Battery Energy Storage Systems (BESS) are revolutionising the way we generate, store, and use energy. They provide resilience, efficiency, and sustainability—helping businesses, communities, and industries transition to a cleaner future. However, as with any energy-intensive system, some risks must be carefully managed to ensure safe and efficient operation.
At Energy Renaissance, we believe that a well-designed system is a safe system. That’s why we’ve built our batteries with multiple layers of defence-grade protection to ensure reliability, prevent potential risks, and give you peace of mind. One of the most important risks to understand—and control—is thermal runaway.
Let’s take a closer look at what it is, how it happens, and most importantly, how we prevent it in our BESS solutions.
Thermal runaway is a well-known but rare phenomenon in lithium-ion batteries that occurs when a cell overheats beyond its safe limit and can no longer cool itself down. Instead of stabilising, it triggers a chain reaction where excess heat causes the internal materials to break down, releasing even more heat. If left unchecked, this heat can spread to nearby cells, leading to thermal propagation, gas venting, fire, or, in extreme cases, an explosion. Understanding and managing this process is key to ensuring battery safety and reliability.
How does thermal runaway occur?
Thermal runaway can be triggered by various factors, including:
Overcharging or over-discharging
Exceeding safe voltage levels can generate excessive heat.
Impact, punctures, or mechanical stress can lead to short circuits.
Manufacturing defects
Poor assembly or material defects can create internal short circuits.
External heat sources
High ambient temperatures or nearby fires can contribute to overheating.
Electrical malfunctions
Faulty energy management systems or inverters may force the battery to operate beyond safe limits.
Safety is at the heart of everything we do, and we’ve taken a multi-layered approach to ensure our batteries operate within safe limits at all times.
Our proprietary Battery Management System (‘Renaissance superBMS™’), designed in collaboration with CSIRO, continuously monitors each cell’s voltage and temperature at both the pack and rack level. If a single cell or pack exceeds safe thresholds, the system automatically disconnects the entire rack—stopping the chain reaction before it can escalate.
Even with early detection, batteries can sometimes vent gas if they are damaged or failing. To prevent gas from building up within the system, we’ve designed our BESS to safely release pressure. Each battery cell has a built-in pressure relief valve, so gas is released safely instead of building up inside. In addition, our battery enclosures feature pressure relief vents that direct gas away from workers and sensitive equipment.
superRack™ outdoor pressure relief vent
If a fire does start inside the battery, we have integrated fire suppression devices within our enclosures that are specifically designed to suffocate fires before they can spread by depleting oxygen. These systems are calibrated to match the enclosure’s air volume, ensuring effective fire suppression while minimising environmental impact.
Beyond physical threats, cyberattacks pose a serious risk to BESS by potentially manipulating the Energy Management System (EMS) or inverter, forcing batteries to operate outside safe limits, which can lead to overheating and failure. To combat this, our rack-level BMS features an automatic disconnection protocol that immediately shuts down operations if unauthorised commands attempt to manipulate power levels.
Having the right thermal and fire management controls in place ensures your system operates reliably with minimal risk.
Even with the most advanced prevention systems, being prepared for worst-case scenarios is critical. That’s why we take fire safety seriously. Here are the steps we take to ensure our products are fire safe:
Tarro Fire Brigade visits Renaissance One
We know that energy storage is a long-term investment, and safety is non-negotiable.
A single thermal runaway event could mean catastrophic consequences, but with smart technology, robust engineering, and proactive fire safety, we ensure our systems are built to prevent, detect, and contain risks before they become disasters.
Our mission is to provide safe, high-performance battery solutions without compromise. We refuse to cut corners when it comes to safety because we understand what’s at stake. Our safe energy storage solutions have been specifically designed to protect what matters most–people, businesses, and communities.
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