We own and operate a marine terminal located on the Houston Ship Channel that can load cargoes of fully refrigerated, low-ethane propane and/or butane (collectively referred to as LPG) onto multiple tanker vessels simultaneously. In December 2015, we completed a new refrigeration train that increased the terminal’s loading rate for LPG (nameplate capacity) from 16,500 barrels per hour to approximately 27,500 barrels per hour. Completion of this expansion project increased overall loading capabilities at the terminal from 9.0 MMBbls per month to 16.0 MMBbls per month. Our LPG export services continue to benefit from increased NGL supplies produced from domestic shale plays such as the Eagle Ford Shale and international demand for propane as a feedstock in ethylene plant operations and for power generation and heating purposes. On average, LPG loading volumes at this export terminal were 299 MBPD, 248 MBPD and 231 MBPD during the years ended December 31, 2015, 2014 and 2013, respectively.
The primary customer of our Houston Ship Channel LPG export facility is our NGL marketing group, which uses the terminal to assist its export customers in meeting their volume requirements. NGL marketing transacts with these customers using long-term sales contracts with take-or-pay provisions and/or exchange agreements. In recent years, the U.S. has become the largest exporter of LPG, with shipments originating from our Houston Ship Channel terminal playing a key role. We expect our export-related sales volumes to increase over the next few years due to existing customer commitments and expanded capacity at our Houston Ship Channel LPG export terminal.
We also own and operate an NGL import facility located at the same terminal as our Houston Ship Channel LPG export terminal. This import facility can offload NGLs from tanker vessels at rates up to 14,000 barrels per hour depending on the product. Our NGL import volumes were minimal during each of the years ended December 31, 2015, 2014 and 2013.
In April 2014, we announced plans to construct a fully refrigerated ethane export facility on the Houston Ship Channel near La Porte, Texas. When completed, the facility, which is supported by long-term contracts, is expected to have an aggregate loading rate (nameplate capacity) of approximately 10,000 barrels per hour and be integrated with our Mont Belvieu NGL fractionation and storage complex. We expect the ethane export facility to begin operations in the third quarter of 2016.
Our ethane export facility will provide new markets for domestically-produced ethane, and will assist U.S. producers in increasing their associated production of natural gas and crude oil. We estimate that U.S. ethane production capacity currently exceeds U.S. demand by 400 to 500 MBPD and could exceed demand by up to 700 MBPD by 2020, after considering the estimated incremental demand from new third party ethylene facilities that have been announced for the Gulf Coast.
For more information on the assets, please refer to the most recent Form 10-K or Quarterly Reports on Form 10-Q and other SEC filings.