A digital controller controls contingency discharges of a utility from a reservoir to a plant during a first time period and compensatory charges from the plant back to the reservoir during a second time period. The utility can be electric power. The plant and reservoir are connected by a grid. The reservoir may be any electric power storage device. When the utility is electric power, the contingency discharges make up for the power not generated by the plant due to an accident. The compensatory charges replenish the reservoir. The digital controller may use a transfer function nomogram to control the compensatory charges based on the contingency discharges.