LNG Pros & Cons

Cons: It's non-renewable and won't last forever. May have peaked already.

Cons: While it is greener than coal or oil, it isn't green. There are still emissions we don't want in the air.

Cons: It might be cheaper now, but it won't stay that way. The price will go up as the supplies go down, just like every other non-renewable.

 

If you could find someone to make the conversion, you'd have zero trunk space after the conversion, and the tank would have to ride way up high above most of the framing of the car (because you can't displace the battery). You'd be able to see that big CNG tank through the windows. That doesn't strike me as a good thing. There's no way I would consider a one-off conversion to CNG, as a practical matter.

For reference the CNG civic tank is 6 cubic feet. That'd be a cylinder 3' long and a little over 1.5' in diameter. I think that would have to fit in the back, above the battery, if you wanted to run the car on CNG. Maybe they could pull the gas tank and fit a tank there, but I doubt you'd be that lucky.

For a purpose-built CNG car like the Civic, compare it on Fuel Economy. Ignoring the loss of trunk space, the limited mileage on a tank, and so on, it's just not efficient. It's cheap because natural gas is cheap(er) right now, but it's not as if you get more miles out of the available hydrocarbons. But it does burn clean.

In the broader picture, I agree with others who have said that the best thing to do with natural gas is heat your home with it. There, with a modern furnace, 80% (for a traditional furnace) or 90% (for a high-efficiency condensing furnace) of the energy in the gas gets used. Put it in a car, and you use 15-20% and exhaust the rest.

If its a limited resource, seems to me that running cars on it is not the way to go. I'd rather have to walk than have to freeze, if it comes to that.

On the plus side, supplies are more secure. If oil runs out sooner than natural gas (which would be the bet at the moment), or if a hurricane reduces gasoline production, then you can still drive while others can't.

On net, I don't think a one-off conversion of a Prius would be practical, and in general, I don't think it's a good idea in the grand scheme of things. But it's cheap and relatively plentiful right now.

 

Cleaner than gasoline, but still contributes to the atmospheric load of CO2. Less convenient, due to the lack of filling stations. A home filling station limits you to a radius of the range of half a tank -- or a bit less to be safe. Mostly it's a domestic resource, whereas gas is largely imported from people who don't like us.

Bottom line: better than gasoline if range and filling are not an issue, but probably not worth converting an existing Prius, IMO.

My personal preference by far would be an EV (which is what I drive most days, when my 40-mile range is adequate).

 

An EV powered by a NG plant would be far more efficient than CNGV. Of course, the CNGV is considerably cheaper, but NG prices would go nuts if we started pumping large quantities of it into our cars. It lends itself much more to static power generation than transportation fuel.

 

The trick is that it would dramatically increase electricity rates and fertilizer costs, so it would have a bit of a ripple effect, a lot like oil prices do. Petrol costs would also rise because NG is used to supply H2 for refining operations as well. I think that it makes more sense to aggressively pursue efficiency and alternatives than to try to switch to NG, which will have a pretty short shelf life as a viable alternative to oil.

 

I don't think we're at maximum capacity. I'm just saying that there is a lot of upward pressure on the price of NG. NG is increasingly being looked at by utilities and it's already getting pretty expensive (the price of NG is quite volatile). Here in CO Xcel Energy is raising their residential rates 28%, citing the rising cost of NG as the reason for the rate hike. I'm not sure where our domestic production stands. There are a number of untapped sources, but my understanding is that the existing fields are now starting to decline. I don't know what the turn around is on NG fields but I'm sure that it takes at least a few years to get into production at the very least.