Reduction of operational cost using energy storage management and demand response

• US 9,367,108 B2
• Filed: 04/06/2013
• Issued: 06/14/2016
• Est. Priority Date: 06/28/2012
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Asghari, Babak, Sharma, Ratnesh
• Primary Examiner(s): Ali, Mohammad
• Assistant Examiner(s): Azad, Md Abul
• Application Number:
  US13/858,027
• Publication Number:
  US 20140005852A1
• Time in Patent Office: 1,165 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: H02J 2310/10 The network having a local or delimited stationary reach
• CPC Class Codes: H02J 2310/64 The condition being economic, e.g. tariff based load management
• CPC Class Codes: H02J 3/14 by switching loads on to, or off from, network, e.g. progressively balanced loading
• CPC Class Codes: H02J 3/32 using batteries with converting means
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: Y02B 70/3225 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 20/222 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 50/10 Energy trading, including energy flowing from end-user application to grid

Abstract

A method for managing demand or load includes, upon receipt of a demand response signal or a load management request from a utility to change the price of electricity, determining the cost of energy from a local battery, and if the cost of energy from battery is higher than the cost of electricity from the utility, shedding power from one or more devices based on the utility price, and otherwise discharging power from the battery to reduce a net load on the grid without any actual load reduction.

Claims

1. A method for managing demand or load, comprising:

receiving input demand by a real-time power and load management controller;

information including different generation power, storage state of charge, and end-user demand;

determining a discharge pattern of a storage used to estimate the battery lifetime and determining discharge event for the local battery as;

2. The method of claim 1, comprising applying a levelized cost model for a storage unit which provides the cost of energy from the battery to be compared with a grid price.

3. The method of claim 2, comprising applying a storage life esitmator to determine when a storage unit is to be replaced based on a current discharge requirment.

4. The method of claim 2, comprising applying economic parameters including inflation and interest rates, and dividing a net present cost of the storage unit over a project life-time to calculate a cost of energy from the battery.

5. The method of claim 2, comprising applying a cost of energy from the battery with a grid price to make a decision on shedding the load or discharging the battery.

6. The method of claim 1, comprising deciding in real-time if a load management procedure is done through an actual load reduction or a battery discharge.

7. The method of claim 1, comprising determining a mismatch power in the microgrid as follows:

P_mismatch=P_DG+P_{scheduled-grid}−

P_load

where P represents power.

8. The method of claim 1, comprising performing load management without user interaction by specifying a percentage of a load shedding based on a grid price in advance.

9. The method of claim 1, comprising determining a cost of energy from a battery in a secondary management unit that estimates a discharge current and DOD of the battery if it is going to be used to meet the power shortage as follows:

10. The method of claim 1, comprising applying demand response management without the user interaction by specifying a percentage of a load shedding based on a grid price in advance.

11. The method of claim 1, comprising:

detecting an unbalance in a supply and a demand based on a measured distributed generation (DG) output and a load demand; and

if a DG generation of power is more than the demand and an energy storage unit is not fully charged, applying the excess energy generation to charge a storage unit.

12. A system for energy management, comprising:

an energy storage unit;

a computer coupled to a distributed generator (DG) and a grid;

a primary management unit for detecting an unbalance in a supply and a demand based on a measured distributed generation output and a load demand;

computer code for receiving input demand by a real-time power and load management controller;

information including different generation power, storage state of charge, and end-user demand;

computer code for determining a discharge pattern of a storage used to estimate the battery lifetime and determining discharge event for the local battery as;

13. The system of claim 12, comprising computer code for applying a levelized cost model for the storage unit which provides the cost of energy from the battery to be compared with a grid price.

14. The system of claim 13, comprising computer code for applying a storage life esitmator to determine when a storage unit is to be replaced based on a current discharge requirment.

15. The system of claim 13, comprising computer code for applying economic parameters including inflation and interest rates, and dividing a net present cost of the storage unit over a project life-time to calculate a cost of energy from the battery.

16. The system of claim 12, comprising computer code for applying a cost of energy from the battery with a grid price to make a decision on using the grid or discharging the battery.

17. The system of claim 12, comprising computer code for deciding in real-time if a demand response execution (load shedding) results in cost saving.

18. The system of claim 12, comprising computer code for determining a mismatch power in the microgrid as follows:

P_mismatch=P_DG+P_{scheduled-grid}−

P_load

where P represents power.

19. The system of claim 12, comprising computer code for performing load management without user interaction by specifying a percentage of the load shedding based on a grid price in advance.

20. The system of claim 12, comprising computer code fordetermining a cost of energy from a battery in a secondary management unit that estimates a discharge current and DOD of the battery if it is going to be used to meet the power shortage as follows:

21. The system of claim 12, comprising computer code for applying demand response management without the user interaction by specifying a percentage of a load shedding based on a grid price in advance.