CNG is not so expensive, but has reduced volume of gas compared to LNG. Most of our planned Natural Gas export terminals are LNG. We don't have any operational yet. They are mostly existing LNG import terminals that haven't built the Liquefaction units yet.
There is some CNG planned, not sure if any are operational yet, but they move less volume and the ships are rare.
We had a tiny LNG export out of Alaska for decades but it closed down a few years ago with the reduced natural gas production in the Cook Inlet area.
I meant LNG, but typed CNG because of a project I am working on now uses compressed NG. Brain fart.
The technology for LNG shipping exists. When I last played in the energy field we had some plans for it, but it was canceled when gas got cheap.
My favorite design was a tanker that had what looked like an arrangement of giant “eggs” on the deck for shipping. We were working on getting the LNG to them, not from the ships, so I didn’t get much of an insight into the ships themselves.
From there, I misspent some time in the ethanol market marking some of the best vodka on the market. Sadly, we didn’t have the marketing to capitalize on it.