Patent attributes
Methods and systems are provided for realizing energy cost savings through load shifting utilizing a battery bank that may serve as a battery back-up on a premises for providing power in the event of a grid power outage or curtailment. A budget of unreserved cycles of battery charging and discharging is determined, taking into account the rated battery life in terms of both time (e.g., years) and number of cycles. That cycle budget is allocated to days of the year identified as days on which the greatest savings can be realized through load shifting. These days are identified by taking into account the peak and off-peak usage rates applicable on those days, any rate tiers that may be entered as a result of the additional energy expended to load shift, and the round trip efficiency of the charge/discharge cycles. Load shifting is executed in accordance with an established schedule of the identified days, by discharging the batteries during peak usage hours and charging the batteries during off-peak periods. In the event the budget of unreserved cycles exceeds the number of profitable days for load shifting, the depth of discharge on each cycle may be increased to realize greater savings on the scheduled days, at the tolerable cost of losing cycles not expected to be used in any event.
