Comment by Johnny555

For outages the generatos are great but I'm not sure how they assist with brownouts unless they can start instantly

If the generators will help in an outage, why wouldn't they help in a brownout? You'd transition to generator when the voltage and/or frequency is outside of spec.

You'd typically have some short-term power protection to keep your datacenter running until the generators start.

I was skeptical about a datacenter that had less than 60 seconds of flywheel energy storage. But the data center manager said that if the generator doesn't start within 30 seconds, you're not going to get it started in an hour so having a huge battery stack that can power the datacenter for 15 minutes isn't going to help much.