Energy Storage Applications

Utility scale energy storage applications can provide a myriad of services to the grid.  A partial list of services is listed below.  Sovereign Energy Storage works with utilities to understand their needs, implementing systems that the specific customer requirements.

Voltage Support

The voltage on transmission and distribution lines has to be sustained within certain limits. Due to losses and other effects the voltage limits can be violated. One measure to control the voltage is the injection or absorption of reactive power.

This can be supplied by systems which are solely installed for this purpose and also energy storage systems which can supply reactive power in addition to their primary purpose.


Frequency Regulation

Energy storage systems can balance the fluctuations between electricity generation and electrical load and manage the variability in the grid’s frequency .

The frequency rises if generation is higher than demand and the frequency drops if demand is higher than generation.

By charging energy storage systems, the demand of electricity can be increased and by discharging the storage systems generation can be increased. Therefore energy storage systems can balance generation and demand and by this supply frequency control.


Peak Load Shifting

By the means of energy storage systems it is possible to reduce peaks in power demand and therefore reduce costs for seldom used generation and transmission capacities.

The distribution and transmission lines as well as generation capacity are dimensioned according to the peak power demand. The cost for the overall power system but also the grid connection for the individual costumer is driven by the peak load.


Black Start

This capability provides power and energy after a system failure. Many units of the power system are not able to restart after such an event.

Energy storage systems can be used to provide energy to help other units restart and provide a reference frequency for synchronization of other generation units.


Renewables Integration & Spinning Reserve

In power systems with very high shares of renewables, the tasks of spinning reserve can no longer be delivered by conventional power plants. Either renewable power generators operating below rated capacity or energy storage systems can be used.

Spinning reserve is the power generation capacity which can be activated on decision of the system operator and which is provided by devices that are synchronized to the grid and able to affect the active power. In order to do that, power plants have to be operated below maximum rated capacity. This causes reduced cost effectiveness and potentially an increase in specific emissions.



Load Leveling/Peak Shaving

Load leveling reduces fluctuations in energy demand during one day. During times with low demand, energy is stored and during times with high demand, energy is fed back into the grid.

In power systems with high shares of renewables, the predictable pattern of shifting excess power from night hours to peak load times during the day will gradually disappear.


Distribution-level Outage Mitigation

In order to provide outage mitigation at the distribution level, the storage device would have to be located downstream of a system outage. For example, if a distribution line had a planned or unplanned outage, and an energy storage device downstream (on the load side) of that outage were available for discharge, customers could continue to have electric service during the outage, if an alternate “tie” can also be maintained with the source system.


Price Arbitrage

Energy storage systems can reduce energy costs by charging the system with low priced, off-peak electricity and discharging it later when energy prices are high.


Energy Storage Applications