Hacker News new | comments | show | ask | jobs | submit login

Compressed natural gas (ie, not liquefied) is the runner-up to purely battery electric vehicles. The problems are short range (go read the reviews of the Honda Civic GX: the range is comparable to the middle battery option in a Tesla Model S) and lack of natural gas stations.

The second problem can be partially ameliorated by filling at home with a high-pressure compressor (runs on electricity) fed by the same pipe that brings natural gas for your furnace and stove. Unfortunately, that still requires you to plug in the car overnight, just as you would with an electric, because fast high-pressure compressors are still very expensive. The compressor, by the way, costs more than an 80A EVSE for an electric car and adds range more slowly. There are a few public stations that store high pressure gas, but they tend to be at places like airports and taxi maintenance yards, where fleet vehicles congregate (check out Edmund's review of the Civic GX for refill times, though, they aren't nearly as fast as with gasoline). And compressing the gas still requires electricity. It is comparatively easier (and cheaper) to set up an EVSE (the "charger" stand, although it isn't really a charger) for an electric car than to run a gas line and install a gas compressor.

The first problem I mentioned doesn't really have a solution with a short time horizon: You need either more volume (a bigger car) or a tank that can hold more pressure (you think that everyone from SCUBA divers to NASA hasn't been working on that one for the last fifty years?).

Liquefied natural gas has it's own set of problems: people complain about the Tesla Model S losing a few miles of range while parked overnight, but the boil-off from a cryogenic container would be far worse (an uncovered dewar of liquid nitrogen boils off in "a few" hours; a big 150L dewar at 1 bar will last maybe two or three weeks).

It's not that I think natural gas is "bad," it's that as a physicist I can see that we already have technologies that work better (albeit slightly more expensively for now). The only thing natural gas seem to have going for it at the moment is that it is slightly cheaper[1] than a battery-powered car. Unless there is a new and obviously-practicable way to greatly improve the inferior technology in a short amount of time, I don't understand why it is worthwhile to spend money developing it.

[1] The Civic GX seems be to only available in jurisdictions (like California) that require a manufacturers to sell a certain number of "zero emissions" vehicles. Thus, it is probable that Civic GX's are "compliance cars" and that Honda takes a loss on each one sold. If you want to know this for sure, wait a few years until the full restrictions kick in and all "zero emissions" cars are required to actually have zero emissions: If the GX is still sold by then, I'll concede that it is a viable product (though I'd still rather spend my money on a something like a Leaf at that price point).




Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | DMCA | Apply to YC | Contact

Search: