Over recent years, South Africa has faced major grid instability with frequent planned and unplanned power cuts and rising electricity prices disrupting daily life and harming the country’s economy. In response, the government is accelerating a shift toward new energy sources—especially renewables—through large investments and by bringing more private players, including the commercial and industrial (C&I) sector, into power generation. The African continent’s strong solar potential is making solar-plus-storage an increasingly attractive investment rather than an optional add-on.
That said, battery storage is a complex technology, and there are two main criteria that C&I customers, as well as EPCs, are typically concerned about.
A survey by TÜV Rheinland revealed that safety issues were the biggest concern among the constraints for the development of energy storage systems.
Unlike utility-scale ESS, C&I projects pose a greater safety risk, being installed in areas with higher population density as well as in the vicinity of valuable assets such as machinery, server rooms and combustible goods.
Safety has always been a cornerstone of Huawei’s design, no matter the product. This fact is reflected in its energy storage systems, the company priding itself on setting safety requirements that are more stringent than the existing industry standards.
Instead of incorporating one or two common safety features, Huawei’s ESS features a holistic cell to consumption (C2C) safety design, making the system safe for use from its smallest unit all the way to its entirety. The C2C system also boasts a dual architecture, focusing on both electrical and thermal link safety.
The biggest risk to an energy storage system, electrically caused, is short circuits. Nearly all fires related to electrical components can be attributed to short circuits, making it an extremely crucial risk to address. Huawei does this by implementing an advanced short circuit prevention and isolation system in its ESS.
At cell level, the company uses a dual intelligent detection system, which can detect 13 types of cell faults and effectively prevent most short circuits.
At pack level, the greatest risk leading to short circuits is poor or rapidly degrading insulation. Huawei’s ESS uses a six-sided insulation that isolates all components, significantly reducing both the risk of contact between isolated parts and therefore the risk of short circuits.
When it comes to the entire system, most ESS have four-layer protection, which leaves a blind spot, typically at the rack level contactors, Huawei’s five-layer protection enhancing safety by eliminating this blind spot. In addition, while most conventional energy storage systems have a shutdown time of over a second, the Huawei ESS can shut down within an impressive 5 milliseconds when it detects a short circuit.
Finally, at the consumption level, Huawei uses 24-hour, triple RCD (residual current device) protection that detects current leakage, resulting in the avoidance of short circuits as well as improved system health and reliability.
The importance of thermal safety in an ESS cannot be overstated, which is why the company implements the same cell to consumption safety system to prevent thermal runaway.
The Huawei ESS uses high-temperature-resistant silicone foam insulation around each battery cell, reducing heat flow between cells, and also uses an advanced liquid cold plate that houses a dual-loop heat-dissipation design to rapidly dissipate cell heat.
Pack level safety is ensured by a positive-pressure oxygen blocking design, which stops external gases from entering the battery pack due to a pressure difference, effectively preventing oxygen from entering the battery pack and thus reducing the likelihood of fire.
Huawei secures system level thermal safety through a design that minimizes the risk of cabinet explosion. It does this by using a directional gas exhaust, connecting the pressure relief valve at the rear of the battery pack to the duct at the rear to form an L-shaped directional duct. This prevents accumulation of combustion gases inside the cabinet and greatly reduces the possibility of an explosion.
In the highly unlikely event that combustion gases do accumulate inside the cabinet, steadily raising pressure to the point of explosion, the Huawei ESS prevents an uncontrolled explosion by using a top explosion vent with ropes. In this case, only the top panel is subject to explosion and is held in place by ropes, unlike conventional designs, where all parts of a cabinet undergo explosion, often resulting in risk of injury and cabinet disintegration.
To ensure that its storage systems surpass even the strictest safety standards, Huawei has not only designed a cutting-edge safety architecture, but also tested it rigorously, commissioning TÜV Rheinland to test and certify system safety, resulting in an endorsement with the world’s highest certification.
In November, Huawei Digital Power’s C&I Hybrid Cooling Grid Forming ESS passed a stringent extreme ignition test witnessed by TÜV Rheinland. Conducted at a national key fire safety lab, the test was the industry’s first fire assessment of an ESS in compliance with the latest UL 9540A:2025 standard, establishing a new safety benchmark for the sector.
The test was designed to create the industry’s most demanding verification environment, evaluating the safety performance of ESSs under extreme ignition scenarios. A pack-level overcharge method was used to trigger simultaneous thermal runaway in 60 battery cells, simulating a “worst-case upon ignition” scenario. Compared with tests involving only single or a few cells, the severity of this assessment increased exponentially.
When the fire temperature reached 961℃, the highest cell temperature of an adjacent ESS was only 45.3℃, well below the threshold for opening the cell explosion-proof valve. The system fully complied with UL 9540A:2025 requirements, with no fire propagation between units.
The recorded peak heat release rate (HRR) was 3 MW, total combustion lasting less than three hours before self-extinguishing. Under open-door burning conditions, the system also rapidly managed heat release, demonstrating superior thermal management capability.
The second most important factor for C&I customers is efficiency. An energy storage system’s efficiency dictates how much power is utilized and how much is lost in conversion losses during charging and discharging. The better a system’s efficiency, the higher its return on investment (ROI). Although battery technology has advanced rapidly to become more efficient than ever, different battery brands can have noticeably different round-trip efficiencies (RTE).
Unsurprisingly, a lot of the elements that make the Huawei ESS extremely safe are also the same that make its battery highly efficient, an example being the hybrid cooling technology upgrading conventional thermal management from a single-mode regime to an adaptive multimode control strategy. In simple terms, the thermal management involves a scenario-based, environment-aware cooling that cuts auxiliary power consumption by 30%, boosting the system’s efficiency.
Thermal management is the crucial link between safety and efficiency. A properly designed thermal management system creates both a safe and efficient system. Huawei uses a wind-liquid smart cooling architecture, which combines the advantages of both air- and liquid-cooled systems to maximise efficiency.
The company commissioned the University of Pretoria for proof of concept (POC) testing of its 215 kWh C&I storage system, testing confirming that the system has a striking round-trip efficiency (RTE) of 91.3%, meaning that less than a tenth of the energy is lost in charging-discharging and related DC-AC conversions.