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Prices for Hydrocarbon Gas Liquids

chart showing spot prices for motor gasoline, natural gas, and HGL products, 2002-14

Hydrocarbon gas liquid prices are related to oil and natural gas prices and related to supply and demand

Prices for hydrocarbon gas liquids (HGL) are related to their sources (crude oil and natural gas) and are related to their demand and supply. Until 2009, U.S. spot prices for natural gas and crude oil were closely related, in terms of dollars per million British thermal unit (Btu), and the U.S. spot price for propane generally tracked closely to the spot price for West Texas Intermediate (WTI) crude oil. This historical relationship, which reflected international market trends, was based on the general assumption that most fuels are interchangeable, as well as the fact that the United States was a net importer of propane and other HGL products, and therefore prices of HGL in the United States were bound by international market dynamics.

In 2011, the spot prices of propane at the Mont Belvieu, Texas trading hub began to move away from the spot prices of crude oil and refined products such as gasoline and naphtha (on a dollar per Btu basis). Initially, this move reflected the switch in the U.S. trade position from a net importer to a net exporter of propane. By 2013 and 2014 the surplus of propane stocks in the United States (that resulted from continuing increases in production, particularly from natural gas processing plants) began to exceed the capacity of export terminals to send the product to overseas markets, depressing the U.S. price of propane even further.

Normal butane prices began to exhibit similar behavior in early 2012, and isobutane prices began to fall closer to propane by early 2013, reflecting the high cost required to move U.S.-produced HGL to overseas markets. Although in absolute terms (dollar per Btu), the difference between liquefied petroleum gas prices in the United States and in the international market has narrowed, because of the decline in crude prices and high transportation costs to distant markets overseas, the relative discounts (in percentage terms) are at historical highs.

U.S. spot prices for ethane generally tracked crude oil spot prices until 2008. Gradually, as production growth in the United States overwhelmed the ability of the domestic petrochemical industry to increase its consumption of ethane, the price of this commodity delinked from crude oil prices, and since mid-2012, began to closely track natural gas prices. Because the only alternative market for ethane currently is as a component of pipeline natural gas (known as ethane rejection), current ethane prices reflect its heating value.

Last reviewed: December 28, 2015

chart showing U.S. average monthly propane prices, October 2005 to March 2015
Image of Average monthly residential propane prices by region1, October–March, 2010 to 2015

Retail propane prices are affected by several factors

In addition to the factors that affect wholesale propane prices, two other major factors affect the retail price for propane:

  • Levels of available supply sources relative to demand
  • Transportation costs

Propane supply and demand

Propane production is generally consistent throughout the year, because it results from crude oil refining and natural gas processing. Propane consumption, on the other hand, is highly seasonal. Propane stocks, or inventories, are generally built up during the spring and summer when consumption is lowest. The stocks are then used to meet propane demand in the autumn and winter when consumption is highest. Production and stocks are supplemented by imports. Wholesale and retail propane prices can increase quickly and significantly when supply sources are insufficient or when they lack the capacity to respond quickly to large and/or rapid increases in demand.

Transportation costs

Propane consumers who are the farthest from the major supply sources will generally pay higher prices for delivered propane. This is because of the increased cost to transport propane by pipeline and by rail to bulk distributors, and from bulk distribution points to individual consumers. Congestion along rail and water routes, especially in the winter, can contribute to price increases.

Propane prices have historically been higher for consumers in states located in the U.S. East Coast region because they are farthest from sources of propane supply. Consumers with smaller onsite propane storage capacity, such as residential and commercial consumers, generally pay higher prices per gallon for propane because propane has to be delivered by truck in smaller quantities. As with most delivered fuels, the unit price (in cents per gallon) for propane is generally lower when the volume delivered is larger. Consumers in the most remote locations typically pay the highest prices for propane.

Case study: U.S. propane prices in the winter of 2013–14

Retail propane prices spiked in the winter of 2013–14 as a result of a confluence of factors. A late and large corn harvest in 2013, along with cold, wet weather, resulted in strong demand for propane by farmers in the Midwest for grain drying. After the harvest, logistical issues along supply pipelines and rail lines prevented propane stocks in the Midwest from being fully replenished before the onset of winter.

The early, and sudden, arrival of cold weather during the first half of the winter (October through December), especially in the Midwest, caused increased propane demand for space heating at a time normally used by retailers to replenish inventories before the start of the winter heating season. The low stocks, along with out-of-the-ordinary logistical constraints and increased demand, resulted in large increases in residential propane prices.

In the fourth week of January 2014, the U.S. average residential propane price reached a record of more than $4.00 per gallon, almost 75% higher than the price in the same week of 2013. The average residential price in the Midwest reached nearly $4.20 per gallon, 137% higher than the price in the same week of 2013. Prices then dropped when the supply constraints and demand eased.

Last reviewed: March 3, 2016