Liquid natural gas storage facility on Sabine Pass in Cameron Parish, Louisiana, US (Image: Matthew D White/Getty)

Better out than in. For the first time in 50 years, the US will build a plant to export natural gas. Gas producers hope this will help them offload an unprecedented gas glut, which has slashed prices to economically unsustainable levels.

Texas-based Cheniere Energy will build a liquefaction plant at its Sabine Pass site in Louisiana. This will convert natural gas into liquid that can be shipped abroad, and could be ready by 2015 after regulators approved it on Monday. The US, historically an importer of gas, could become a net exporter by 2021, says the US Energy Information Administration.

This is all down to hydraulic fracturing, or fracking, which is used to extract gas from otherwise uneconomic shale. Fracking has been so successful that the US now has too much gas, causing prices to tumble to a decade low.

“The current price levels are unsustainable,” says Howard Rogers of the Oxford Institute for Energy Studies in the UK. Exporting the excess may be the only way for fracking companies to make money.