[NOVEMBER THEMATIC REPORT: ENERGY STORAGE SYSTEM]

The steady expansion of renewable energy sources (RES) had significantly altered the paradigm of enormous, centralized electric energy generators and dispersed loads in the entire electrical system. These days, a lot of renewable energy sources are situated a lot nearer to commercial, industrial, and residential regions. The term "distributed generation" refers to this. Distributed generation is predicted to become more and more obvious in the years to come. Energy sources like the sun and wind are unpredictable and vulnerable to abrupt fluctuations; also, it is difficult to integrate them with existing thermoelectric facilities. Large-scale thermoelectric plants may lower their operational power in light of the ongoing growth of renewable energy sources. The way the electrical system is managed will need to alter in response to the changes brought on by the production of renewable energy. In this report, we will discuss the application of Energy Storage Systems which are devices or systems used to store energy for later use

Energy Time Shift

It is one of the major applications already operated by traditional pumped-storage hydroelectric plants. It consists of “buying” energy when the market price is low (by absorbing energy from the grid, ie: charging the batteries or moving the water on the top reservoir in case of hydroelectric pumping) and selling it when the market price is higher.

The benefits of this application are not strictly related to the economic advantages of selling energy at higher prices. Indeed this “energy moving” contributes to increasing the energy demand when it is lower and decreasing it when higher. This leads to so-called “peak shaving,” reducing the impact of the peaks in both the generation curve and load curve, resulting in a “smooth” curve shape. This is then easier to predict and easier to manage.

 Voltage Control:

Voltage control is a crucial point of an electrical energy system, usually achieved by the reactive power regulation of each generator. The voltage control performed by the energy storage system can also fall into the application category of “power quality” as it is crucial to enhance the quality of the service provided by the distributor system operation.

Frequency Regulation (primary, secondary, and tertiary)

Frequency fluctuations can occur when an electrical system’s generation is not matched to the load.  These variations are mitigated by a complex control system in which energy storage systems can easily operate, particularly those with a quick response time such as pumped-storage hydroelectric systems or electrochemical systems. 

Battery Energy Storage Systems

As mentioned above, there is much importance for energy storage systems and several benefits for the electrical system where an energy storage system is present. The type of energy storage system that has the most growth potential over the next several years is the battery energy storage system.

The benefits of a battery energy storage system include:

• Useful for both high-power and high-energy applications
• Small size in relation to other energy storage systems
• Can be integrated into existing power plants
• Ease of installation
• The price of batteries decreases with continued adoption and availability 

Despite technological progress, storing electrical energy in a universally inexpensive way is an ongoing issue. In terms of cost, storing electrical energy remains quite expensive and the main price reductions are related to economic scale due to the market expansion.