Thermal energy storage devices, systems, and thermal energy storage device monitoring methods

1. A system comprising:

a thermocline location system configured to monitor a plurality of locations of a thermocline within a thermal energy storage medium of a thermal energy storage device at a plurality of different moments in time;

circuitry coupled with the thermocline location system and configured to provide information regarding the locations of the thermocline within the thermal energy storage medium of the thermal energy storage device at the different moments in time using the monitoring of the locations of the thermocline;

wherein the thermocline location system comprises: a position indicating object configured to move throughout different locations of a reservoir of the thermal energy storage device which holds the thermal energy storage medium as a result of changes in the locations of the thermocline within the thermal energy storage medium; and a monitoring device configured to monitor the locations of the object; and

wherein the circuitry is configured to use the monitored locations of the object to provide the information regarding the locations of the thermocline within the thermal energy storage medium.

2. The system of claim 1 wherein the monitoring device is configured to emit a first signal towards the object, to receive a second signal resulting from a reflection of the first signal from the object, and to monitor the locations of the object using the second signal.

3. The system of claim 1 wherein the thermal energy storage medium is a liquid and the locations of the thermocline are below an uppermost surface of the liquid.

4. The system of claim 1 wherein the monitoring device is an initial monitoring device, and wherein the thermocline location system comprises an additional monitoring device, and the initial monitoring device and the additional monitoring device are positioned at different elevations of the thermal energy storage device.

5. The system of claim 1 wherein the circuitry is configured to use the information regarding the locations of the thermocline to provide information regarding an energy state of the thermal energy storage device at the different moments in time.

6. The system of claim 5 wherein the circuitry is configured to provide the information regarding the energy state of the thermal energy storage device as representations of amounts of energy stored in the thermal energy storage medium at the different moments in time versus a maximum energy storage amount of the thermal energy storage medium.

7. The system of claim 1 wherein the thermocline location system comprises a container located within the reservoir and which comprises a fluid, and wherein the object is configured to move within the container as a result of movement of the thermocline within the thermal energy storage device.

8. The system of claim 7 wherein a density of the fluid within the container varies with changes in temperature and the object has a substantially constant density during the changes in temperature.

9. The system of claim 7 wherein the container is configured to permit the object to move upwardly and downwardly corresponding to the changes in the locations of the thermocline.

10. A thermal energy storage device monitoring method comprising:

emitting a first signal towards a position indicating object which is located within a thermal energy storage medium of a reservoir of a thermal energy storage device;

receiving a second signal as a result of the first signal being reflected by the position indicating object; and

using the second signal, providing information regarding the location of a thermocline region within the thermal energy storage medium of the reservoir of the thermal energy storage device.

11. The method of claim 10 further comprising, using the information regarding the location of the thermocline region, providing information regarding an energy state of the thermal energy storage device.

12. The method of claim 10 further comprising, using the information regarding the location of the thermocline region, providing information regarding a representation of an amount of energy stored in the thermal energy storage medium versus a maximum energy storage amount of the thermal energy storage medium.

13. The method of claim 10 wherein the emitting comprises emitting the first signal towards the position indicating object which is within a container which comprises a fluid and which is provided within the thermal energy storage medium, and the providing comprises providing the information regarding a vertical location of the thermocline region within the thermal energy storage medium within the reservoir of the thermal energy storage device which is a water heater.

14. The method of claim 13 wherein the emitting comprises emitting the first signal into a top of the container, and further comprising:

emitting a third signal into a bottom of the container; and

receiving a fourth signal as a result of the third signal being reflected by the position indicating object, and wherein the providing comprises providing using the fourth signal.

15. A system comprising:

a thermocline location system configured to monitor a plurality of locations of a thermocline within a thermal energy storage medium of a thermal energy storage device at a plurality of different moments in time;

circuitry coupled with the thermocline location system and configured to provide information regarding the locations of the thermocline within the thermal energy storage medium of the thermal energy storage device at the different moments in time using the monitoring of the locations of the thermocline; and

wherein the circuitry is configured to use the information regarding the locations of the thermocline to provide information regarding an energy state of the thermal energy storage device at the different moments in time.

16. The system of claim 15 wherein the circuitry is configured to provide the information regarding the energy state of the thermal energy storage device as representations of amounts of energy stored in the thermal energy storage medium at the different moments in time versus a maximum energy storage amount of the thermal energy storage medium.