Method and system for operating a flow battery system based on energy costs
View Patent ↗A method and system for storing and/or discharging electrical energy that has a cost, which method includes steps of: (a) providing a flow battery system comprising at least one flow battery cell and a controller; (b) operating the flow battery cell at a power density having a first value; and (c) changing the power density at which the flow battery cell is operated from the first value to a second value as a function of the cost of the electrical energy, wherein the power density is changed using the controller, and wherein the second value is different than the first value.
1. A method for at least one of storing and discharging electrical energy that has a cost, comprising:
providing a flow battery system comprising at least one flow battery cell and a controller;
operating the flow battery cell at a power density having a first value; and
changing the power density at which the flow battery cell is operated from the first value to a second value as a function of at least one of a cost value of electrical energy input into the system or a cost value of electrical energy discharged by the system, wherein the power density is changed using the controller, and wherein the second value is different than the first value.
2. The method of claim 1 , wherein the flow battery cell is operated to convert input electrical energy into chemical energy and store the chemical energy within the flow battery system.
3. The method of claim 2 , further comprising the step of determining the cost value of the electrical energy input into the system as a function of time at which the energy is input into the system using the controller.
4. The method of claim 3 ,
wherein the step of determining the cost value of the electrical energy input into the system as a function of time includes the controller referencing a schedule of input electrical energy cost value as a function of time.
5. The method of claim 3 , wherein the controller changes the power density from the first value to the second value when the cost value of the input electrical energy is one of greater than, equal to, and less than a certain predetermined value.
6. The method of claim 3 , wherein the step of determining the cost value of the electrical energy input into the system as a function of time includes the controller predicting the input electrical energy cost value as a function of time.
7. The method of claim 6 , wherein the controller is adapted to predict the input electrical energy cost value as a function of time using an algorithm.
8. The method of claim 1 , wherein the controller changes the power density at which the flow battery cell is operated from the first value to the second value to at least partially offset the cost of the electrical energy during peak hours.
9. The method of claim 1 , wherein the flow battery system is operated at a round trip efficiency that changes between a first efficiency value and a second efficiency value, and wherein there is at least a twenty five percent difference between the first and second efficiency values.
10. The method of claim 1 , wherein the flow battery system operates at a first efficiency value when the power density of the flow battery cell is operated at the first value, wherein the flow battery system operates at a second efficiency value when the power density of the flow battery cell is operated at the second value, wherein there is at least a ten percent difference between the first and second efficiency values, and wherein the first and second efficiency values comprise one of charge efficiency values and discharge efficiency values.
11. The method of claim 2 , further comprising the step of determining the cost value of the electrical energy discharged from the system as a function of time at which the electrical energy is discharged.
12. The method of claim 11 , wherein the step of determining the cost value of the electrical energy discharged from the system as a function of time includes the controller referencing a schedule of electrical energy cost value as a function of time.
13. The method of claim 11 , wherein the step of determining the cost value of the electrical energy discharged from the system as a function of time includes the controller predicting the input electrical energy cost value as a function of time.
14. The method of claim 1 , wherein the step of changing the power density at which the flow battery cell is operated from the first value to a second value, includes changing the power density as a function of an operational efficiency value of the system.
15. A method for operating a flow battery system, comprising the steps of:
providing a flow battery system comprising one or more flow battery cells, a controller, a first storage tank containing a first electrolyte solution, and a second storage tank containing a second electrolyte solution, wherein the controller is adapted to selectively control a flow of the first electrolyte solution between the first storage tank and the flow battery cell, and a flow of the second first electrolyte solution between the first storage tank and the flow battery cell; and
selectively operating the flow battery system alternately between an energy storage mode and an energy discharge mode using the controller, which controller is adapted to selectively operate the flow battery system based on one or more cost parameters.
16. The method of claim 15 , wherein when the controller operates the system in the energy storage mode, the controller selectively operates the system in a first mode associated with acquiring electrical energy input into the system at a first cost value or a second mode associated with acquiring electrical energy input into the system at a second cost value, which second cost value is greater than the first cost value;
wherein in the first mode the controller operates the system to convert input electrical energy into chemical energy at a first power density rate, and wherein the system operates at a first efficiency when operating at the first power density rate; and
wherein in the second mode the controller operates the system to convert input electrical energy into chemical energy at a second power density rate, and wherein the system operates at a second efficiency when operating at the second power density rate; and
wherein the first power density rate is greater than the second power density rate, and the first efficiency is less than the second efficiency.
17. The method of claim 15 , wherein the cost parameters include at least one of: a) a cost value of electrical energy input into the system during the energy storage mode of operation; b) a cost value of operating the flow battery system during the energy storage mode and energy discharge mode; or c) a cost value of electrical energy discharged from the system during energy discharge mode.
18. The method of claim 17 , further comprising the step of determining the cost value of the electrical energy input into the system as a function of time.
19. The method of claim 18 , wherein the step of determining the cost value of the electrical energy input into the system as a function of time includes the controller referencing a schedule of input electrical energy cost value as a function of time.
20. The method of claim 17 , further comprising the step of determining the cost value of the electrical energy discharged from the system as a function of time at which the electrical energy is discharged.
21. The method of claim 20 , wherein the step of determining the cost value of the electrical energy discharged from the system as a function of time includes the controller referencing a schedule of electrical energy cost value as a function of time.
22. The method of claim 17 , wherein the step of selectively operating the flow battery system alternately between an energy storage mode and an energy discharge mode using the controller includes changing a power density at which the flow battery cell is operated from the first value to a second value based on the operational efficiency value of the system.