U.S. natural gas consumption since 1997 reflects shifting patterns. Total U.S. natural gas consumption rose 7% between 1997 and 2011, but this modest growth masks bigger changes in individual sectors. Electric power is now the largest natural gas consuming sector and it shows perhaps the greatest sensitivity to price changes. The graphics below highlight key factors that influence natural gas consumption.
The electric power sector has the flexibility to shift some amount of baseload power generation, much of which has traditionally been fueled by coal, to underutilized natural gas generators without requiring additional investments in infrastructure.
Natural gas consumption for power generation is expanding. An earlier Today in Energy article noted that consumption of natural gas for electric power (or "power burn") has exceeded natural gas consumption in the industrial sector since early 2009. The power sector added a significant amount of new natural gas fired generating capacity over the last decade, much of which was in the form of efficient combined cycle units.
For many years, while coal fired generation was less expensive, those natural gas fired combined cycle units were used at relatively low rates. Recently, with natural gas prices declining and coal prices rising, dispatching natural gas generators in some parts of the country has become increasingly competitive with running coal generators. Competition between natural gas and coal appeared first in the Southeast, where coal fired power was more expensive due to the cost of transporting coal over long distances.
Domestic and global macroeconomic trends affect industrial activity, which is often tracked by industrial indices. However, some U.S. manufacturers (e.g., petrochemicals) that use natural gas derived feedstocks (e.g., ethane) are enjoying a competitive advantage while international competitors consume more expensive, oil derived feedstocks.
Residential and commercial consumption of natural gas is primarily for space heating, water heating, and cooking; the most influential short term factor for these sectors is weather (quantified here as heating degree-days).
The residential and commercial sectors have limited short-term flexibility to take advantage of inexpensive natural gas, as heating systems can be expensive to modify and are replaced infrequently. Over longer timescales, the number of households using natural gas for space heating has increased, for example, in the Northeast, households are switching their heating fuel from heating oil to natural gas. However, the increasing efficiency of home heating systems (lower average gas use per customer) masks some of the effect of the increasing number of natural gas customers, even when normalized for weather.
Seasonal patterns in natural gas consumption appear in all sectors. Colder winter weather means more natural gas consumption for space heating, and warmer summer weather leads to increased consumption in the power sector with increasing demand for air conditioning.
This should create some controversy, when is the best time of day to profit?