Join ORR Protection experts Lee Kaiser and Aaron Wille as they discuss Lithium-Ion battery safety and fire suppression systems for battery energy storage systems, like those found in data centers.
In this part of the series, our experts will explore specific challenges faced with using Lithium-Ion batteries by answering the following questions:
- 1. What are some of the biggest challenges of data centers moving from Lead-acid to Lithium-Ion battery storage?
- 2. In data center environments with distributed UPS, how is the fire protection and suppression design affected and how is that affected by NFPA 855 requirements?
- 3. How do we dispose of batteries that have gone through thermal runaway?
You have tons of data centers that are getting rid of their lithium or their lead acid batteries and moving towards Lithium-Ion. Obviously, 855 applies, but what have you typically seen are some of the biggest challenges when customers are migrating to Lithium-Ion batteries? Honestly, the biggest problem we just kind of outlined a lot of what is required. It's just that they don't know that there needs to be any changes. I got to be honest, the battery system manufacturers and the sales groups that are out there helping to push Lithium-Ion battery technologies into the data center space, they've got a very strong convincing story that this is safe, and you don't need to do anything extra from a fire protection perspective. We have engineers that come to us and they're hearing the same story and they don't know who to believe. They don't know if the people that are talking fire safety are right or are the battery system manufacturers are right. Manufacturers have a lot of clout with the engineering community and honestly, if the manufacturer says it's so then they believe them.
But in this case, I don't think that's right. The same battery technology, same battery management systems that are going into the data center space, is the same stuff that's going into the energy storage space. There are really no differences between the battery management systems, the settings, the batteries. It's all the same stuff just used in a different application. We can see because of the scale of the energy storage application of Lithium-Ion batteries, they're having fires. Not saying they're having a lot for the scale of how many batteries are out there, but what they're having is severe and that's coming to the data center world. We think that there was a big data center fire in France at the OVH Cloud facility in Strausberg, France, far western France near Germany.
We think that Lithium-Ion batteries were involved in that. We know so far from the news reports that the UPS systems were involved. We don't know if it was the actual UPS units where there was a capacitor fire in the UPS, which by the way, Aaron, I'm sure you can say, when we go out to a UPS fire, it's usually the capacitors that have burned up. That may have been the cause, but because of the severity, it's likely that Lithium-Ion batteries were involved. That's what some of the early whispers were but, nothing definitive on that fire has come out.
I think that's an important point because the battery manufacturers obviously have the battery management system and the UPS system typically has some type of management system, and that includes a thermal runaway prevention circuit with their heat detection. But that's just protecting an event that would start from within the UPS system. It's not necessarily capturing any type of early warning for a thermal runaway that could happen outside of the battery cabinet and then migrate into the battery cabinet. Do you want to talk any about that?
You’re just talking about regular old fire protection. These rooms are full of power. It's all kinds of DC power. It gets converted to AC that gets used. There's electrical gear and all of those things can have fires and it's a fire in one of those things that can expose itself to the Lithium-Ion batteries and cause them to overheat, which is one of the failure modes.
The BMS system wouldn't necessarily detect that fire until it’s too late, right?
Oh yeah, absolutely. That’s why still regular old fire protection that we do in battery rooms we've done for years still applies. Smoke detection systems even the early warning VESDA systems that apply and, then fire suppression, not only sprinklers. That’s why clean agents shouldn't really be ruled out for these because clean agents can put those fires out, stop them in their tracks, and then the fire doesn't expose itself to the Lithium-Ion batteries.
We've talked a lot about how to protect UPS rooms or electrical rooms that contain energy storage systems, specifically Lithium-Ion energy storage systems, where you've got a centralized UPS system, so all the batteries are in a dedicated battery room or a dedicated UPS room. We see a lot of data center environments where they have distributed UPS, so you'll have the batteries next to the servers in the data hall or inside the white space. You may not necessarily have a lot of batteries adjacent to each other, but you still have a lot of batteries in the space. When you move towards a distributed UPS system, how does that impact both the way we would want to design a detection system and a suppression system for that space? And do they still have to meet the requirements of an NFPA 855?
We're getting asked that question frequently. There are engineers out there that are designing their data centers with close couple UPS systems where you've got the UPS right in the rack and therefore the batteries right in the rack. To figure out if 855 applies or not, as we have said answering questions here today before, do you have enough battery capacity to kick it in? Above 20 kilowatts per hour for Lithium-Ion batteries, it's going to be required. Most of these big data centers are, they're going to have enough batteries for it to be required. You move the hazard out of a dedicated room to the racks. They do that for reasons. There are good valid energy reasons to do that good from an electrical distribution standpoint, but 855 now applies and all the things that we've talked about as far as requirements for passive fire protection, fire suppression, fire detection, and explosion prevention systems.
Now, all that moves to the white space where the servers and hard drives are, and all that stuff is there and applies. What I really worry about in that situation, is if a fire does occur, then there's no way to limit the damage to the function of the data center, just to the battery room. Now it's where the computing is occurring and all of that is now exposed to it. It’s a risk play. They get a chance to have a lower power utilization because they can bring higher voltage right to the rack. We don't need to teach engineers about how to design electrical for data centers. That's not our role, but that's why they're doing it. From a fire protection standpoint, everything that's in the 855 code that would be in a battery room, now it's got to happen in the server room itself.
It seems like it'd make it harder to detect the off-gas in a large open
space. Yeah, you'd think that but, from the testing, we're most familiar with lion tamer, not the only game for off-gas detection but, the leader out there and they test under high airflow conditions. We’ve been to their factory in Ohio. We’ve seen their test facilities. They test under high airflow conditions, which is what you'd have in that situation. Especially if the UPS unit where the battery batteries are right at the bottom of the rack, which is usually how it gets installed, then you just move the lion tamer sensor closer, so that it can catch that. You don't keep it up at the top of the rack like you normally do when it's a fully populated rack like we've done in other data center applications. You put it down close to the battery so that it's got the best chance of sensing the electrolyte vapor that comes off when a battery fails and then to deliver 0.3 gm, and let it flow, that water is going to go, and go, and go if there's a battery fire as fire departments will cautiously approach it. It’s going to flow in that data center. When my home internet doesn't work, or the certain service that I like to use, an app doesn't work, I go to downdetector.com. Your data center and your applications are going to be on down detector because the water's flowing and it's going to be pegged at the red — “No service.” I worry about that for data centers.
I have one last question. Do we know yet how to properly dispose of Lithium-Ion batteries that have gone into a thermal runaway after they've been discharged and safely extinguished?
I think fire departments are learning how to do it. They're learning from car fires, right? When your electric car catches on fire, there are fire departments out there that basically have a swimming pool on wheels. It's a modified storage container that they can roll off a flatbed truck and they can pull the car that's been on fire into it, and then they start filling it with water and they make a swimming pool to bathe it. Now in the built world, I'm not sure we've got that figured out, but I do know there are companies out there that know how to handle their batteries in those situations. It’s a very laborious process and slow and done painstakingly so there's not additional fires and it's going to be a big process if it happens in a UPS application — it would be in an energy storage application. I think fire departments are better with mobile devices, mobility units, and electric cars. We don't have it figured out for these other batteries.