Imagine yourself attending a Euro 2024 match, for example. It's evening already, and all of a sudden, the lights go out. The whole Olympiastadion of Berlin, capacity 70+ thousand, plunges into darkness and mass panic breaks out. But maybe the power outage isn't total and its results not as dramatic after all. Nevertheless, if payment and security systems failed, Wi-Fi dropped, or the TV broadcast was disrupted, that would be inconvenient enough. Which is why an uninterruptible power supply is imperative for stadiums.
Large arenas are most often equipped with not just one, but a host of battery-based UPSs, and many also have their own diesel generator. Both individually and together, these systems are designed to keep critical equipment operational until mains power is restored. This includes the stadium's CCTV as well as other security installations, server rooms and communications equipment, fire control, lifts, emergency lighting, or payment and access systems.
They may have very different requirements in terms of power supply, some equipment being in peak use only shortly before and after the match, for example. Such a diverse load mixture thus requires a sophisticated back-up power plan which may include single-phase UPSs ranging from small rackmount units to larger ones sized to supply lighting systems with power demands in the hundreds of kVA. Various electronics including IT equipment requires three-phase UPSs to back them up, which may either serve these systems individually, or be centralized into one larger UPS.
In large stadiums, the battery backup may be sized for 10, but even 30 minutes, and for longer runtimes be supported by a standby generator. Such a generating set is provided with enough fuel to last for several hours, sometimes up to ten or more, in order to cover not just long duration power cuts, but why not also planned power outages. Altogether, the back-up system of a large stadium is as highly sophisticated as it is robust, because if you cram tens of thousands of people into a tightly confined area, nothing must go wrong.