The DOE authorized Driftwood and Port Arthur to export up to up to 3.88 billion cubic feet per day (bcfd) and 1.91 bcfd of natural gas as LNG, respectively, to any countries that do not have a free trade agreement (FTA) with the United States and that are not prohibited under US law or policy.

One billion cubic feet is enough gas to supply about five million US homes for a day.

Driftwood and Port Arthur each received authorization to build their projects from the US Federal Energy Regulatory Commission (FERC) on April 18.

DOE said the United States, which became a net exporter of gas for the first time in 60 years in 2017, has exported LNG to 35 countries.

There are three big LNG export terminals operating in the United States at Cheniere Energy Inc's Sabine Pass in Louisiana and Corpus Christie in Texas and Dominion Energy Inc's Cove Point in Maryland.

There are also liquefaction trains under construction at three other export terminals at Sempra's Cameron in Louisiana, Kinder Morgan Inc's Elba Island in Georgia and Freeport LNG's Freeport in Texas.

Looking at the plants under construction, US LNG export capacity is expected to rise to 7.4 bcfd by the end of 2019, and 10.0 bcfd in 2020, from around 5.2 bcfd now.

After not exporting any LNG at the start of 2016, the United States quickly became the world's third biggest LNG exporter by capacity by the end of 2018 behind Australia and Qatar.

Since 2010, the DOE has received about 70 applications to build LNG export terminals, totaling almost 58 bcfd of capacity. Of that total, the department has approved about 40 projects with a total export capacity over 22 bcfd.

The DOE is still reviewing about 20 projects, while 10 applications have been withdrawn.