Method and system for load shifting

• US 8,228,034 B2
• Filed: 12/18/2007
• Issued: 07/24/2012
• Est. Priority Date: 12/18/2007
• Status: Expired due to Fees

• Current Assignee: Halton Hills Hydro, Inc.
• Original Assignee: Halton Hills Hydro, Inc.
• Inventors: Guatto, Dan, Skidmore, Art
• Primary Examiner(s): Muralidar, Richard V
• Application Number:
  US11/958,650
• Publication Number:
  US 20090153102A1
• Time in Patent Office: 1,680 Days
• Field of Search: 307/65, 307/66, 320/132, 320134-136
• US Class Current: 320/132
• CPC Class Codes: H01M 10/4207 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H02J 3/32 using batteries with converting means
• CPC Class Codes: H02J 7/0018 using separate charge circuits
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

There is provided a system for storing electrical energy during an off-peak period and distributing the electrical energy to consumers during a peak period. The system includes an energy storage means for storing the electrical energy; a first means for directing the electrical energy produced during the off-peak period into the energy storage means; and a second means for directing the electrical energy from the energy storage means to consumers during the peak period. Preferably, the energy storage means consists of five sodium-nickel-chloride batteries having a specific energy in the range of about 80 to about 200 Wh/kg, preferably about 100 to about 150 Wh/kg, and most preferably about 120 Wh/kg.

Claims

1. A system for storing electrical energy during an off-peak period and distributing the electrical energy during a peak period, wherein the system comprises:

an energy storage means comprising at least two sodium-nickel-chloride batteries having a specific energy in the range of about 80 to about 200 Wh/kg, each battery having a corresponding battery management interface and an operating mode;

a multiple battery server comprising monitoring control software for monitoring the system and for controlling current flow within the system, the multiple battery server being configured to receive data relating to each battery from each corresponding battery management interface;

a first means for directing the electrical energy produced during the off-peak period into the energy storage means comprising at least one charger for converting alternating current into direct current and the multiple battery server controlling the flow of the alternating current into the at least one charger, wherein the direct current is stored in the energy storage means;

a second means for directing the electrical energy from the energy storage means during the peak period comprising a power management cabinet for controlling the discharge of the stored electrical energy from the energy storage means, the power management cabinet configured to receive a discharge signal and a stop discharging signal from the monitoring control software.

2. The system of claim 1, wherein the energy storage means is at least five sodium-nickel-chloride batteries having a specific energy in the range of about 80 to about 200 Wh/kg.

3. The system of claim 2, wherein the energy storage means is at least five sodium-nickel-chloride batteries having a specific energy in the range of about 100 to about 150 Wh/kg.

4. The system of claim 1, wherein the second means further comprises an inverter for inverting the stored electrical energy to alternating current.

5. The system of claim 1, wherein the energy storage means comprises at least one sodium-nickel-chloride battery having a specific energy in the range of about 100 to about 150 Wh/kg.

6. The system of claim 1, wherein the energy storage means comprises at least one sodium-nickel-chloride battery having a specific energy of about 120 Wh/kg.

7. The system of claim 1, wherein the data relating to each battery comprises the corresponding battery'"'"'s voltage, current, temperature and state of charge.

8. The system of claim 1, wherein the operating mode comprises discharge mode, normal charge mode, and fast charge mode.

9. A method of storing electrical energy during an off-peak period and distributing the stored electrical energy to a power grid for use by consumers during a peak period, the method comprising the steps of:

converting electrical energy that is produced during the off-peak period into direct current and directing the electrical energy that is produced during the off-peak period into an energy storage means comprising at least two sodium-nickel-chloride batteries having a specific energy in the range of about 80 to about 200 Wh/kg;

storing the electrical energy in the energy storage means until the peak period; and

inverting the stored electrical energy into alternating current and directing the stored electrical energy from the energy storage means into the power grid for use by the consumers during the peak period, wherein the peak period is when the market cost of the electrical energy is higher than the market cost of the electrical energy during the off-peak period.

10. The method of claim 9, wherein the energy storage means is at least five sodium-nickel-chloride batteries having a specific energy in the range of about 80 to about 200 Wh/kg.

11. The method of claim 10, wherein the energy storage means is at least five sodium-nickel-chloride batteries having a specific energy in the range of about 100 to about 150 Wh/kg.

12. The method of claim 9, wherein the energy storage means is comprises at least one sodium-nickel-chloride battery having a specific energy in the range of about 100 to about 150 Wh/kg.

13. An electrical load levelling system for storing electrical energy during an off-peak period and distributing the electrical energy to consumers during a peak period, wherein the system comprises:

at least one charger for converting alternating current into direct current,

a multiple battery server for controlling the flow of the alternating current into the at least one charger,

at least two energy storage devices for storing the direct current electrical energy from a corresponding charger,

an inverter for inverting the direct current electrical energy into alternating current electrical energy, and

a power management cabinet for controlling the discharge of the stored electrical energy from each storage device to the inverter, and for directing the alternating current electrical energy to the consumers during peak periods,

wherein the each energy storage device is a sodium-nickel-chloride battery having a specific energy in the range of about 80 to about 200 Wh/kg, each energy storage device having a corresponding management interface and an operating mode, the corresponding management interface configured to send data relating to the corresponding battery'"'"'s voltage, current, temperature and state of charge to the multiple battery server.

14. The system of claim 13, wherein the energy storage device is at least five sodium-nickel-chloride batteries having a specific energy in the range of about 80 to about 200 Wh/kg.

15. The system of claim 14, wherein the energy storage device is at least five sodium-nickel-chloride batteries having a specific energy in the range of about 100 to about 150 Wh/kg.

16. The system of claim 13, wherein the energy storage device is comprises at least one sodium-nickel-chloride battery having a specific energy in the range of about 100 to about 150 Wh/kg.

17. The system of claim 13, wherein the energy storage device is comprises at least one sodium-nickel-chloride battery having a specific energy of about 120 Wh/kg.

18. The system of claim 13, wherein the operating mode comprises discharge mode, normal charge mode, and fast charge mode.