A new white paper from Wartsila advocates the use of gas generators, rather than diesel-powered, as an option for emergency power in the data centre.

The paper claims that state-of-the-art gas engines have a similar speed to startup in an emergency as the more prevalent diesel version, but unlike a diesel engine, a gas-fired engine can be used to generate power in situations other than in emergencies, helping to increase overall energy savings.

Initially, speed to startup was a barrier to the selection of natural gas over diesel generators. In an emergency situation, it is important for a data center to have full redundancy to eliminate any downtime, which would negatively affect customers and users. Until very recently, it could take more than ten minutes for a gas-fired generator to reach capacity, and running a data center UPS on battery power for the ensuing time to guarantee redundancy could be cost-prohibitive.

However, the Wartsila paper claims, in recent years gas engines have been improved, and now have a similar speed to startup as the diesel version.

Natural gas can be piped directly to the data center generators, eliminating the need for fuel storage, and is a cleaner and cheaper alternative to diesel. However, the main argument against the use of gas generators over diesel is that in the event of a natural disaster, the supply of natural gas will be affected as well. A disaster, such as a hurricane, snowstorm, or flood, that affects a data center’s connection to the power grid will likely disrupt the facility’s connection to natural gas supply as well.

For example, last week’s Hurricane Harvey caused Gulf area natural gas production to shut down, resulting in higher prices and a curtailed supply of gas at the same time that a disabled power grid was sending demand skyrocketing.

The most distinct advantage Wartsila poses for choosing natural gas over diesel generators for data center backup is the fact that a data center could switch off from the power grid voluntarily, using natural gas as the primary power source for the facility. Natural gas could provide a low-cost alternative to regular electricity supplied by the local power grid as a primary power source, or it could be used to supplement green, but irregular power sources such as wind or solar. However, data center designers and operators must weigh this potential against the possibility of disruption of supply in the event of a disaster, just when the need for backup energy is the greatest.