Building control systems with optimization of equipment life cycle economic value while participating in IBDR and PBDR programs
A central plant includes an electrical energy storage subplant configured to store electrical energy, a plurality of generator subplants configured to consume one or more input resources, including discharged electrical energy, and a controller. The controller is configured to determine, for each time step within a time horizon, an optimal allocation of the input resources. The controller is configured to determine optimal allocation of the output resources for each of the subplants in order to optimize a total monetary value of operating the central plant over the time horizon.
1. A central plant configured to generate and provide resources to a building, the central plant comprising:
an electrical energy storage subplant configured to store electrical energy purchased from a utility and to discharge the stored electrical energy;
a plurality of generator subplants configured to consume one or more input resources comprising the discharged electrical energy and to generate one or more output resources to satisfy a resource demand of the building; and
a controller configured to determine, for each time step within a time horizon, an optimal allocation of the input resources and the output resources for each of the subplants in order to optimize a total monetary value of operating the central plant over the time horizon;
wherein the controller determines the optimal allocation of the input resources and the output resources by optimizing a value function comprising a monetized cost of capacity loss for the electrical energy storage subplant predicted to result from battery degradation due to a potential allocation of the resources;
wherein the controller predicts the monetized cost of capacity loss prior to allocating the resources, uses the predicted cost of capacity loss to optimize the allocation of the input resources and the output resources, and uses the optimal allocation of the input resources and the output resources to operate each of the subplants.
2. The central plant of claim 1 , wherein the optimal allocation of the resources comprises an allocation of the stored electrical energy to the generator subplants for at least some of the time steps and an allocation of the stored electrical energy to an incentive-based demand response (IBDR) program for at least some of the time steps.
3. The central plant of claim 1 , wherein determining the optimal allocation of resources comprises determining an amount of the electrical energy stored or discharged by the electrical energy storage subplant for each of the time steps.
4. The central plant of claim 1 , wherein the expected revenue from participating in an IBDR program and an expected cost of the resources purchased from the utility.
5. The central plant of claim 1 , wherein the value function further comprises a penalty cost of equipment degradation resulting from a potential allocation of the resources;
wherein the controller predicts the penalty cost of equipment degradation prior to allocating the resources and uses the predicted penalty cost to optimize the allocation of the input resources and the output resources.
6. The central plant of claim 1 , wherein the value function further comprises a penalty cost of equipment start/stops resulting from a potential allocation of the resources;
wherein the controller predicts the penalty cost of equipment start/stops prior to allocating the resources and uses the predicted penalty cost to optimize the allocation of the input resources and the output resources.
7. The central plant of claim 1 , wherein the controller is configured to perform:
a first optimization that optimizes the total monetary value of operating the central plant over the time horizon; and
a second optimization that optimizes a total value of purchasing equipment of the central plant as well as the total monetary value of operating the central plant over the time horizon.
8. A method for operating a central plant to generate and provide resources to a building, the method comprising:
storing electrical energy purchased from a utility in an electrical energy storage subplant and discharging the stored electrical energy from the electrical energy storage subplant;
consuming one or more input resources at a plurality of generator subplants to generate one or more output resources to satisfy a resource demand of the building, the one or more input resources comprising the discharged electrical energy;
determining, for each time step within a time horizon, an optimal allocation of the input resources and the output resources for each of the subplants in order to optimize a total monetary value of operating the central plant over the time horizon, wherein determining the optimal allocation of the input resources and the output resources comprises optimizing a value function comprising a monetized cost of capacity loss for the electrical energy storage subplant predicted to result from a potential allocation of the resources;
predicting the monetized cost of capacity loss prior to allocating the resources and using the predicted cost of capacity loss to optimize the allocation of the input resources and the output resources; and
using the optimal allocation of the input resources and the output resources to operate each of the subplants.
9. The method of claim 8 , wherein determining the optimal allocation of the resources comprises determining an allocation of the stored electrical energy to the generator subplants for at least some of the time steps and an allocation of the stored electrical energy to an incentive-based demand response (IBDR) program for at least some of the time steps.
10. The method of claim 8 , wherein determining the optimal allocation of the resources comprises determining an amount of the electrical energy stored or discharged by the electrical energy storage subplant for each of the time steps.
11. The method of claim 8 , wherein the value function comprises expected revenue from participating in an IBDR program and an expected cost of the resources purchased from the utility.
12. The method of claim 8 , wherein the value function further comprises a penalty cost of equipment degradation resulting from a potential allocation of the resources;
the method further comprising predicting the penalty cost of equipment degradation prior to allocating the resources and using the predicted penalty cost to optimize the allocation of the input resources and the output resources.
13. The method of claim 8 , wherein the value function further comprises a penalty cost of equipment start/stops resulting from a potential allocation of the resources;
the method further comprising predicting the penalty cost of equipment start/stops prior to allocating the resources and using the predicted penalty cost to optimize the allocation of the input resources and the output resources.
14. The method of claim 8 , wherein determining the optimal allocation of the input resources and the output resources comprises:
performing a first optimization that optimizes the total monetary value of operating the central plant over the time horizon; and
performing a second optimization that optimizes a total value of purchasing equipment of the central plant as well as the total monetary value of operating the central plant over the time horizon.
15. A building management system comprising:
building equipment that consume electrical energy and generate thermal energy for use in satisfying a thermal energy load of a building;
thermal energy storage configured to store at least a portion of the thermal energy generated by the building equipment and to discharge the stored thermal energy;
electrical energy storage configured to store electrical energy purchased from a utility and to discharge the stored electrical energy; and
a controller configured to determine, for each time step within a time horizon, an optimal amount of thermal energy generated by the building equipment, an optimal amount of thermal energy stored or discharged by the thermal energy storage, and an optimal amount of electrical energy stored or discharged by the electrical energy storage in order to optimize a total monetary value of operating the building management system over the time horizon;
wherein the controller determines the optimal amounts of thermal energy and electrical energy by optimizing a value function comprising a monetized cost of capacity loss for the electrical energy storage predicted to result from battery degradation due to a potential allocation of the thermal energy and electrical energy;
wherein the controller predicts the monetized cost of capacity loss prior to allocating the thermal energy and electrical energy, uses the predicted cost of capacity loss to optimize the amounts of thermal energy and electrical energy, and uses the optimal amounts of thermal energy and electrical energy to operate each of the building equipment, the thermal energy storage, and the electrical energy storage.
16. The building management system of claim 15 , wherein the electrical energy discharged from the electrical energy storage is consumed by the building equipment.
17. The building management system of claim 15 , wherein the electrical energy discharged from the electrical energy storage is sold to an outside entity as part of an incentive-based demand response (IBDR) program in exchange for revenue that contributes to the total monetary value of operating the building management system over the time horizon.
18. The building management system of claim 15 , wherein the value function further comprises at least one of:
a monetized cost of capacity loss for the electrical energy storage; and
a penalty cost of control actions associated with the building equipment.