Solar powered system with grid backup

• US 8,138,630 B2
• Filed: 09/22/2009
• Issued: 03/20/2012
• Est. Priority Date: 09/22/2009
• Status: Expired due to Fees

• Current Assignee: Noribachi Corporation (Lumination Lighting & Technology, Inc.)
• Original Assignee: eBay Inc.
• Inventors: Dibachi, Rhonda, Dibachi, Farzad
• Primary Examiner(s): Deberadinis, Robert L.
• Application Number:
  US12/564,623
• Publication Number:
  US 20110068624A1
• Time in Patent Office: 910 Days
• Field of Search: 307/65
• US Class Current: 307/65
• 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: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/35 with light sensitive cells
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y02E 70/30 Systems combining energy storage with energy generation of non-fossil origin

Abstract

A system includes a solar power subsystem that receives power from one or more solar power arrays. A storage control subsystem is coupled to the solar power subsystem to charge a battery from the power received by the solar power subsystem. A grid power control subsystem having an AC to DC converter receives power from a power grid and provides DC voltage to the storage control subsystem. A balance of system control system controls the amount of power received from the power grid as a function of a load, battery charge and received power by the solar power subsystem. The solar array and battery may be sized to provide sufficient power under normal operating conditions, with power being drawn from the grid during abnormal operation conditions.

Claims

1. A method comprising:

receiving power from a solar array;

using the received power from the solar array to charge a battery;

applying power from the battery to power a load;

drawing power from a power grid as a function of the power drawn from the battery to power the load and the power received from the solar array without providing power back to the grid;

monitoring a battery drain rate;

determining expected power to be received from the solar array;

determining if the battery has sufficient power to power the load prior to the solar array providing power to sufficiently power the load and recharge the battery; and

drawing power from the grid if sufficient power from the solar array is not expected.

2. The method of claim 1 and further comprising:

determining a power requirement to power a load in normal operating conditions; and

determining sizes for the solar array and the battery to provide sufficient power to the load during normal operating conditions.

3. The method of claim 2 wherein power is drawn from the grid during abnormal operating conditions.

4. The method of claim 3 wherein abnormal operating conditions are defined as within selected boundary operating conditions.

5. The method of claim 4 wherein the size of the solar array is no larger than that needed to supply sufficient power to the load within the selected boundary operating conditions.

6. The method of claim 1 and further comprising:

monitoring power from the load, wherein the load comprises multiple loads; and

reducing power to selected loads as a function of power received from the solar array and available battery power.

7. The method of claim 6 and further comprising turning off selected loads when insufficient power from the battery and solar array is available.

8. The method of claim 6 wherein power is reduced to selected loads as a function of a predetermined priority for each load.

9. The method of claim 6 wherein power is reduced as a function of time of day.

10. The method of claim 1 wherein the battery is charged in accordance with a charge profile for the battery dependent on battery size and chemistry.

11. A method comprising:

determining total power requirements for multiple loads for operation during normal operating conditions;

determining sizes for a solar array and a battery to provide sufficient power to the loads during normal operating conditions; and

selecting a controller to control providing power to the loads and charging battery such that power is drawn from a grid connection during operation outside normal operating conditions.

12. A system comprising:

a solar power subsystem that receives power from one or more solar power arrays;

a storage control subsystem coupled to the solar power subsystem to charge a battery from the power received by the solar power subsystem;

a grid power control subsystem having a AC to DC converter to receive power from a power grid and provide DC voltage to the storage control subsystem; and

a balance of system control system to control the amount of power received from the power grid as a function of a load, battery charge and received power by the solar power subsystem.

13. The system of claim 12 wherein the solar power arrays include photovoltaic arrays.

14. The system of claim 12 wherein the solar power arrays have a size limited to provide sufficient power under normal operating conditions.

15. The system of claim 14 wherein balance of system control system draws power from the grid during abnormal operating conditions.

16. The system of claim 15 wherein abnormal operating conditions are defined as within selected boundary operating conditions.

17. The system of claim 16 wherein the size of the solar arrays is no larger than that needed to supply sufficient power to the load within the selected boundary operating conditions.

18. The system of claim 12 and further comprising:

a battery controller to monitor a battery drain rate;

wherein the balance of system control system determines expected power to be received from the solar array, determines if the battery has sufficient power to power the loads prior to the solar array providing power to sufficiently power the loads and recharge the battery, and controls the grid power control subsystem to draw power from the grid if sufficient power from the solar array is not expected.

19. The system of claim 12 and further comprising:

an application control subsystem to monitor power needed by the load, and to reduce power provided to selected loads as a function of power received from the solar array and available battery power.

20. The system of claim 19 wherein the application control subsystem turns off selected loads when insufficient power from the battery and solar array is available.

21. The system of claim 19 wherein power is reduced to selected loads as a function of a predetermined priority for each load.

22. The system of claim 19 wherein power is reduced as a function of time of day.

23. The system of claim 12 wherein the storage control subsystem comprises multiple batteries and wherein each battery is charged in accordance with a charge profile for the battery dependent on battery size and chemistry.