Method and apparatus for delivering power using external data

• US 9,406,094 B2
• Filed: 08/14/2013
• Issued: 08/02/2016
• Est. Priority Date: 08/14/2012
• Status: Active Grant

• Current Assignee: Stem, Inc.
• Original Assignee: Stem, Inc.
• Inventors: Kearns, Ben, Burlinson, Jon, Stevens, Drew
• Primary Examiner(s): Masinick, Michael D
• Application Number:
  US13/967,256
• Publication Number:
  US 20140049109A1
• Time in Patent Office: 1,084 Days
• Field of Search: 307/52, 700/295, 700/297
• US Class Current: 1/1
• CPC Class Codes: G05B 13/026 using a predictor
• CPC Class Codes: G05B 2219/39361 Minimize time-energy cost
• CPC Class Codes: G05F 1/66 Regulating electric power
• CPC Class Codes: G06Q 50/06 Energy or water supply
• CPC Class Codes: H02J 13/00 Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
• CPC Class Codes: H02J 13/00002 characterised by monitoring
• CPC Class Codes: H02J 13/00034 the elements or equipment being or involving an electric power substation
• CPC Class Codes: H02J 3/00 Circuit arrangements for ac mains or ac distribution networks
• CPC Class Codes: H02J 3/003 Load forecast, e.g. methods or systems for forecasting future load demand
• CPC Class Codes: H02J 3/32 using batteries with converting means
• CPC Class Codes: H02J 4/00 Circuit arrangements for mains or distribution networks not specified as ac or dc
• CPC Class Codes: Y02E 40/70 Smart grids as climate change mitigation technology in the energy generation sector
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y02P 80/10 Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier
• CPC Class Codes: Y04S 10/14 Energy storage units
• CPC Class Codes: Y04S 10/30 State monitoring, e.g. fault, temperature monitoring, insulator monitoring, corona discharge
• CPC Class Codes: Y04S 10/50 Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications

Abstract

A control system for an energy storage system located behind a utility meter uses a unique, feedback-based, communication and control method to reliably and efficiently maximize economic return of the energy storage system. Operating parameters for the energy storage system are calculated at an external, centralized data center, and are selected to prevent electrical power demand of an electric load location from exceeding a specified set-point by discharging energy storage devices, such as DC batteries, through a bidirectional energy converter during peak demand events. The control system can operate autonomously in the case of a communications failure.

Claims

1. A system for controlling the transfer of energy between an electric load location and an electric grid, comprising:

a power monitor in electric communication with an electric line that is coupled to an electric meter of an electric load location, wherein the electric meter is configured to measure energy transferred to the electric load location through the electric line;

an optimization engine configured to receive one or more external inputs and create a set of operating parameters based on the one or more external inputs; and

a system controller configured to use the set of operating parameters to;

control a first transfer of energy from the electric line to an energy storage device, and

control a second transfer of energy from the energy storage device to the electric line to maintain a rate of energy flow associated with the second transfer of energy below a threshold value, wherein the threshold value varies with time.

2. The system of claim 1, wherein the set of operating parameters are derived from simulations of energy use at the electric load location, and the simulations are performed by the optimization engine.

3. The system of claim 1, wherein the system controller comprises a set-point controller configured to vary the threshold value.

4. The system of claim 1, wherein the one or more external inputs are selected from a group consisting of weather information, sunrise and sunset information, power usage cost information, utility'"'"'s billing period, geographic location, local solar production, local incident light, customer type, electric load location building specifications, grid operator data and time data.

5. The system of claim 1, wherein the system controller is configured to transmit information to the optimization engine, and the optimization engine is configured to update the set of operating parameters based on the information to vary the rate of energy flow through the electric line as a function of time.

6. The system of claim 1, wherein the one or more external inputs received by the optimization engine comprise a predicted power demand associated with the electric load location at a first time of day, and wherein the system controller comprises a set-point controller configured to change the threshold value from a first value to a second value based on the predicted power demand.

7. The system of claim 6, wherein the set-point controller is further configured to increase the threshold value from the second value to a third value based on determining that a state of charge of the energy storage device is below a second threshold value.

8. The system of claim 1, wherein the electric line is associated with an electric utility that delivers power to the electric load location.

9. A system for controlling energy transferred between an electric grid and an electric load location, comprising:

an optimization engine configured to receive one or more external inputs and create one or more operating control curves based on the one or more external inputs; and

a distributed energy storage device comprising a system controller and a power monitor configured to monitor an electric line that is coupled to an electric meter, wherein the system controller is configured to;

compare the one or more operating control curves to information received from the power monitor and an energy storage device,

control a first transfer of energy from the electric line to the energy storage device based on the comparison, and

control a second transfer of energy from the energy storage device to the electric line, based on the comparison, to maintain a rate of energy flow associated with the second transfer of energy below a threshold value, wherein the threshold value varies with time.

10. The system of claim 9, wherein the one or more operating control curves comprise a battery state-of-charge curve that is used by the system controller to determine an amount of energy to transfer to the electric line based on a measured amount of charge in the energy storage device.

11. The system of claim 10, wherein the one or more operating control curves further comprise:

a discrete or continuous demand set-point curve that is used by the system controller to determine two or more demand set-points, wherein the discrete or continuous demand set-point curve has a first value for a first time period and a second value for a second time period, the first value being different than the second value.

12. The system of claim 9, wherein the system controller further comprises a computer readable medium that is configured to store instructions that cause a processor to perform a process comprising:

receiving a first set of operating parameters that are created based on one or more received external inputs; and

based on the first set of operating parameters, varying the energy transfer from the energy storage device to the electric line to cause a rate of the second transfer of energy to remain below a threshold value, wherein the threshold value varies with time.

13. A system for controlling energy transferred between an electric grid and an electric load location, comprising:

an energy source;

a power monitor configured to monitor an electric line that is coupled to an electric meter of an electric load location, wherein the electric meter is used by a utility to determine power delivered to one or more electrical components disposed in the electric load location through the electric line;

a bi-directional power converter electrically coupled to the energy source and the electric line; and

a system controller configured to;

control a first transfer of energy from the energy source to the electric line via the bi-directional power converter, and

control a second transfer of energy from the electric line to the energy source, via the bi-directional power converter, to maintain a rate of energy flow associated with the second transfer of energy below a threshold value, wherein the threshold value varies with time.

14. The system of claim 13, further comprising:

an optimization engine configured to receive one or more external inputs and create a set of operating parameters based on the one or more external inputs, and

the system controller is configured to receive the set of operating parameters and use the set of operating parameters to control the second transfer of energy between the energy source and the electric line via the bi-directional power converter.

15. The system of claim 14, wherein the system controller is configured to transmit information to the optimization engine, and the optimization engine is configured to update the set of operating parameters based on the information to vary the power delivered through the electric line as a function of time.

16. The system of claim 13, wherein the energy source comprises one or more batteries.

17. A computer readable medium configured to store instructions executable by a processor of a host device, the instructions when executed by the processor causing the processor to:

monitor a first rate of energy transfer from an electric line to an electric load location;

control a second rate of energy transfer from the electric line to an energy storage device based on control parameters, wherein the control parameters are generated based on a simulation that is performed using forecast information, and wherein controlling the second rate of energy transfer alters the first rate of energy transfer; and

control a third rate of energy transfer from the energy storage device to the electric line, based on the control parameters, to maintain the third rate of energy transfer below a threshold value, wherein the threshold value varies with time.

18. The computer readable medium of claim 17, wherein the control parameters are generated by:

generating the forecast information by creating a forecast for a first time period based on one or more received external inputs; and

cleansing the one or more received external inputs by adjusting the information received from a first external input so that a time scale associated with the information received from the first external input matches a time scale associated with information received from a second external input.

19. The computer readable medium of claim 18, wherein the forecast is created based on received forecasted coefficient data and received historical coefficient data.

20. The computer readable medium of claim 18, wherein the external inputs are created from information selected from a group consisting of weather information, sunrise and sunset information, power usage cost information, utility'"'"'s billing period, geographic location, local solar production, local incident light, customer type, electric load location building specifications, grid operator data and time data.

21. The computer readable medium of claim 17, wherein the control parameters comprise optimum demand set-points as a function of time and one or more battery curves that comprise a set of time-based battery state-of-charge curves.

22. The computer readable medium of claim 21, wherein the one or more battery state-of-charge curves comprise a flat battery curve, a continuously varying battery curve, a stepped battery curve, or a forecasted battery curve.

23. The computer readable medium of claim 17, wherein the control parameters are further generated by:

receiving electrical pricing information for the first time period; and

generating the control parameters based on the electrical power pricing information.

24. The computer readable medium of claim 23, wherein the control parameters are further generated by:

receiving electrical power tariff information for the first time period;

receiving energy storage device operation information, wherein the energy storage device operation information comprises at least one of the following;

state-of-charge information received from the energy storage device;

total charge capacity information received from the energy storage device;

charge discharge efficiency rating information received from the energy storage device;

or

current energy capacity information received from the energy storage device; and

generating the control parameters based on a simulation that includes the electrical power tariff information.