Energy storage systems

A thermal energy store capable of accepting, storing and releasing thermal energy at a range of more than one temperature to/from at least one thermal energy source and/or sink, said thermal energy store comprising:

• a configuration of three or more thermal energy storage banks, each of said thermal energy storage banks having an operating temperature range;
• at least one or more of the thermal energy storage banks contains thermal energy storage material comprising a single material or a mixture of materials;
• wherein said thermal energy storage material in at least one bank contains at least some of one or more types of thermal energy storage material that undergoes at least one energy absorbing and/or releasing phase transition at one or more temperatures or one or more sub-ranges of temperatures within the operating temperature ranges of each bank;
• wherein each phase transition is associated with a change in physical and/or chemical properties of said thermal energy storage material;
• and
• two or more independently controlled thermal energy transfer connections, wherein each connection comprises one or more devices for transferring heat from a lower temperature body to a higher temperature body, each connection linking two or more banks.

A method of heating and/or cooling an environment, said method comprising:

• providing a thermal energy store capable of accepting and/or storing and/or releasing thermal energy at a range of one or more temperatures to/from at least one thermal energy source and/or sink, said thermal energy store comprising:
• providing a configuration of three or more thermal energy storage banks, each of said thermal energy storage banks having a usual operating temperature range;
• providing at least one or more of the thermal energy storage banks contains thermal energy storage material comprising a single material or a mixture of materials;
• wherein said thermal energy storage material in at least one bank contains at least some of one or more types of thermal energy storage material that undergoes at least one energy absorbing and/or releasing phase transition at one or more temperatures or one or more sub-ranges of temperatures within the usual operating temperature range of each bank;
• wherein each phase transition is associated with a change in the physical and/or chemical properties of said thermal energy storage material;
• and
• two or more independently controlled thermal energy transfer connections, comprising two or more devices for transferring heat from a lower temperature body to a higher temperature body, linking two or more banks.