Dispatchable power from a renewable energy facility

• US 8,866,334 B2
• Filed: 03/02/2011
• Issued: 10/21/2014
• Est. Priority Date: 03/02/2010
• Status: Active Grant

• Current Assignee: Turbocell LLC
• Original Assignee: ICR Turbine Engine Corporation
• Inventors: Donnelly, Frank Wegner, Dewis, David William
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): DHILLON, JAGDEEP S
• Application Number:
  US13/039,088
• Publication Number:
  US 20110215640A1
• Time in Patent Office: 1,329 Days
• Field of Search: 307/21, 307/64, 307/72, 307/31, 307/57, 307/112, 307/77, 290/44, 290/2, 322/37, 322 20- 21, 322/36, 220/734
• US Class Current: 307/21
• CPC Class Codes: H02J 1/10 Parallel operation of dc sources
• CPC Class Codes: H02J 2300/10 The dispersed energy generation being of fossil origin, e.g. diesel generators
• CPC Class Codes: H02J 2300/22 The renewable source being solar energy
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 2300/26 involving maximum power point tracking control for photovoltaic sources maximum power point systems in particular G05F1/67
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/466 Scheduling the operation of the generators, e.g. connecting or disconnecting generators to meet a given demand
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers

Abstract

The placement of fully available prime movers having a DC output at a location inside or adjacent to an inverter-based intermittently available renewable energy site is disclosed. The fully available prime movers add reliability to an unreliable energy asset that is reaching its maximum penetration within the grid due to its unpredictability and the requirement for additional spinning reserves in other parts of the grid. The present invention can provide a portion or all of the power to an intermittently available renewable power generating facility so that the power output to the power grid is dispatchable power. In particular, a method and means are disclosed to utilize high-efficiency engines operated on various fuels some of which may be non-fossil fuels to maintain a constant power output from an otherwise intermittent power generating facility.

Claims

1. A method of converting a renewable power plant to a dispatchable power plant, comprising:

providing a computer system with a processor;

providing at least one intermittently available renewable energy source;

providing at least one fully available energy source;

providing a DC bus;

wherein the at least one intermittently available renewable energy source is associated with an existing power electronics interface that connect the DC bus to a regulated AC power grid, the existing power electronics interface adapted to transform DC voltage to regulated AC voltage;

converting power from the at least one intermittently available renewable energy source to DC power on a DC bus;

the processor accessing whether the power delivered by the at least one intermittently available renewable energy source will be less than a predetermined amount of power;

operating the at least one fully available energy source to supply sufficient DC power to the DC bus to supply an amount of power requested by a regulated AC power grid up to the maximum rated power of the at least one intermittently available renewable energy source; and

supplying the power requested by the regulated AC power grid utilizing the existing power electronics interface, wherein the at least one fully available energy source is only associated with the existing power electronics interface as the existing power electronics interface are capable of carrying the maximum rated power of the at least one intermittently available renewable energy source.

2. The method of claim 1, wherein the at least one fully available energy source provides dispatchable power, wherein each of the at least one fully available energy source comprises at least one of a gas turbine engine, a reciprocating engine and a fuel cell, and power control apparatuses to provide DC electrical power to a DC bus.

3. The method of claim 1, wherein the at least one intermittently available energy source is at least one of a photovoltaic array, a solar thermal plant, a wind turbine and a water turbine, wherein the predetermined amount of power is an existing or probable electrical power requirement by the AC power grid.

4. A non-transitory computer readable medium comprising processor executable instructions to perform the steps of claim 1.

15. The method of claim 1 wherein the DC bus receives electrical power from at least one of the at least one fully available energy source and at least one intermittently available renewable energy source, and further comprising providing power to an inverter, the inverter converting the DC electrical power to an AC electrical power for supply to the regulated AC power grid.

16. The method of claim 1, further comprising providing at least one DC energy storage device, and supplying power from the at least one DC energy storage device to the DC bus.

17. The method of claim 16, further comprising:

setting an energy storage system power control apparatus voltage to a level sufficient to send electrical power from an energy storage system to the DC bus; and

setting the at least one fully available energy source'"'"'s power control apparatus voltages to levels sufficient to send electrical energy from the one or more fully available energy source to the DC bus.

18. The method of claim 17, further comprising:

engaging and/or adjusting a determined amount of power from the at least one fully available energy source required to provide sufficient electrical power to the grid to satisfy the determined amount;

as the at least one fully available energy source supplies the predetermined amount of power, adjusting the energy storage system power control apparatus voltage to a lower first level to decrease an amount of electrical power supplied by the energy storage system to the DC bus.

22. The method of claim 1, further comprising an energy storage system that supplies energy to the DC bus to reduce the amount of power required by the at least one fully available energy source.

23. The method of claim 22, wherein the energy storage system can be charged by the at least one intermittently available energy source.

24. The method of claim 23, wherein an amount of power being requested by the AC power grid is less than that available from the at least one intermittently available energy source.

25. The method of claim 22, wherein the energy storage system can call for more power than the intermittent source can provide.

26. The method of claim 22, wherein the energy storage system provides power while the at least one fully available energy sources are preparing to provide power.

5. A system for converting a renewable power plant to a dispatchable power plant, comprising:

a DC bus;

at least one available renewable energy source electrically connected to the DC bus, wherein output power of the at least one renewable energy source is convertible to DC power;

an existing power electronics interface connecting the DC bus to a regulated AC power grid wherein the existing power electronics interface is capable of carrying the maximum rated power of the at least one renewable energy source, the existing power electronics interface associated with the at least one available renewable energy source;

at least one fully available energy source also interconnected to the existing power electronics interface, the output power of the at least one fully available energy source is convertible to DC power by the existing power electronics interface; and

wherein the power on the DC bus is regulated by the existing power electronics interface so as to maintain a requested power level by the grid up to the maximum rated power of the at least one renewable energy source.

6. The system of claim 5, wherein the at least one fully available energy source comprises a prime power source, wherein the at least one fully available energy source provides dispatchable power, and wherein the at least one fully available energy source comprises a power control apparatus to provide DC electrical power to a DC bus.

7. The system of claim 6, wherein the at least one available renewable energy source is at least one of a photovoltaic array, a solar thermal plant, a wind turbine and a water turbine, wherein the requested power level is an existing or probable electrical energy requirement by the AC power grid.

8. The system of claim 5, further comprising:

a processor operable to set an energy storage system power control apparatus voltage to a level sufficient to send electrical energy from an energy storage system to the DC bus and set at least one fully available energy source power control apparatus voltages to a level sufficient to send electrical power from the at least one fully available energy source to the DC bus.

9. The system of claim 8, wherein the processor engages and/or adjusts a determined amount of power from the at least one fully available energy source required to provide sufficient electrical energy to the grid to satisfy the requested power level and, as the at least one fully available energy source supplies the requested power level, adjusts the energy storage system power control apparatus voltage to a lower first level to decrease an amount of electrical power supplied by the energy storage system to the DC bus.

10. The system of claim 9, wherein the processor is operable to set an energy storage system power control apparatus voltage to a level sufficient to charge an energy storage system.

11. The system of claim 5, further comprising:

a wind turbine comprising a rotor to rotate in response to air movement and produce mechanical power;

a generator operable to convert the mechanical power into alternating current AC electrical energy; and

a power control apparatus operable to convert the AC electrical energy into direct current (“

DC”

) electrical energy that is forwarded to the DC bus.

12. The system of claim 11, wherein the at least one fully available energy source is located in a nacelle of the wind turbine.

13. The system of claim 11, wherein at least one fully available energy source is located in a tower of the wind turbine.

14. The system of claim 11, wherein at least one fully available energy source is located adjacent to a tower of the wind turbine.

19. The system of claim 5, wherein the at least one fully available energy source provides an aggregate power output substantially equal to the maximum rated power of the at least one renewable energy source.

20. The system of claim 5, wherein the at least one DC energy storage source is connected to the DC bus.

21. The system of claim 5, wherein the DC bus is electrically connected to an inverter.

27. A system for converting a renewable power plant to a dispatchable power plant, comprising:

a DC bus;

at least one available renewable energy source electrically connected to the DC bus, wherein output power of the at least one renewable energy source is convertible to DC power;

an existing power electronics interface connecting the DC bus to a regulated AC power grid wherein the existing power electronics interface is capable of carrying the maximum rated power of the at least one renewable energy source;

at least one fully available energy source, the output power of the at least one fully available energy source is convertible to DC power;

wherein the power on the DC bus is regulated by the existing power electronics interface so as to maintain a requested power level by the grid up to the maximum rated power of the at least one renewable energy source;

a wind turbine comprising a rotor to rotate in response to air movement and produce mechanical power;

a generator operable to convert the mechanical power into alternating current AC electrical energy;

a power control apparatus operable to convert the AC electrical energy into direct current (“

DC”

) electrical energy that is forwarded to the DC bus; and

wherein the at least one fully available energy source is located in a nacelle of the wind turbine, a tower of the wind turbine, or adjacent to a tower of the wind turbine.

28. The system of claim 27, wherein the at least one fully available energy source comprises a prime power source, wherein the at least one fully available energy source provides dispatchable power, and wherein the at least one fully available energy source comprises a power control apparatus to provide DC electrical power to a DC bus.

29. The system of claim 28, wherein the at least one available renewable energy source is at least one of a photovoltaic array, a solar thermal plant, a wind turbine and a water turbine, wherein the requested power level is an existing or probable electrical energy requirement by the AC power grid.

30. The system of claim 27, further comprising:

a processor operable to set an energy storage system power control apparatus voltage to a level sufficient to send electrical energy from an energy storage system to the DC bus and set at least one fully available energy source power control apparatus voltages to a level sufficient to send electrical power from the at least one fully available energy source to the DC bus.

31. The system of claim 30, wherein the processor engages and/or adjusts a determined amount of power from the at least one fully available energy source required to provide sufficient electrical energy to the grid to satisfy the requested power level and, as the at least one fully available energy source supplies the requested power level, adjusts the energy storage system power control apparatus voltage to a lower first level to decrease an amount of electrical power supplied by the energy storage system to the DC bus.

32. The system of claim 31, wherein the processor is operable to set an energy storage system power control apparatus voltage to a level sufficient to charge an energy storage system.

33. The system of claim 27, wherein the at least one fully available energy source provides an aggregate power output substantially equal to the maximum rated power of the at least one renewable energy source.

34. The system of claim 27, wherein the at least one DC energy storage source is connected to the DC bus.

35. The system of claim 27, wherein the DC bus is electrically connected to an inverter.

36. An electrical power generating system for converting a renewable power plant to a dispatchable power plant, comprising;

at least one renewable energy source that outputs DC electrical power to a DC bus;

the DC bus and an inverter connected to an electrical utility grid wherein the DC bus and inverter transmits power to the electrical utility grid up to a rated power level of the at least one renewable energy source;

at least one back-up power source comprising an engine and a fuel supply, the at least one back-up power source outputting DC electrical power to the DC bus; and

a computer system that, based on the demand requested by the electrical utility grid, commands the requested power to be delivered to the electrical utility grid, up to the rated power level.

37. A method of converting a renewable power generating facility to a dispatchable power generating facility, comprising:

providing a DC bus and an inverter connected to an electrical utility grid;

providing at least one renewable energy source outputting DC electrical power to the DC bus;

providing at least one back-up power source comprising an engine and a fuel supply, the at least one back-up power source outputting DC electrical power to the DC bus;

providing a computer system;

determining, by the computer system, an amount of electrical power being delivered by the at least one renewable energy source to the electrical utility grid;

determining, by the computer system, the power requested by the electrical utility grid;

operating, by the computer system, the at least one back-up power source to supply power to the DC bus equal to the power requested by the electrical utility grid minus the amount of electrical power being delivered by the at least one renewable energy source, up to a rated power level of the at least one renewable energy source.