Summary
A BESS can fulfill different functions within an electrical system. Its value is not only in storing energy, but in delivering that energy at the right time and under an appropriate strategy.
Why are there different applications?
Not all storage projects have the same goal. Some seek to reduce demand costs, others support critical loads, others support renewable plants and others provide services to the electrical system.
Therefore, before defining the capacity of a BESS, a basic question must be answered: What problem should the system solve?
Peak shaving
The peak shaving consists of reducing the maximum demand of an installation. In many industries, part of the electricity cost depends on peak consumption. If a plant demands a lot of power for short periods, it may face significant charges.
A BESS can be unloaded during these peaks, reducing the demand seen from the network. For this application to work, the load curve, the duration of the peaks, their frequency and the energy necessary to reduce them must be analyzed.
Power backup
In critical facilities, an electrical interruption can generate economic losses, operational risks or security problems. A BESS can power critical loads during an outage, either alone or combined with gensets, UPS, solar generation or microgrids.
To design backup, it is necessary to define which loads will be powered, for how long, with what autonomy and under what operating conditions.
Renewable integration
Solar and wind generation depends on natural conditions. Solar energy varies with radiation and time; the wind varies with the wind. A BESS allows surpluses to be stored and delivered when generation decreases or when demand increases.
This can help reduce discharges, improve the use of a renewable plant and make energy more manageable.
Frequency control
The electrical frequency reflects the balance between generation and demand. If generation is missing, the frequency drops. If there is excess generation, the frequency increases. A BESS can respond quickly by injecting or absorbing power, making it useful for auxiliary services.
Voltage and reactive power control
Depending on the inverter, control and grid operator requirements, a BESS can participate in voltage and reactive power control strategies. This can be useful in weak networks, renewable plants, substations with voltage restrictions or industrial installations with variable loads.
energy arbitrage
Arbitrage consists of charging when energy is cheaper and discharging when it is more expensive. Although it sounds simple, it requires analyzing the market, rates, degradation, efficiency, battery cycles and applicable commercial rules.
Microgrids
In a microgrid, the BESS can act as a stability and backup element. It can be coordinated with solar, diesel, public grid and critical loads to maintain supply under normal or emergency conditions.
common mistake
A common mistake is wanting the same BESS to do everything at the same time: reduce demand, support loads, sell energy, control frequency and absorb solar surpluses. It is possible to combine applications, but it must be prioritized. Stored energy is limited and each strategy affects system availability.
Conclusion
The value of a BESS depends on its application. A good project does not start by asking “what battery do I buy”, but rather “what do I need the system to do”.
When the main application is well defined, storage stops being just a piece of equipment and becomes integrated as an operational, energetic and economic decision of the project.
If you need to define the application, scope or strategy of a BESS system, check out our service. BESS engineering and energy storage.