Re: Would you invest???
I can't believe I missed this thread . . . This happens to be what I do for a living. Natural Gas for heavy trucks. Some comments:
1) Home refueling for CNG is still around. Owned by Impco now:
http://www.impcotechnologies.com/fuelmaker.asp
2) Oil and Natural Gas pricing have "decoupled" due to shale gas. It is expected that $4 - $5 per million btu will be around for a while regardless of what oil does. We have a glut of natural gas in North America now, and unlike oil, it is hard to get rid of. Yes I know about LNG, way too much to type here. But you can't simply start shipping LNG all over the place if you do not have liquefaction near export terminals. We have neither. Soooo? Glut for a while.
3) It takes roughly 125,000 btus to equal a gallon of Gasoline (HHV). Do the math. Then you have to add costs for profit, transportation (pipeline), local taxes, local gas rates etc. etc. Even with all of that you can make a good case for a $1 gallon savings at a retail station and some are a lot better than that.
4) Light duty (cars) are generally a poor choice for conversion. That's why we do trucks. Say you go 20,000 miles a year, and you get 20 MPG. That's 1000 gallons. So you have the potential to save $1000 per year ($1 per gallon benefit). How much is the station (Phill) and the stuff for the car car premium? Pretty simple math from there . . .
5) Propane is a by product and also a minor component in most natural gas. There is a gagillion times more methane (natural gas) than propane on the planet.