Battery storage is a key part of the transition to renewable energy. They help to balance the mismatch between energy production and consumption by storing excess energy during periods of low consumption and releasing it during peak periods. However, like any technology, battery storage brings certain safety challenges that need to be addressed.
Major safety risks One of the most significant safety concerns is the risk of fire. Batteries, especially those with high capacity and power, can produce significant amounts of heat. If they are not properly managed, a thermal reaction can occur that can cause a fire or even an explosion.
Another factor is environmental contamination. Batteries contain a variety of chemicals that can be harmful to the environment if they leak. It is crucial to ensure that battery storage facilities are designed and sited to minimise the risk of leakage of these materials.
Safety strategies Several strategies must be put in place to ensure the safety of battery storage sites. The first is advanced temperature management and battery health monitoring. This includes the use of sensors and cooling systems to ensure that batteries remain within safe temperature limits.
Physical security is also important. Storage sites should be protected from unauthorised access and equipped with detection and extinguishing systems in case of fire.
What makes up a BESS container?
- Container
- Batteries
- BMS (Battery Management System)
- PMS (Power Management System)
- PCS (Power Conditioning System)
- Refrigeration
- Fire protection
BESSapplications
BESS have many useful apps that contribute to their popularity and widespread use, including:
Replenishment of renewable resources
Solar panels and wind turbines are limited in that they only produce electricity when the sun is out or the wind is blowing. Supplementing these renewable energy sources with a BESS allows users to benefit from the electricity generated by the BESS when the renewable energy sources are not producing electricity.
PEAK SHAVING
BESS enables cost savings during peak hours of the day when energy is more expensive. Users can draw power from the batteries during these peak times and then let the batteries charge during the cheaper nighttime hours.
Load balancing
Throughout the day, the generating capacity of power plants is ramped up and down to meet changing electricity demand. This puts a strain on the system. ESS can help balance the demand curve by charging when electricity demand is low and discharging when it is high.
Uninterrupted electricity supply
Power outages and interruptions can be some of the most disruptive and significant problems that facilities face. ESSs can provide an immediate response to power interruptions and are capable of keeping hospitals, data centers, and homes connected to the grid.
Risks associated with BESS
The use of lithium-ion batteries can create the potential for a number of fire risks. Battery safety risks do exist, it is important to remember that energy storage technologies are robust and reliable. Risk mitigation is critical to the safe operation of these systems, and a proper understanding of each risk is key. For example, thermal runaway, a common hazard in BESS, is a Class B fire. This is not the same as an electrical fire or a Class C fire. If your fire protection design is for a Class C fire, you may not be prepared for this catastrophic threat. The concentration levels for a Class B fire are different than a Class C fire, and suppression alone will not stop a thermal runaway. So, let’s lay out the hazards one by one.
Thermal Escape
Thermal runaway describes the rapid, uncontrolled release of heat from a battery cell; the battery generates more heat than it can effectively dissipate. A runaway event occurs when one battery cell causes a chain reaction that heats neighboring cells. Continuous heating for subsequent cells often leads to a battery fire or explosion, which can become the ignition source for larger battery fires.
Stuck energy
Even after participating in a fire, ESSs can still pose a hazard. As with most electrical equipment, there is a risk of electrical shock. But unique to ESSs is that there is still energy in the system that can pose a risk. Once damaged, the terminals are difficult to discharge, which can cause a risk to those involved in the restoration. Stuck energy can also cause a fire to reignite hours or even days later.
Toxic and flammable gases
When batteries experience a thermal runaway, they most often produce toxic and flammable gases. If the gases do not ignite before they reach the lower explosive limit, this can lead to the creation of an explosive atmosphere inside the ESS room or container.
Deep-seated fires
Most ESSs are usually made up of batteries that are stored in a protective metal or plastic case inside larger enclosures. Although these layers of protection help prevent damage to the system, they can also prevent water from reaching the source of the fire. Therefore, large quantities of water are needed to effectively combat the heat generated by ESS fires, and it is often difficult to cool the hottest part of the fire.
Accidental discharge
One of the main risks of ESS is accidental discharge of the extinguishing system. Depending on the extinguishing agent used in the system, there will be a major operational interruption to the unit. This includes costly cleanup and potential damage to the equipment.
