US gas storage capacity increased slightly in 2016, according to the US Energy Information Agency, after a couple of years of marginal falls (see chart).
Design capacity of the 385 active storage fields increased slightly, growing 0.7%, from 4,658 billion cubic feet (Bcf) in November 2015 to 4,688 Bcf in November 2016. This increase resulted from a combination of expansions at existing facilities, reclassifications from base gas to working gas, and the restoration of an inactive facility to service. No new storage facilities have entered service since 2013.
The EIA said that for the past three years, underground natural gas storage capacity in the Lower 48 states had shown only changes compared to those in 2012 and 2013. This is probably a reflection of long-term trends, such as higher levels of gas production, the proximity of production to consuming markets in the Northeast and Midwest, and the lower price premium for natural gas during the winter, said the EIA. These trends may reduce reliance on storage as a source of supply during periods of elevated demand, such as during cold winter months.
EIA has published updated estimates of storage capacity based on data for the end of November, which is normally when storage levels have reached their highest points for the year. EIA uses two distinct measures of natural gas storage capacity: design capacity and demonstrated working natural gas volume.