Natural Gas Fuel Reliability for Backup Power
Reliability of fuel supply tends to be of great concern for authorities having jurisdiction (AHJs). On-site fuel (most often diesel) is typically required for life-safety applications, and many mission-critical applications like 911 call centers specify it because it is perceived to be more reliable. Nonetheless, maintenance issues and delivery concerns of diesel fuel in an emergency, combined with the reliability and cost effectiveness of natural gas, must be considered in a standby power system. NFPA and NEC offer provisions for the use of natural gas in standby power applications that had previously been the clear domain of diesel-fueled systems. There are also many ways to work with the AHJ to clear the way for the use of gaseous fuel in a standby power system.
Historically, choosing between diesel-fueled and natural gas-fueled gensets has been relatively clear-cut. Power density, large-kW application cost advantages, and perceptions of reliability have made diesel the primary fuel of choice for large commercial and industrial standby applications.
However, natural gas-fueled gensets are becoming more powerful and more cost effective. Fuel storage, environmental, and diesel delivery issues are making system designers, electrical contractors, and electrical engineers as well as owners and operators seek alternatives to diesel-fueled gensets.
When selecting or specifying either gaseous- or diesel-fueled gensets, however, one must consider the reliability of the fuel infrastructure, regulatory issues, and how local authorities perceive and regulate these fuel choices.