Method and system for scheduling the discharge of distributed power storage devices and for levelizing dispatch participation

Abstract

Disclosed is a computerized method for dispatching energy from distributed resources in a discharge event so that the energy stored in individual devices is ilevelized, or so that an operator request is met. Evaluation of event parameters may be deferred. The method may be utilized to dispatch energy from plug-in electric vehicles. Systems and methods to account for electricity dispatched to or from electric vehicles are disclosed. Systems and methods for incentivizing consumers to participate in a dispatch event or curtail energy use are disclosed.

1 . A method for dispatching energy from a plurality of distributed storage resources in a discharge event so that the energy stored in each of the plurality of distributed resources is levelized, comprising:
 receiving, in a computer, a dispatch request comprising an amount of power required during a dispatch event and a duration of the discharge event;   determining, in the computer, accomplishability of the dispatch request by:
 determining an aggregate rate of discharge for the plurality of distributed energy resources based on the rates of discharge at which each of the individual resources of the plurality of distributed resources are capable of producing; 
 determining if the determined aggregate rate of discharge is sufficient to meet the amount of power required to satisfy the dispatch request; 
 determining if the determined aggregate rate of discharge can be maintained at all times during the dispatch event, and if so, identifying the dispatch request as accomplishable: 
   causing, if the dispatch request is determined to be accomplishable, the computer to determine the amount of energy to be discharged from each of the plurality of distributed resources during the dispatch event so as to reduce the variance among the stored energy levels of the plurality of distributed energy resources;   scheduling the dispatch of each of the plurality of distributed resources to participate in the dispatch event by:
 implementing a bin packing algorithm to select the start and stop times of the discharge of each of the plurality of distributed resources during the dispatch event; and 
 tilting the dispatch schedule by adding a fractional time offset to intervals in each bin used by the bin packing algorithm; 
   sending dispatch instructions to each of the plurality of distributed resources to participate in the scheduled dispatch event.   
     
     
         2 . The method of  claim 1 , wherein the step of scheduling the dispatch of each of the plurality of distributed resources further comprises:
 adding a ramp up time and a ramp down time to each distributed resource participating in the dispatch event, ensuring that all ramp up and ramp down transitions of the plurality of distributed resources occur in pairs.   
     
     
         3 . The method of  claim 1 , wherein the step of scheduling the dispatch of each of the plurality of distributed resources further comprises:
 prioritizing the participation of each of the plurality of distributed resources in order of their respective potential discharge duration potential.   
     
     
         4 . The method of  claim 1 , wherein the rates of discharge at which each of the plurality of resources are capable of discharging energy are approximately the same. 
     
     
         5 . The method of  claim 1 , wherein the rates of discharge at which each of the plurality of resources are capable of discharging energy are not all the same. 
     
     
         6 . The method of  claim 1 , wherein the variance among the stored energy levels of each of the plurality of distributed energy resources is maximally brought to a state where each resource has a fraction of the total remaining energy of each of the plurality of distributed energy resources proportional to its discharge rate. 
     
     
         7 . The method of  claim 1 , wherein the amount of energy each of the plurality of distributed energy resource is capable of storing is approximately the same, and the
 sending dispatch instructions to each of the plurality of distributed resources to participate in the scheduled dispatch event.   
     
     
         2 . The method of  claim 1 , wherein the step of scheduling the dispatch of each of the plurality of distributed resources further comprises:
 adding a ramp up time and a ramp down time to each distributed resource participating in the dispatch event, ensuring that all ramp up and ramp down transitions of the plurality of distributed resources occur in pairs.   
     
     
         3 . The method of  claim 1 , wherein the step of scheduling the dispatch of each of the plurality of distributed resources further comprises:
 prioritizing the participation of each of the plurality of distributed resources in order of their respective potential discharge duration potential.   
     
     
         4 . The method of  claim 1 , wherein the rates of discharge at which each of the plurality of resources are capable of discharging energy are approximately the same. 
     
     
         5 . The method of  claim 1 , wherein the rates of discharge at which each of the plurality of resources are capable of discharging energy are not all the same. 
     
     
         6 . The method of  claim 1 , wherein the variance among the stored energy levels of each of the plurality of distributed energy resources is maximally brought to a state where each resource has a fraction of the total remaining energy of each of the plurality of distributed energy resources proportional to its discharge rate. 
     
     
         7 . The method of  claim 1 , wherein the amount of energy each of the plurality of distributed energy sources is capable of storing is approximately the same, and the accomplishable is now unaccomplishable, providing an operator making the request a notification that the dispatch request is no longer accomplishable. 
     
     
         12 . The method of  claim 1 , wherein the plurality of distributed resources are mobile energy resources and the step of determining accomplishability further comprises:
 receiving historical arrival and departure times at a location of each of the plurality of distributed resources; and   determining the probability that a dispatch request can be satisfied using plurality of distributed mobile resources based on the historical arrival and departure times of the plurality of distributed resources.   
     
     
         13 . The method of  claim 12 , wherein the probability determination is performed for regular time steps of the duration of the dispatch event to ensure that a sufficient number of distributed mobile resources will be available to satisfy the dispatch request during the duration of the dispatch event. 
     
     
         14 . The method of  claim 13 , further comprising:
 determining accomplishability using the historical data of the amount of stored energy available upon arrival at a location from each of the plurality of mobile distributed resources.   
     
     
         15 . The method of  claim 14 , further comprising:
 weighting a distribution of a predicted arrivals at that location with the historical amount of stored energy available upon arrival of a mobile resource at a location; and, combining the weighted distribution with the energy available in distributed mobile resources that are actually available at a given time in order to compute accomplishability.   
     
     
         16 . The method of  claim 13 , further comprising:
 selecting the length of the time step length so as to minimize the number of distributed mobile resources that are removed from participation in the dispatch event while also minimizing the number of calculations resulting from the number of potential distributed mobile resources used to calculate the accomplishability.   
     
     
         17 . A method for dispatching energy from a plurality of distributed mobile storage resources in a discharge event so that the energy stored in each of the plurality of distributed mobile storage resources is levelized, comprising:
 causing a computer to receive a dispatch request comprising an amount of power required during a dispatch event and a duration of the dispatch event;   receiving the historical arrival times, departure times, and stored energy available, of each of the plurality of distributed mobile storage resources at a location;   predicting the number of arrivals, departures, and the amount of stored energy available for the plurality of distributed mobile storage resources during the dispatch event, the prediction being based, in part, on the historical arrival times, departure times, and the stored energy available for each distributed mobile storage resource;   weighting a distribution of the predicted arrival times of mobile resources with the predicted amount of stored energy available for the plurality of distributed mobile storage resources and combining the weighted distribution with the number of mobile resources actually available;   computing the accomplishability of the dispatch request by aggregating the combined weighted distribution at multiple time steps during the predicted dispatch and determining if the aggregate rate of discharge capability of each of the plurality of mobile resources is sufficient to meet the amount of power required to satisfy the dispatch request at each time step in the dispatch event, and if so, identifying the dispatch event as accomplishable;   causing, if the dispatch event is determined to be accomplishable the computer to determine the amount of energy to be discharged from each of the plurality of distributed mobile resources during the dispatch event so as to maximally reduce the variance among the stored energy levels of the plurality of distributed energy resources; p 1  scheduling the dispatch of each distributed mobile storage resource of the plurality of distributed mobile storage resources to participate in the dispatch event using a bin packing algorithm to select the start and stop times of the discharge of each of the plurality of distributed mobile storage resources;   tilting the dispatch schedule by adding a fractional time offset to intervals in each bin used in the bin packing algorithm;   sending the discharge instructions to the plurality of distributed resources according to the dispatch schedule;   adding a ramp up time and a ramp down time to each distributed mobile storage resource participating in the dispatch event, ensuring that all ramp up and ramp down transitions of the plurality of distributed mobile storage resources occur in pairs; and,   repeating the accomplishability step each time a new dispatch request is created or cancelled, and if a dispatch request that was previously determined not to be accomplishable is now determined to be accomplishable, providing an operator making the request a notification that the dispatch request is now accomplishable, and if a dispatch request that was previously determined to be accomplishable is now unaccomplishable, providing a utility operator making the request a notification that the dispatch request is no longer accomplishable.