Modular Generator Pods Solve the Problem
The new technology is built-in parallel generating support, in which the electronics necessary to sync the generators and provide N+1 or even N+2 failover is built into the device at the factory. Generac is now incorporating this technology into modular generator designs that allow what Gibson calls "pods" of generators that can consist of several modular units grouped together to power all or part of a data center. According to Gibson, the latest practice is to power a data center with several pods, each connected to a part of the data center but isolated from each other to provide additional redundancy.An additional advantage to running smaller generators is that the smaller engines that power them don't need to be the huge railroad locomotive-scale diesels you see in the big data center emergency power centers. Because of their smaller size, these engines can run on natural gas, which has significant environmental benefits and a virtually unlimited supply of fuel. One of the concerns of the data center managers at 1&1 is that, despite their massive fuel tanks, they only had about three days of running time, which meant that a fuel truck would need to come by to refill the tanks during that time. During some natural disasters (big snowstorms, for example), big trucks might not be able to get there. The ability to use natural gas eliminates that problem. But sometimes it helps to have both, and with the new engines, it's possible to design them so they can run on diesel fuel or on a mixture of diesel and natural gas, significantly extending the runtime of the emergency generators. "Parallel generation has existed for years in larger installations," Gibson said, "but we're trying to make it less painful for midrange and smaller players." The result is that small and midsize organizations can have the same level of confidence in their emergency power as their larger counterparts.
This new modular approach to emergency power provisioning means that each pod can comprise relatively small generators working together as if they are a single machine, but protecting against the failure of any single device within the pod. It also means that relatively small data centers can have redundant emergency power where once they were forced by economics to rely on a single generator set and just hope that the one generator would keep running.