Natural gas utilization peaks in the summer months for electricity generation for cooling and in the winter months for heating. Nonetheless, the winter remains the season with the highest demand. Because supply can not be turned on and off seasonally but rather, it is driven by E&P exploration programs, large storage facilities are used to act as a buffer in order to smooth out the seasonal consumption patterns.
Natural gas is held in storage in North America over the different seasons. It is pumped in during the low consumption summer and pumped out during the winter. Three types of underground facilities are mainly used:
Depleted reservoirs: Depleted reservoirs in oil and gas fields are the most commonly used storage facilities, since they are widely avilable, often close to consumption centres and offer existing available infrastructure and connection to an existing pipeline network.
Aquifers: Water bearing sedimentrary rock formation overlaid by impermeable cap rocks are often suitable to store natural gas.
Salt cavern formations: Salt dome formations in the US Gulf Coast states have been used for natural gas storage because they offer appealing high withdrawal an injection rates relative to their working gas capacity.