The amount of energy and power that an Energy Storage System (ESS) is capable of storing serves as its definition (MWh and MW). A power system known as an Energy Storage System (ESS) combines a power grid connection with a Victron inverter/charger, GX device, and battery system. For usage later, when the sun sets, it saves solar energy in your battery during the day. It permits time-shifting power, solar-charged charging, grid support, and power export back to the grid. When an ESS system is able to generate more energy than it can consume and store, it can sell the excess to the grid, and when it does not, it automatically purchases additional energy or power from the grid.

In the ESS system, there must at least be one inverter/charger and also a GX device such as:

Cerbo GX

Venus GX

Why ESS is important

In recent years, distributed generation (DG) has drawn increased attention. This is primarily attributable to DGs' many benefits, which include a decrease in electrical energy loss in the distribution system, a decrease in voltage fluctuations, an increase in reliability, an improvement in power quality, a decrease in energy costs, and ultimately an increase in customer satisfaction. Despite all the advantages that DG has for power systems, connecting these new technologies to the country's energy systems poses some serious issues, including shifting the protection setting, power system stability, and the islanding phenomenon.

DGs may contain several electrical energy generation technologies, such as nonrenewable resources or renewable resources, such as wind and solar power plants (conventional methods). The biggest difficulties arise when using the majority of renewable energy sources, such as wind farms and photovoltaic (PV) systems, as DGs since the output power is unpredictable and changeable. In fact, the use of DGs in a power grid raises extra concerns due to these key characteristics. One of the most suitable solutions in this situation is to use an energy storage system (ESS), which is what is suggested.

When is it appropriate to use ESS?

Use ESS in a self-consumption system, a solar backup system, or a hybrid of the two: For instance, you may consume 30% of the battery's capacity for self-consumption while keeping the remaining 70% as a backup in case the power grid fails.

i). Optimizing self-consumption:

When there is more PV power than is required to run loads, the excess PV energy is stored in the battery. That stored energy is then used to power the loads at times when there is a shortage of PV power. The percentage of battery capacity used for self-consumption is configurable. When utility grid failure is extremely rare it could be set to 100%. In locations where grid failure is common - or even a daily occurrence - you might choose to use just 20% of battery capacity and save 80% for the next grid failure. African countries for example.

ii). Keep batteries 100% charged:

Additionally, ESS can be set up to maintain the batteries' full charge. The only time battery power is used is as a backup in the event of a utility grid failure. The batteries will be replenished once the grid is back up and running, either by the grid or, if available, by solar panels.

Categories of ESS operation:

i). The charging period: This process is applicable using the network electrical energy, during the off-peak intervals when the electrical energy is available at lower prices,

ii).The discharging period: In times of peak the stored energy in an ESS is used. It should be mentioned that in this period the network electrical energy has a higher price and use of DGs is more economical. Accordingly, application of an ESS system is mainly explainable for reducing or even eliminating the uncertainties of renewable DG.

It should be noted that the most popular techniques in ESSs are based on the DC type, so connecting these systems to the national power grids involves power electronic devices much more. In terms of technology, location, capacity, demand, and investment costs, different ESSs can typically be offered.

References

UL 9540: Standard for Energy Storage Systems and Equipment

UL 9540A: Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems

NFPA 855: Standard for the Installation of Stationary Energy Storage Systems