Why do you need an energy storage system?

Camille Petit

Integrating energy storage systems is a path to consider for solar developers looking to build up more self-sufficient installations. In micro-grids already harnessing cheaper energy through the sun, adding an energy storage solution with a battery will address the challenge of renewable energy intermittency and help users decrease energy bills.

Discover in this article how monitoring and controlling solutions can help Battery Energy Storage System (BESS) achieve reliability and efficiency.

What is a micro-grid?

A micro-grid is an energy distribution network which is self-sufficient in its energy production and distributions. It relies on the local means of producing electricity and is, therefore, best suited and widely used in well-grid connected, poor-grid connected areas, or totally isolated projects. Microgrid can operate alongside the national grid but in some cases, is built to run completely independent of it.

Why install a Battery Energy Storage System for microgrids?

The idea of micro-grids is being adopted by many independent users on a large scale. However, the micro-grid has its own share of limitations like intermittency and mismatch in power factor. A battery energy storage system is what helps the owners overcome these limitations and help garner the full potential of the system.

A battery energy storage system, or BESS, helps the micro-grid in several ways:

  • Increase the reliability of the grid by providing a back-up system: the battery storage system can be a reliable power source by reacting instantaneously in case of grid failure or downtime ;
  • Lower dependency on fuel and minimize carbon footprint: the storage system can allow solar systems to store excess energy during the daytime which can then be used during the night ;
  • Increase solar penetration: when the energy production is more than the load requirement, the excess energy can be stored ;
  • Increase owners’ net profits by reducing their utility bills. BESS can be configured in such a way that they shift load during peak hours or provide energy during the high-demand hours.

Power Grid (if available) : Whether it is on grid or off grid the set of the frequency of the microgrid will be different, either assured by the grid, the gensets or the batteries if needed.    

Benefits of Energy Storage Systems: 4 main applications

The benefits of BESS systems depend on the configuration they are being used in. Two main factors are influencing this configuration: connection and reliability of the grid as well as energy prices.

BESS for grid-tied application

For grid-tied applications, where the micro-grid is connected to the main grid, BESS systems can help owners to reduce their bills. In developed countries, although the supply of electricity is ensured, there is a major difference between prices during the off-hours and peak-hours. Users can reduce their bills by shifting their load to micro-grids during peak hours.

Owners can avoid penalties by energy companies by reducing their load when their demand is above the maximum power purchase value. BESS systems can also be used to regulate power factor in order to avoid cos-phi penalties.

BESS for grid-tied applications in regions with expensive energy rates

In some countries, buying energy from the national grid is in fact more expensive than storing self-produced energy. For example, in Puerto Rico, the grid quality is average but the main aim of the users is to reduce the energy bought from the national grid. People prefer to produce their own energy and store it. The energy from the main grid has become a secondary choice or more of a back-up option.

BESS for unreliable grid application

In countries like South Africa, where the national grid is not reliable at all and frequent black-outs and load-shedding is a norm, people tend to use micro-grids with the aim of becoming self-sufficient in terms of energy demand. BESS proves to be a source of reliable backup during hours of load-shedding.

BESS for off-grid application

Lastly, off-grid micro-grids are established in rural areas or isolated sites where the cost of providing electricity is too high. Micro-grids are established in such areas to avoid costly infrastructure to connect the area with the national grid, for example rural areas of Africa or mountainous regions of China. Battery Energy Storage Systems are ideally suited for such applications where they are used to store energy and provide it according to the demand.

Elum’s solution for BESS

Elum Energy offers a range of control and monitoring solutions for Energy Storage Systems, suited for different requirements on a micro-grid. Micro-grids operators can achieve reliability and efficiency through the use of Elum Energy’s products which can allow them to attain flexibility in order to meet the high diversity of grid connection requirements in the different countries Elum operates in.
Elum ePowerControl ES is a 100% standardized energy management system dedicated to battery storage systems (BESS) eventually coupled with other energy sources such as PV or diesel generators.

It aims to standardize as much as possible the BESS management for small/medium-scale applications, providing a smart, plug & play, and cost-effective control solution. Through an advanced control algorithm, it allows the installer to select the suited battery charging strategy allowing him to maximize PV penetration and battery bank life, and reduce diesel fuel costs.

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