermal reservoir and pumps fluid from the outlet of the at least one thermal reservoir to the at least one low-temperature section of the thermal reservoir;
• wherein the high-temperature part of the at least one active thermal energy transfer means is fluidly connected to a high-temperature part return line connected to the at least one high-temperature section of the thermal reservoir and pumps fluid from the outlet of the at least one thermal reservoir to the at least one high-temperature section of the thermal reservoir;
• and
• wherein the at least one active thermal energy transfer means transports heat from fluid from the low temperature supply line to fluid from the high temperature supply line so that the low-temperature part of the at least one active thermal energy transfer means pumps cooled fluid to the at least one low-temperature section of the thermal reservoir, and the high-temperature part of the at least one active thermal energy transfer means pumps heated fluid to the at least one high-temperature section of the thermal reservoir.

A thermal energy storage system comprising:

• at least one thermal reservoir;
• and
• at least one heat pump that, at least at times, transfers thermal energy from at least one low-temperature section of the thermal reservoir to at least one high-temperature section of the thermal reservoir;
• wherein the at least one thermal reservoir comprises an outlet at a middle portion of the thermal reservoir between the at least one low-temperature section and the at least one high-temperature section, the outlet of the thermal reservoir splitting into a high-temperature supply line directly supplying fluid from the outlet of the at least one thermal reservoir to a high-temperature part of the at least one heat pump, and a low-temperature supply line directly supplying fluid from the outlet of the at least one thermal reservoir to a low-temperature part of the at least one heat pump;
• wherein the low-temperature part of the at least one heat pump is fluidly connected to a low-temperature part return line connected to the at least one low-temperature section of the thermal reservoir and pumps fluid from the outlet of the at least one thermal reservoir to the at least one low-temperature section of the thermal reservoir;
• wherein the high-temperature part of the at least one heat pump is fluidly connected to a high-temperature part return line connected to the at least one high-temperature section of the thermal reservoir and pumps fluid from the outlet of the at least one thermal reservoir to the at least one high-temperature section of the thermal reservoir;
• and
• wherein the at least one active thermal energy transfer means transports heat from fluid from the low temperature supply line to fluid from the high temperature supply line so that the low-temperature part of the at least one active thermal energy transfer means pumps cooled fluid to the at least one low-temperature section of the thermal reservoir, and the high-temperature part of the at least one active thermal energy transfer means pumps heated fluid to the at least one high-temperature section of the thermal reservoir.